Sofaconventions - User contributions [en]

User talk:Jwtest202601

2026-01-13T20:14:20Z

Petibub: Welcome!

'''Welcome to ''Sofaconventions''!'''
We hope you will contribute much and well.
You will probably want to read the [https://www.mediawiki.org/wiki/Special:MyLanguage/Help:Contents help pages].
Again, welcome and have fun! [[User:Petibub|Petibub]] ([[User talk:Petibub|talk]]) 21:14, 13 January 2026 (CET)

User:Jwtest202601

2026-01-13T20:14:20Z

Petibub: Creating user page for new user.

Here is my ten word long biography about nothing in particular

User talk:Jihan Liu

2025-02-28T17:46:50Z

Petibub: Welcome!

User:Jihan Liu

2025-02-28T17:46:50Z

Petibub: Creating user page for new user.

Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin,China

Files

2024-11-26T14:07:56Z

Petibub: SOFA API MO Test Files --> Archived

The [http://sofacoustics.org/data main SOFA repository] aims at collect the worldwide available HRTFs, BRIRs, DRIRs, and other SOFA-related data at a single place. It is just in the process of being created: Partial download, metadata access, and database search is not available (yet, we are investigating the possibility of using [http://www.opendap.org/ OPeNDAP] for SOFA repositories). Currently, the data can be accessed and downloaded as they are and the metadata are provided in the particular files.

== General purpose free-field [http://sofacoustics.org/data/database databases] (HRTFs, PRTFs) ==

===Standard (in-the-ear canal) HRTFs of humans===
* [http://sofacoustics.org/data/database/ari ARI]: HRTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database]. In-the-ear HRTFs and DTFs for over 220 listeners.
** hrtf, dtf: HRTFs and DTFs, respectively, equalized between 300 Hz and 18 kHz
** hrtf b/c/d, dtf b/c/d: HRTFs and DTFs, equalized between 50 Hz and 18 kHz for hi-fi auralizations ("b" vs. "c" and "d" differ each other in their starting positions and the order of measurement positions: b: 0°→0°, c/d: 270°→270°; subject being rotated clockwise ↻; "c" measurements were recorded until 2023 in the ARI lab in Wohllebengasse, "d" measuremens are recorded in the new ARI lab in Postsparkasse since 2024).
* [http://sofacoustics.org/data/database/ari%20(altb) ARI (ALTB)]: HRTFs from the ARI database. Measurements for some of the listeners from the ARI database, repeated and evaluated a few years later, see [http://www.researchgate.net/publication/236111930_Sound_localization_in_individualized_and_non-individualized_crosstalk_cancellation_systems Majdak et al. (2013)].
* [http://sofacoustics.org/data/database/ari%20(las)/ ARI (LAS)]: In-the-ear HRTFs and DTFs are measured in the ARI loudspeaker array studio (LAS). Each file contains HRTFs measured at 451 sound-source directions (91 directions as in [https://doi.org/10.3389/fnins.2023.1027827 McLachlan et al. (2023)]); but extended to 451 directions by rotating the listener four times).
* [http://sofacoustics.org/data/database/cipic CIPIC]: HRTFs from the [https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/ CIPIC database]. 45 listeners, partially [https://sofacoustics.org/data/database/cipic/anthropometry.zip anthropometric data] available.
* [http://sofacoustics.org/data/database/riec RIEC]: Far-field HRTFs from the [http://www.riec.tohoku.ac.jp/pub/hrtf/index.html RIEC] database from the Advanced Acoustic Information Systems Laboratory, Research Institute of Electrical Communication, Tohoku University, Japan of over 100 human listeners. ''(Credit: Kanji Watanabe, Japan)''
* [http://sofacoustics.org/data/database/aachen Aachen]: HRTFs from the [http://www.akustik.rwth-aachen.de/go/id/lsly Aachen HRTF database], combined with anthropometric data and 3D ear models of 48 listeners. See the [http://gershwin.akustik.rwth-aachen.de/hrtf/hrtf-lic.php license]. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution)/ Aachen: High-resolution HRTFs] from the [https://publications.rwth-aachen.de/record/793261 Aachen HRTF database], combined with a [https://publications.rwth-aachen.de/record/793260 3D model] of one human listener. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/hutubs/ HUTUBS]: HRTFs from the [https://dx.doi.org/10.14279/depositonce-8487 HUTUBS] database containing anthropometric data, headphone impulse responses, and 3D head models from 96 listeners. The database acquisition is detailed in the accompanying [https://doi.org/10.17743/jaes.2019.0024 paper]. ''(Credit: Fabian Brinkmann, Berlin)''
* [http://sofacoustics.org/data/database/chedar/ CHEDAR]: Numerically calculated HRTFs (.sofa) with 3D meshes of the head and pinnae (.ply) and anthropometric data (.mat) provided. For more details, see the [http://sofacoustics.org/data/database/chedar/documentation.pdf documentation]. ''(Credit: Slim Ghorbal, France)''
* [https://sofacoustics.org/data/database/3d3a/ 3D3A]: Measured in-the-ear HRTFs (.sofa) of 38 subjects, and 3D head and torso scans of 31 subjects from the [http://www.princeton.edu/3D3A/HRTFMeasurements.html Princeton 3D3A Database]. ''(Credit: Edgar Choueiri, USA)''
* [https://sofacoustics.org/data/database/bili%20(dtf)/ BiLi]: Measured in-the-ear HRTF files (.sofa) of 56 subjects. Data are available in [https://sofacoustics.org/data/database/bili%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/bili%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/bili%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/crossmod%20(dtf)/ Crossmod]: Measured in-the-ear HRTF files (.sofa) of 24 subjects. Data are available in [https://sofacoustics.org/data/database/crossmod%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/crossmod%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/crossmod%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ Listen]: Measured in-the-ear HRTF files (.sofa) of 50 subjects. Data are available in [https://sofacoustics.org/data/database/listen%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/listen%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/listen%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/sadie/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 18 human subjects (indices H3 to H20). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs and anthropometric data ([https://sofacoustics.org/data/database/scut/AnthropometricParameters.csv CSV] and [https://sofacoustics.org/data/database/scut/AnthropometricParameters.pdf PDF]) of human listeners. ''(Credit: Guangzheng Yu & Yu Lan, China)''
* [http://sofacoustics.org/data/database/axd AXD]: HRTFs from the [https://www.axdesign.co.uk/tools-and-devices/sonicom-hrtf-dataset AXD/SONICOM database], for 200 listeners. More information about the measurement setup and validation can be found [http://www.aes.org/e-lib/browse.cfm?elib=22128 here]. ''(Credit: Lorenzo Picinali, London)''

===HRTFs of artificial heads===
* [http://sofacoustics.org/data/database/mit MIT-KEMAR]: HRTFs from [http://sound.media.mit.edu/resources/KEMAR/ MIT of the KEMAR] dummy head. Reference HRTFs used in many publications.
* [http://sofacoustics.org/data/database/ari%20(artificial) ARI (ARTIFICIAL)]: HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners:
** NH169: HRTFs, DTFs, and raw data of a printed head of the corresponding human listener
** NH172: HRTFs, DTFs, raw and reference data of the dummy head Neumann KU 100. Also part of Club Fritz, see below.
* [http://sofacoustics.org/data/database/thk THK/HRIR_*]: HRTFs of various mannequins provided by the Technische Hochschule Köln (TH Köln, previously Fachhochschule Köln); further details can be found here:
** [https://zenodo.org/record/3928297 Far-field HRTFs]: Gapless data, high spatial resolution HRTFs of Neumann KU 100. Files: HRIR_CIRC360, HRIR_CIRC360RM, HRIR_FULL2DEG, HRIR_L2354, HRIR_L2702.sofa ''(Credit: Benjamin Bernschütz, Germany).''
**[https://zenodo.org/record/4297951 Near-field HRTFs] (HRIR_*_NF*.sofa): High spatial resolution HRTFs of Neumann KU 100 done for various distances ''(Credit: Johannes Arend, Germany)''.
**[https://zenodo.org/record/3928465 Head-gear HRTFs of Neumann KU 100 and HEAD acoustics HMS II] (KU100*.sofa, HMSII*.sofa): High spatial resolution HRTFs while wearing various head gears ''(Credit: Christoph Pörschmann, Germany)''.
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs from SCUT database of the KEMAR (Radius: 0.2 to 1.0 m). ''(Credit: Bosun Xie, China)''
* [http://sofacoustics.org/data/database/tu-berlin TU-Berlin]:
** HRTFs from [http://doi.org/10.5281/zenodo.55418 TU-Berlin of the KEMAR] dummy-head. HRTFs for several distances (>0.5 m). ''(Credit: Hagen Wierstorf, Germany)''
** HRTFs from [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN] dummy-head. Acoustically measured and numerically calculated HRTFs. ''(Credit: Fabian Brinkmann, Germany)''
* [http://sofacoustics.org/data/database/clubfritz Club Fritz]: HRTFs of Neumann KU 100 measured as part of the Club Fritz project where many institutions measured the exact same artificial head, see [http://dx.doi.org/10.1109/JSTSP.2015.2400417 Andreopoulou et al, (2015)]. ''(Credit: Brian Katz, France)''.
* [http://sofacoustics.org/data/database/viking/ VIKING]: Full-sphere HRTFs (.sofa) from the [https://doi.org/10.5281/zenodo.4160401 Viking database]. KEMAR mannequin with 20 different pairs of artificial silicone pinnae attached, plus a "pinna-less" condition, measured for 1513 different directions. 3D scans of left pinnae are also included (.stl). ''(Credit: Simone Spagnol, Denmark)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution%20kemar)/ Aachen: High-resolution HRTFs of the KEMAR] dummy head from the [https://publications.rwth-aachen.de/record/807373 Aachen HRTF database], combined with a 3D model of one subject. ''(Credit: Janina Fels, Aachen)''
* [https://sofacoustics.org/data/database/pku-ioa/ PKU-IOA:] High spatial resolution in-the-ear HRTF database of the KEMAR dummy head with distance from 20 cm to 160 cm, including 20, 30, 40, 50, 75, 100, 130, and 160 cm. ''(Credit: Tianshu Qu, China)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 2 dummy heads (indices D1, D2). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* [http://sofacoustics.org/data/database/axd%20(kemar) AXD]: HRTFs from the [https://www.axdesign.co.uk/tools-and-devices/sonicom-hrtf-dataset AXD/SONICOM database], for the KEMAR head, for 2 ears. ''(Credit: Lorenzo Picinali, London)''
* '''New:''' [http://sofacoustics.org/data/database/AMU AMU]: HRTFs from 4 dummy heads, measured at 2 distances (40cm and 2m). Details can be found [https://hal.science/hal-03521905/document here]. ''(Credit: Adrien Vidal, Marseille)''

===Special HRTFs===
* [http://sofacoustics.org/data/database/ari%20(bte) ARI (BTE)]: Behind-the-ear HRTFs and DTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database].

===PRTFs===
* [http://sofacoustics.org/data/database/widespread Widespread] (Wide dataset of ear shapes and pinna-related transfer functions obtained by random ear drawings): 1005 pinna meshes matched with correspondingly calculated PRTFs from the [https://www.ietr.fr/spip.php?article1618&lang=en FAST team, IETR (CNRS UMR 6164), CentraleSupélec]. The meshes were created by varying principle components obtained from an analysis of 119 pinna meshes of actual listeners. The PRTFs were calculated by means of the boundary-element method for two spatial grids and three distances, see the upcoming publication [http://sofacoustics.org/data/database/widespread/Widespread.pdf (documentation)]. ''(Credit: Corentin Guezenoc, France)''.

== Directivities (sources and receivers) ==

===Sources===

* [http://sofacoustics.org/data/database/tu-berlin%20(directivity)/ TU-Berlin]: One data set of a 3-way loudspeaker (low- mid- and high-unite) in 10°x10° resolution, and two data sets of a trumpet, recorded with a 32 channel microphone array, from the TU Berlin. ''(Credit: David Ackermann, Germany)''

===Receivers===
* TBA

== Room impulse responses [http://sofacoustics.org/data/database databases] (DRIRs, SRIRs, BRIRs) ==

RIRs/BRIRs/DRIRs:
* [http://sofacoustics.org/data/database/oldenburg Oldenburg] DRIRs from [http://medi.uni-oldenburg.de/hrir/html/download.html Oldenburg]. Recordings in an office under several conditions ''(Credit: Stephan Ewert and Daryl Kelvasa, Germany)''.
* [http://sofacoustics.org/data/database/tuburo TuBuRo]: RIRs (from omnidirectional mic) and BRIRs (from KEMAR) recorded with 64-channel loudspeaker array in a room under various absorbing conditions, see [http://dx.doi.org/10.14279/depositonce-87.2 the source], [https://depositonce.tu-berlin.de/bitstream/11303/245.2/11/AdditionalInformation.pdf notes on the file naming] and [https://secure.aes.org/forum/pubs/ebriefs/?elib=17624 Erbes et al. (2015)]. ''(Credit: Vera Erbes, Rostock, Germany)''.
* [http://sofacoustics.org/data/database/sbsbrir SBSBRIR]: BRIRs from the [http://www.bbc.co.uk/rd/publications/sbsbrir Salford-BBC dataset] measured in a recording room for 12 loudspeakers, each for 15 head orientations ([http://usir.salford.ac.uk/30868/ details]). ''(Credit: Chris Pike, Salford)''.
* [http://sofacoustics.org/data/database/thk THK/DRIR_* and THK/BRIR_*]: DRIRs and BRIRs measured at the WDR broadcast studios with various microphone arrays provided by the Technische Hochschule Köln (TH Köln). For description, see [https://zenodo.org/record/3930833 here]. ''(Credit: Johannes Arend)''.
* [https://sofacoustics.org/data/database/room%20transition%20dataset/ Room Transition dataset]: SRIRs capturing the transition between coupled rooms with 101 positions and four coupled room pairs. For description, see [https://doi.org/10.5281/zenodo.4095493 here] ''(Credit: Thomas McKenzie, Aalto)''.
* [https://sofacoustics.org/data/database/6dof%20dataset/ 6DoF dataset]: SRIRs measured in a variable acoustics room with two spherical microphone arrays. For description, see [https://doi.org/10.5281/zenodo.5720723 here]. ''(Credit: Thomas McKenzie, Aalto)''.
* [https://sofacoustics.org/data/database/kaist-iem/ KAIST-IEM dataset]: 6 DoF DRIR dataset measured over a dense loudspeaker grid (6DRIR-DL). For description, see [http://www.aes.org/e-lib/browse.cfm?elib=22184 here]. ''(Credit: Jung-Woo Choi, KAIST, Korea; Franz Zotter, IEM Graz)''.
* [https://sofacoustics.org/data/database/bbc%20maida%20vale/ BBC Maida Vale dataset]: 6 DoF DRIR dataset, measured from the BBC Maida Vale Studios, stored in SH format, available as SingleRoomSRIRs and SingleRoomMIMOSRIRs. For description, see [https://doi.org/10.5281/zenodo.10020866 here]. For full paper, see [https://doi.org/10.3390/acoustics4030047 here]. ''(Credit: Gavin Kearney, University of York)''.
* '''New:''' [https://sofacoustics.org/data/database/tu-ilmenau%20(rooms)/ TU Ilmenau room configurations dataset]: A high spatial resolution dataset of spatial room impulse responses for different acoustic room configurations, available as SingleRoomSRIR. For description, see [https://zenodo.org/records/10450779 here]. ''(Credit: Stephan Werner, Ilmenau)''
* '''New:''' [https://sofacoustics.org/data/database/tu-ilmenau%20(robot)/ TU Ilmenau robot journey dataset]: Spatial room impulse response dataset: A robot's journey through coupled rooms of a reverberant university building, available as SingleRoomSRIR. For description, see [https://zenodo.org/records/10708306 here]. ''(Credit: Stephan Werner, Ilmenau)''
* '''New:''' [https://sofacoustics.org/data/database/pan-ar/ PAN-AR dataset]: dataset of spatial room impulse responses (SRIRs) measured using a spherical microphone array in 4 distinct rooms with different configurations of source and listener positions. In addition to the SOFA files, spherical pictures, planimetries, and ambient noise recordings are also provided. See the related [https://doi.org/10.1145/3678299.3678332 paper] and the [https://doi.org/10.5281/zenodo.13134270 alternate version of PAN-AR as wav files]. ''(Credit: Giorgio Presti and Davide Fantini, Milan)''

== Headphone impulse responses (HpIRs) ==

* [http://sofacoustics.org/data/headphones/ari ARI]: HpIRs of human listeners from the ARI database. Single headphone, five measurements (with repositioned headphone in-between) for over 100 listeners.
* [http://sofacoustics.org/data/headphones/btdei BT-DEI]: HpIRs of human listeners from the [http://padva.dei.unipd.it/?page_id=345 BT-DEI] database. 16 listeners, three headphones ''(Credit: Michele Geronazzo, Italy)''.
* [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN]: HpIRs of the FABIAN mannequin. Acoustically measured for 34 headphones. ''(Credit: Fabian Brinkmann, Germany)''.

== Example & Test SOFA Files ==

* [http://sofacoustics.org/data/examples/ Example files]: SOFA example & test files for stable [[SOFA_conventions|conventions]]; these files are a subset of other databases on this page, renamed according their conventions.
* [http://sofacoustics.org/data/sofatoolbox_test sofatoolbox_test]: HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA Toolbox v2.x]
* [http://sofacoustics.org/data/sofa_api_mo_test sofa_api_mo_test] (deprecated): HRTFs resulting from tests of the deprecated version of the [http://sourceforge.net/projects/sofacoustics/ SOFA API v1.x for Matlab/Octave]. These files are deprecated and in order to prevent them from being accidentally used, they are available as a zip file archive only.

== Other repositories ==

This is a list of other repositories providing HRTFs, BRIRs, and DRIRs available as SOFA files.

* ARI free-field HRTF database. HRTFs available for in-the-ear (ITE) and behind-the-ear (BTE) HRTFs. Link: https://www.oeaw.ac.at/isf/hrtf
* Example files created by the Matlab/Octave API. Link: http://tinyurl.com/sofaHRTFs
* [https://www.york.ac.uk/sadie-project/database.html SADIE]: Far-field HRTFs from the [https://www.york.ac.uk/sadie-project/ SADIE] project of over 20 human listeners. ''(Credit: Gavin Kearney, York)''

== Database missing? ==
If you want your/a SOFA database to be added please [https://www.sofaconventions.org/mediawiki/index.php/People_behind_SOFA contact Michael Mihocic or Piotr Majdak] for support.

Files

2024-08-20T09:54:45Z

Petibub: /* General purpose free-field databases (HRTFs, PRTFs) */

The [http://sofacoustics.org/data main SOFA repository] aims at collect the worldwide available HRTFs, BRIRs, DRIRs, and other SOFA-related data at a single place. It is just in the process of being created: Partial download, metadata access, and database search is not available (yet, we are investigating the possibility of using [http://www.opendap.org/ OPeNDAP] for SOFA repositories). Currently, the data can be accessed and downloaded as they are and the metadata are provided in the particular files.

== General purpose free-field [http://sofacoustics.org/data/database databases] (HRTFs, PRTFs) ==

===Standard (in-the-ear canal) HRTFs of humans===
* [http://sofacoustics.org/data/database/ari ARI]: HRTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database]. In-the-ear HRTFs and DTFs for over 220 listeners.
** hrtf, dtf: HRTFs and DTFs, respectively, equalized between 300 Hz and 18 kHz
** hrtf b/c/d, dtf b/c/d: HRTFs and DTFs, equalized between 50 Hz and 18 kHz for hi-fi auralizations ("b" vs. "c" and "d" differ each other in their starting positions and the order of measurement positions: b: 0°→0°, c/d: 270°→270°; subject being rotated clockwise ↻; "c" measurements were recorded until 2023 in the ARI lab in Wohllebengasse, "d" measuremens are recorded in the new ARI lab in Postsparkasse since 2024).
* [http://sofacoustics.org/data/database/ari%20(altb) ARI (ALTB)]: HRTFs from the ARI database. Measurements for some of the listeners from the ARI database, repeated and evaluated a few years later, see [http://www.researchgate.net/publication/236111930_Sound_localization_in_individualized_and_non-individualized_crosstalk_cancellation_systems Majdak et al. (2013)].
* [http://sofacoustics.org/data/database/ari%20(las)/ ARI (LAS)]: In-the-ear HRTFs and DTFs are measured in the ARI loudspeaker array studio (LAS). Each set of HRTFs contains 451 sound-source directions (91 loudspeakers by 5 subject roations), see [https://doi.org/10.3389/fnins.2023.1027827 McLachlan et al. (2023)].
* [http://sofacoustics.org/data/database/cipic CIPIC]: HRTFs from the [https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/ CIPIC database]. 45 listeners, partially [https://sofacoustics.org/data/database/cipic/anthropometry.zip anthropometric data] available.
* [http://sofacoustics.org/data/database/riec RIEC]: Far-field HRTFs from the [http://www.riec.tohoku.ac.jp/pub/hrtf/index.html RIEC] database from the Advanced Acoustic Information Systems Laboratory, Research Institute of Electrical Communication, Tohoku University, Japan of over 100 human listeners. ''(Credit: Kanji Watanabe, Japan)''
* [http://sofacoustics.org/data/database/aachen Aachen]: HRTFs from the [http://www.akustik.rwth-aachen.de/go/id/lsly Aachen HRTF database], combined with anthropometric data and 3D ear models of 48 listeners. See the [http://gershwin.akustik.rwth-aachen.de/hrtf/hrtf-lic.php license]. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution)/ Aachen: High-resolution HRTFs] from the [https://publications.rwth-aachen.de/record/793261 Aachen HRTF database], combined with a [https://publications.rwth-aachen.de/record/793260 3D model] of one human listener. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/hutubs/ HUTUBS]: HRTFs from the [https://dx.doi.org/10.14279/depositonce-8487 HUTUBS] database containing anthropometric data, headphone impulse responses, and 3D head models from 96 listeners. The database acquisition is detailed in the accompanying [https://doi.org/10.17743/jaes.2019.0024 paper]. ''(Credit: Fabian Brinkmann, Berlin)''
* [http://sofacoustics.org/data/database/chedar/ CHEDAR]: Numerically calculated HRTFs (.sofa) with 3D meshes of the head and pinnae (.ply) and anthropometric data (.mat) provided. For more details, see the [http://sofacoustics.org/data/database/chedar/documentation.pdf documentation]. ''(Credit: Slim Ghorbal, France)''
* [https://sofacoustics.org/data/database/3d3a/ 3D3A]: Measured in-the-ear HRTFs (.sofa) of 38 subjects, and 3D head and torso scans of 31 subjects from the [http://www.princeton.edu/3D3A/HRTFMeasurements.html Princeton 3D3A Database]. ''(Credit: Edgar Choueiri, USA)''
* [https://sofacoustics.org/data/database/bili%20(dtf)/ BiLi]: Measured in-the-ear HRTF files (.sofa) of 56 subjects. Data are available in [https://sofacoustics.org/data/database/bili%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/bili%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/bili%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/crossmod%20(dtf)/ Crossmod]: Measured in-the-ear HRTF files (.sofa) of 24 subjects. Data are available in [https://sofacoustics.org/data/database/crossmod%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/crossmod%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/crossmod%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ Listen]: Measured in-the-ear HRTF files (.sofa) of 50 subjects. Data are available in [https://sofacoustics.org/data/database/listen%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/listen%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/listen%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/sadie/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 18 human subjects (indices H3 to H20). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs and anthropometric data ([https://sofacoustics.org/data/database/scut/AnthropometricParameters.csv CSV] and [https://sofacoustics.org/data/database/scut/AnthropometricParameters.pdf PDF]) of human listeners. ''(Credit: Guangzheng Yu & Yu Lan, China)''
* [http://sofacoustics.org/data/database/axd AXD]: HRTFs from the [https://www.axdesign.co.uk/tools-and-devices/sonicom-hrtf-dataset AXD/SONICOM database], for 200 listeners. More information about the measurement setup and validation can be found [http://www.aes.org/e-lib/browse.cfm?elib=22128 here]. ''(Credit: Lorenzo Picinali, London)''

===HRTFs of artificial heads===
* [http://sofacoustics.org/data/database/mit MIT-KEMAR]: HRTFs from [http://sound.media.mit.edu/resources/KEMAR/ MIT of the KEMAR] dummy head. Reference HRTFs used in many publications.
* [http://sofacoustics.org/data/database/ari%20(artificial) ARI (ARTIFICIAL)]: HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners:
** NH169: HRTFs, DTFs, and raw data of a printed head of the corresponding human listener
** NH172: HRTFs, DTFs, raw and reference data of the dummy head Neumann KU 100. Also part of Club Fritz, see below.
* [http://sofacoustics.org/data/database/thk THK/HRIR_*]: HRTFs of various mannequins provided by the Technische Hochschule Köln (TH Köln, previously Fachhochschule Köln); further details can be found here:
** [https://zenodo.org/record/3928297 Far-field HRTFs]: Gapless data, high spatial resolution HRTFs of Neumann KU 100. Files: HRIR_CIRC360, HRIR_CIRC360RM, HRIR_FULL2DEG, HRIR_L2354, HRIR_L2702.sofa ''(Credit: Benjamin Bernschütz, Germany).''
**[https://zenodo.org/record/4297951 Near-field HRTFs] (HRIR_*_NF*.sofa): High spatial resolution HRTFs of Neumann KU 100 done for various distances ''(Credit: Johannes Arend, Germany)''.
**[https://zenodo.org/record/3928465 Head-gear HRTFs of Neumann KU 100 and HEAD acoustics HMS II] (KU100*.sofa, HMSII*.sofa): High spatial resolution HRTFs while wearing various head gears ''(Credit: Christoph Pörschmann, Germany)''.
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs from SCUT database of the KEMAR (Radius: 0.2 to 1.0 m). ''(Credit: Bosun Xie, China)''
* [http://sofacoustics.org/data/database/tu-berlin TU-Berlin]:
** HRTFs from [http://doi.org/10.5281/zenodo.55418 TU-Berlin of the KEMAR] dummy-head. HRTFs for several distances (>0.5 m). ''(Credit: Hagen Wierstorf, Germany)''
** HRTFs from [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN] dummy-head. Acoustically measured and numerically calculated HRTFs. ''(Credit: Fabian Brinkmann, Germany)''
* [http://sofacoustics.org/data/database/clubfritz Club Fritz]: HRTFs of Neumann KU 100 measured as part of the Club Fritz project where many institutions measured the exact same artificial head, see [http://dx.doi.org/10.1109/JSTSP.2015.2400417 Andreopoulou et al, (2015)]. ''(Credit: Brian Katz, France)''.
* [http://sofacoustics.org/data/database/viking/ VIKING]: Full-sphere HRTFs (.sofa) from the [https://doi.org/10.5281/zenodo.4160401 Viking database]. KEMAR mannequin with 20 different pairs of artificial silicone pinnae attached, plus a "pinna-less" condition, measured for 1513 different directions. 3D scans of left pinnae are also included (.stl). ''(Credit: Simone Spagnol, Denmark)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution%20kemar)/ Aachen: High-resolution HRTFs of the KEMAR] dummy head from the [https://publications.rwth-aachen.de/record/807373 Aachen HRTF database], combined with a 3D model of one subject. ''(Credit: Janina Fels, Aachen)''
* [https://sofacoustics.org/data/database/pku-ioa/ PKU-IOA:] High spatial resolution in-the-ear HRTF database of the KEMAR dummy head with distance from 20 cm to 160 cm, including 20, 30, 40, 50, 75, 100, 130, and 160 cm. ''(Credit: Tianshu Qu, China)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 2 dummy heads (indices D1, D2). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* [http://sofacoustics.org/data/database/axd%20(kemar) AXD]: HRTFs from the [https://www.axdesign.co.uk/tools-and-devices/sonicom-hrtf-dataset AXD/SONICOM database], for the KEMAR head, for 2 ears. ''(Credit: Lorenzo Picinali, London)''
* '''New:''' [http://sofacoustics.org/data/database/AMU AMU]: HRTFs from 4 dummy heads, measured at 2 distances (40cm and 2m). Details can be found [https://hal.science/hal-03521905/document here]. ''(Credit: Adrien Vidal, Marseille)''

===Special HRTFs===
* [http://sofacoustics.org/data/database/ari%20(bte) ARI (BTE)]: Behind-the-ear HRTFs and DTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database].

===PRTFs===
* [http://sofacoustics.org/data/database/widespread Widespread] (Wide dataset of ear shapes and pinna-related transfer functions obtained by random ear drawings): 1005 pinna meshes matched with correspondingly calculated PRTFs from the [https://www.ietr.fr/spip.php?article1618&lang=en FAST team, IETR (CNRS UMR 6164), CentraleSupélec]. The meshes were created by varying principle components obtained from an analysis of 119 pinna meshes of actual listeners. The PRTFs were calculated by means of the boundary-element method for two spatial grids and three distances, see the upcoming publication [http://sofacoustics.org/data/database/widespread/Widespread.pdf (documentation)]. ''(Credit: Corentin Guezenoc, France)''.

== Directivities (sources and receivers) ==

===Sources===

* [http://sofacoustics.org/data/database/tu-berlin%20(directivity)/ TU-Berlin]: One data set of a 3-way loudspeaker (low- mid- and high-unite) in 10°x10° resolution, and two data sets of a trumpet, recorded with a 32 channel microphone array, from the TU Berlin. ''(Credit: David Ackermann, Germany)''

===Receivers===
* TBA

== Room impulse responses [http://sofacoustics.org/data/database databases] (DRIRs, SRIRs, BRIRs) ==

RIRs/BRIRs/DRIRs:
* [http://sofacoustics.org/data/database/oldenburg Oldenburg] DRIRs from [http://medi.uni-oldenburg.de/hrir/html/download.html Oldenburg]. Recordings in an office under several conditions ''(Credit: Stephan Ewert and Daryl Kelvasa, Germany)''.
* [http://sofacoustics.org/data/database/tuburo TuBuRo]: RIRs (from omnidirectional mic) and BRIRs (from KEMAR) recorded with 64-channel loudspeaker array in a room under various absorbing conditions, see [http://dx.doi.org/10.14279/depositonce-87.2 the source], [https://depositonce.tu-berlin.de/bitstream/11303/245.2/11/AdditionalInformation.pdf notes on the file naming] and [https://secure.aes.org/forum/pubs/ebriefs/?elib=17624 Erbes et al. (2015)]. ''(Credit: Vera Erbes, Rostock, Germany)''.
* [http://sofacoustics.org/data/database/sbsbrir SBSBRIR]: BRIRs from the [http://www.bbc.co.uk/rd/publications/sbsbrir Salford-BBC dataset] measured in a recording room for 12 loudspeakers, each for 15 head orientations ([http://usir.salford.ac.uk/30868/ details]). ''(Credit: Chris Pike, Salford)''.
* [http://sofacoustics.org/data/database/thk THK/DRIR_* and THK/BRIR_*]: DRIRs and BRIRs measured at the WDR broadcast studios with various microphone arrays provided by the Technische Hochschule Köln (TH Köln). For description, see [https://zenodo.org/record/3930833 here]. ''(Credit: Johannes Arend)''.
* [https://sofacoustics.org/data/database/room%20transition%20dataset/ Room Transition dataset]: SRIRs capturing the transition between coupled rooms with 101 positions and four coupled room pairs. For description, see [https://doi.org/10.5281/zenodo.4095493 here] ''(Credit: Thomas McKenzie, Aalto)''.
* [https://sofacoustics.org/data/database/6dof%20dataset/ 6DoF dataset]: SRIRs measured in a variable acoustics room with two spherical microphone arrays. For description, see [https://doi.org/10.5281/zenodo.5720723 here]. ''(Credit: Thomas McKenzie, Aalto)''.
* [https://sofacoustics.org/data/database/kaist-iem/ KAIST-IEM dataset]: 6 DoF DRIR dataset measured over a dense loudspeaker grid (6DRIR-DL). For description, see [http://www.aes.org/e-lib/browse.cfm?elib=22184 here]. ''(Credit: Jung-Woo Choi, KAIST, Korea; Franz Zotter, IEM Graz)''.
* [https://sofacoustics.org/data/database/bbc%20maida%20vale/ BBC Maida Vale dataset]: 6 DoF DRIR dataset, measured from the BBC Maida Vale Studios, stored in SH format, available as SingleRoomSRIRs and SingleRoomMIMOSRIRs. For description, see [https://doi.org/10.5281/zenodo.10020866 here]. For full paper, see [https://doi.org/10.3390/acoustics4030047 here]. ''(Credit: Gavin Kearney, University of York)''.
* '''New:''' [https://sofacoustics.org/data/database/tu-ilmenau%20(rooms)/ TU Ilmenau room configurations dataset]: A high spatial resolution dataset of spatial room impulse responses for different acoustic room configurations, available as SingleRoomSRIR. For description, see [https://zenodo.org/records/10450779 here]. ''(Credit: Stephan Werner, Ilmenau)''
* '''New:''' [https://sofacoustics.org/data/database/tu-ilmenau%20(robot)/ TU Ilmenau robot journey dataset]: Spatial room impulse response dataset: A robot's journey through coupled rooms of a reverberant university building, available as SingleRoomSRIR. For description, see [https://zenodo.org/records/10708306 here]. ''(Credit: Stephan Werner, Ilmenau)''
* Tba: [https://sofacoustics.org/data/database/pan-ar/ PAN-AR dataset]: dataset of spatial room impulse responses (SRIRs) measured using a spherical microphone array in 4 distinct rooms with different configurations of source and listener positions. In addition to the SOFA files, spherical pictures, planimetries, and ambient noise recordings are also provided. See the related [https://doi.org/10.1145/3678299.3678332 paper] and the [https://doi.org/10.5281/zenodo.13134270 alternate version of PAN-AR as wav files]. ''(Credit: Giorgio Presti and Davide Fantini, Milan)''

== Headphone impulse responses (HpIRs) ==

* [http://sofacoustics.org/data/headphones/ari ARI]: HpIRs of human listeners from the ARI database. Single headphone, five measurements (with repositioned headphone in-between) for over 100 listeners.
* [http://sofacoustics.org/data/headphones/btdei BT-DEI]: HpIRs of human listeners from the [http://padva.dei.unipd.it/?page_id=345 BT-DEI] database. 16 listeners, three headphones ''(Credit: Michele Geronazzo, Italy)''.
* [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN]: HpIRs of the FABIAN mannequin. Acoustically measured for 34 headphones. ''(Credit: Fabian Brinkmann, Germany)''.

== Example & Test SOFA Files ==

* [http://sofacoustics.org/data/examples/ Example files]: SOFA example & test files for stable [[SOFA_conventions|conventions]]; these files are a subset of other databases on this page, renamed according their conventions.
* [http://sofacoustics.org/data/sofatoolbox_test sofatoolbox_test]: HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA Toolbox v2.x]
* [http://sofacoustics.org/data/sofa_api_mo_test sofa_api_mo_test] (deprecated): HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA API v1.x for Matlab/Octave]

== Other repositories ==

This is a list of other repositories providing HRTFs, BRIRs, and DRIRs available as SOFA files.

* ARI free-field HRTF database. HRTFs available for in-the-ear (ITE) and behind-the-ear (BTE) HRTFs. Link: https://www.oeaw.ac.at/isf/hrtf
* Example files created by the Matlab/Octave API. Link: http://tinyurl.com/sofaHRTFs
* [https://www.york.ac.uk/sadie-project/database.html SADIE]: Far-field HRTFs from the [https://www.york.ac.uk/sadie-project/ SADIE] project of over 20 human listeners. ''(Credit: Gavin Kearney, York)''

== Database missing? ==
If you want your/a SOFA database to be added please [https://www.sofaconventions.org/mediawiki/index.php/People_behind_SOFA contact Michael Mihocic or Piotr Majdak] for support.

SimpleFreeFieldHRIR

2024-04-02T16:49:50Z

Petibub: /* Version 1.0 */

==Description==

This conventions essentially defines the setup used to measure HRTFs in free field. The measured HRTFs are represented as FIR filters, with a single HRTF set of a listener per file. We defined this conventions to describe data from databases like [http://www.kfs.oeaw.ac.at/hrtf ARI], LISTEN, FIU, CIPIC, and others.

In SimpleFreeFieldHRIR version 0.2, we used ListenerRotation to describe the different measurement directions, and the source was assumed to be in the center of the measurement setup. This, however, limited the use of SimpleFreeFieldHRIR, thus, in version 0.4, we use SourcePosition to represent the different HRTF directions. By doing so, more complex data can be described where the tilt of the head is varied, or the listener is not exactly in the center of the measurement setup.

In SimpleFreeFieldHRIR version 0.4, the last version before AES69-2015, we adapted the conventions to SOFA 0.6. The most striking changes are:
* ''Source'' has been renamed to '''Origin''' (in order to reduce the confusion with the object source)
* ''SubjectID'' has been renamed to '''ListenerShortName''' (in order to be more consistent with the general naming of the metadata).

SimpleFreeFieldHRIR version 1.0 represents the current standardized convention set from AES69-2015.

== Version 1.0 ==

[[File:SimpleFreeFieldHRIR-0.3.png|right|thumb|225px]]
This convention set essentially defines the setup used in the [http://www.kfs.oeaw.ac.at/hrtf ARI], LISTEN, FIU, CIPIC, and other similar HRTF databases. The measurements are done in free field with a single excitation source assuming an omnidirectional loudspeaker. Human listeners are considered and thus, the number of receivers is usually two. Note that usually, only the apparent azimuth and elevation angles are provided and this information is modeled as the variation of the source position. This convention set can, however, also be used to describe more complex data where the tilt of the head is varied or the listener is not exactly in the center of the measurement setup. The measured HRTFs are represented as FIR filters, with a single HRTF set of a listener per file.

* General attributes: SOFAConventions: SimpleFreeFieldHRIR, Datatype: FIR, RoomType: free field, other general attributes...

* Listener: The listener is in the origin of the setup, facing in the direction of the y-axis. Thus, for default values, ListenerPosition=[0 0 0], ListenerView=[1 0 0], ListenerUp=[0 0 1], all given in cartesian coordinates.
* Receivers: Per default, two Receivers (=ears) are defined on a head with radius H (in meter, default: 0.09), thus, ReceiverPosition=[0 H 0; 0 -H 0]. Note that any positive integer number of Receivers can be used, though.
* Source: Source consists of a single Emitter only. Per default, EmitterPosition=[0 0 0] in cartesian coordinates. SourcePosition (in spherical coordinates!) varies corresponding to the different azimuth and elevation angles of the measurement directions. Per default, SourcePosition=[0 0 1] (azimuth 0°, elevation 0°, distance 1 m). SourceUp and SourceView are not considered and optional.

{| border="1"
!Name
!Default
![[SOFA_conventions#AnchorFlags|Flags]]
![[SOFA_conventions#AnchorDimensions|Dimensions]]
!Type
!Comment
|-
|GLOBAL:Conventions||<nowiki>SOFA</nowiki>||rm||||attribute||
|-
|GLOBAL:Version||<nowiki>2.1</nowiki>||rm||||attribute||
|-
|GLOBAL:SOFAConventions||<nowiki>SimpleFreeFieldHRIR</nowiki>||rm||||attribute||This convention set is for HRIRs recorded under free-field conditions or other IRs created under conditions where room information is irrelevant
|-
|GLOBAL:SOFAConventionsVersion||<nowiki>1.0</nowiki>||rm||||attribute||
|-
|GLOBAL:APIName||<nowiki></nowiki>||rm||||attribute||
|-
|GLOBAL:APIVersion||<nowiki></nowiki>||rm||||attribute||
|-
|GLOBAL:ApplicationName||<nowiki></nowiki>||||||attribute||
|-
|GLOBAL:ApplicationVersion||<nowiki></nowiki>||||||attribute||
|-
|GLOBAL:AuthorContact||<nowiki></nowiki>||m||||attribute||
|-
|GLOBAL:Comment||<nowiki></nowiki>||||||attribute||
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|GLOBAL:History||<nowiki></nowiki>||||||attribute||
|-
|GLOBAL:License||<nowiki>No license provided, ask the author for permission</nowiki>||m||||attribute||
|-
|GLOBAL:Organization||<nowiki></nowiki>||m||||attribute||
|-
|GLOBAL:References||<nowiki></nowiki>||||||attribute||
|-
|GLOBAL:RoomType||<nowiki>free field</nowiki>||m||||attribute||
|-
|GLOBAL:Origin||<nowiki></nowiki>||||||attribute||
|-
|GLOBAL:DateCreated||<nowiki></nowiki>||m||||attribute||
|-
|GLOBAL:DateModified||<nowiki></nowiki>||m||||attribute||
|-
|GLOBAL:Title||<nowiki></nowiki>||m||||attribute||
|-
|ListenerPosition||<nowiki>[0 0 0] </nowiki>||m||IC, MC||double||
|-
|ListenerPosition:Type||<nowiki>cartesian</nowiki>||m||||attribute||
|-
|ListenerPosition:Units||<nowiki>metre</nowiki>||m||||attribute||
|-
|ReceiverPosition||<nowiki>[0 0.09 0; 0 -0.09 0]</nowiki>||m||rCI, rCM||double||
|-
|ReceiverPosition:Type||<nowiki>cartesian</nowiki>||m||||attribute||
|-
|ReceiverPosition:Units||<nowiki>metre</nowiki>||m||||attribute||
|-
|SourcePosition||<nowiki>[0 0 1]</nowiki>||m||IC, MC||double||Source position is assumed to vary for different directions/positions around the listener
|-
|SourcePosition:Type||<nowiki>spherical</nowiki>||m||||attribute||
|-
|SourcePosition:Units||<nowiki>degree, degree, metre</nowiki>||m||||attribute||
|-
|EmitterPosition||<nowiki>[0 0 0]</nowiki>||m||eCI, eCM||double||
|-
|EmitterPosition:Type||<nowiki>cartesian</nowiki>||m||||attribute||
|-
|EmitterPosition:Units||<nowiki>metre</nowiki>||m||||attribute||
|-
|GLOBAL:DatabaseName||<nowiki></nowiki>||m||||attribute||name of the database to which these data belong
|-
|GLOBAL:ListenerShortName||<nowiki></nowiki>||m||||attribute||ID of the subject from the database
|-
|ListenerUp||<nowiki>[0 0 1]</nowiki>||m||IC, MC||double||
|-
|ListenerView||<nowiki>[1 0 0]</nowiki>||m||IC, MC||double||
|-
|ListenerView:Type||<nowiki>cartesian</nowiki>||m||||attribute||
|-
|ListenerView:Units||<nowiki>metre</nowiki>||m||||attribute||
|-
|Data.IR||<nowiki>[0 0]</nowiki>||m||mRn||double||
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I, M||double||
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||
|-
|Data.Delay||<nowiki>[0 0]</nowiki>||m||IR, MR||double||
|-
|SourceUp||<nowiki>[0 0 1]</nowiki>||||IC, MC||double||
|-
|SourceView||<nowiki>[1 0 0]</nowiki>||||IC, MC||double||
|-
|SourceView:Type||<nowiki>cartesian</nowiki>||||||attribute||
|-
|SourceView:Units||<nowiki>metre</nowiki>||||||attribute||
|}

== Old, deprecated versions ==

For historical reasons the older versions of the SimpleFreeFieldHRIR Convention are listed below.

=== Version 0.4 (deprecated) ===

[[File:SimpleFreeFieldHRIR-0.3.png|right|thumb|225px]]
This conventions essentially defines the setup used in the [http://www.kfs.oeaw.ac.at/hrtf ARI], LISTEN, FIU, CIPIC, and other similar HRTF databases. The measurements are done in free field with a single excitation source assuming an omnidirectional loudspeaker. Human listeners are considered and thus, the number of receivers is two. Note that usually, only the apparent azimuth and elevation angles are provided and this information is modeled as the variation of the source position. This conventions can, however, also be used to describe more complex data where the tilt of the head is varied or the listener is not exactly in the center of the measurement setup. The measured HRTFs are represented as FIR filters, with a single HRTF set of a listener per file.

* General attributes: SOFAConventions: SimpleFreeFieldHRIR, Datatype: FIR, RoomType: free field, other general attributes...

* Listener: The listener is in the origin of the setup, facing in the direction of the y-axis. Thus, for default values, ListenerPosition=[0 0 0], ListenerView=[1 0 0], ListenerUp=[0 0 1], all given in cartesian coordinates.
* Receivers: Two receivers (=ears) on a head with radius H (in meter, default: 0.09): ReceiverPosition=[0 -H 0; 0 +H 0].
* Source: Source consists of a single emitter. For default values, EmitterPosition=[0 0 0] in cartesian coordinates. SourcePosition (in spherical coordinates!) varies corresponding to the different azimuth and elevation angles of the measurement directions. For default, SourcePosition=[0 0 1] (azimuth 0°, elevation 0°, distance 1 m). SourceUp and SourceView are not considered and optional.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:Conventions||SOFA||rm||||attribute||
|-
|GLOBAL:Version||0.6||rm||||attribute||
|-
|GLOBAL:SOFAConventions||SimpleFreeFieldHRIR||rm||||attribute||This convention set is for HRIRs recorded under free-field conditions or other IRs created under conditions where room information is irrelevant
|-
|GLOBAL:SOFAConventionsVersion||0.4||rm||||attribute||
|-
|GLOBAL:APIName||||rm||||attribute||
|-
|GLOBAL:APIVersion||||rm||||attribute||
|-
|GLOBAL:ApplicationName||||||||attribute||
|-
|GLOBAL:ApplicationVersion||||||||attribute||
|-
|GLOBAL:AuthorContact||||m||||attribute||
|-
|GLOBAL:Comment||||||||attribute||
|-
|GLOBAL:DataType||FIR||rm||||attribute||
|-
|GLOBAL:History||||||||attribute||
|-
|GLOBAL:License||No license provided, ask the author for permission||m||||attribute||
|-
|GLOBAL:Organization||||m||||attribute||
|-
|GLOBAL:References||||||||attribute||
|-
|GLOBAL:RoomType||free field||m||||attribute||
|-
|GLOBAL:Origin||||||||attribute||
|-
|GLOBAL:DateCreated||||m||||attribute||
|-
|GLOBAL:DateModified||||m||||attribute||
|-
|GLOBAL:Title||||m||||attribute||
|-
|ListenerPosition||[0 0 0] ||m||IC, MC||double||
|-
|ListenerPosition:Type||cartesian||m||||attribute||
|-
|ListenerPosition:Units||meter||m||||attribute||
|-
|ReceiverPosition||[0 -0.09 0; 0 0.09 0]||m||rCI, rCM||double||
|-
|ReceiverPosition:Type||cartesian||m||||attribute||
|-
|ReceiverPosition:Units||meter||m||||attribute||
|-
|SourcePosition||[0 0 1]||m||IC, MC||double||Source position is assumed to vary for different directions/positions around the listener
|-
|SourcePosition:Type||spherical||m||||attribute||
|-
|SourcePosition:Units||degree, degree, meter||m||||attribute||
|-
|EmitterPosition||[0 0 0]||m||eCI, eCM||double||
|-
|EmitterPosition:Type||cartesian||m||||attribute||
|-
|EmitterPosition:Units||meter||m||||attribute||
|-
|GLOBAL:DatabaseName||||m||||attribute||name of the database to which these data belong
|-
|GLOBAL:ListenerShortName||||m||||attribute||ID of the subject from the database
|-
|ListenerUp||[0 0 1]||m||IC, MC||double||
|-
|ListenerView||[1 0 0]||m||IC, MC||double||
|-
|ListenerView:Type||cartesian||m||||attribute||
|-
|ListenerView:Units||meter||m||||attribute||
|-
|Data.IR||[1 1]||m||mRn||double||
|-
|Data.SamplingRate||48000||m||I||double||
|-
|Data.SamplingRate:Units||hertz||m||||attribute||
|-
|Data.Delay||[0 0]||m||IR, MR||double||
|}

=== Proposed for version 0.3 (deprecated) ===

[[File:SimpleFreeFieldHRIR-0.3.png|right|thumb|225px]]
This conventions essentially defines the setup used in the [http://www.kfs.oeaw.ac.at/hrtf ARI], LISTEN, FIU, CIPIC, and other similar HRTF databases. The measurements are done in free field with a single excitation source assuming an omnidirectional loudspeaker. Human listeners are considered and thus, the number of receivers is two. Note that usually, only the apparent azimuth and elevation angles are provided and this information is modeled as the variation of the source position. This conventions can, however, also be used to describe more complex data where the tilt of the head is varied or the listener is not exactly in the center of the measurement setup. The measured HRTFs are represented as FIR filters, with a single HRTF set of a listener per file.

* General attributes: SOFAConventions: SimpleFreeFieldHRIR, Datatype: FIR, RoomType: free field, other general attributes...

* Listener: The listener is in the origin of the setup, facing in the direction of the y-axis. Thus, for default values, ListenerPosition=[0 0 0], ListenerView=[1 0 0], ListenerUp=[0 0 1], all given in cartesian coordinates.
* Receivers: Two receivers (=ears) on a head with radius H (in meter, default: 0.09): ReceiverPosition=[0 -H 0; 0 +H 0].
* Source: Source consists of a single emitter. For default values, EmitterPosition=[0 0 0] in cartesian coordinates. SourcePosition (in spherical coordinates!) varies corresponding to the different azimuth and elevation angles of the measurement directions. For default, SourcePosition=[0 0 1] (azimuth 0°, elevation 0°, distance 1 m). SourceUp, SourceView, and SourceRotation are not considered and optional.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:Conventions||SOFA||rm||||attribute||
|-
|GLOBAL:Version||0.5||rm||||attribute||
|-
|GLOBAL:SOFAConventions||SimpleFreeFieldHRIR||rm||||attribute||This conventions is for HRIRs recorded under free-field conditions or other IRs created under conditions where room information is irrelevant
|-
|GLOBAL:SOFAConventionsVersion||0.3||rm||||attribute||
|-
|GLOBAL:APIName||||rm||||attribute||
|-
|GLOBAL:APIVersion||||rm||||attribute||
|-
|GLOBAL:ApplicationName||||m||||attribute||
|-
|GLOBAL:ApplicationVersion||||m||||attribute||
|-
|GLOBAL:AuthorContact||||m||||attribute||
|-
|GLOBAL:Comment||||m||||attribute||
|-
|GLOBAL:DataType||FIR||rm||||attribute||
|-
|GLOBAL:History||||m||||attribute||
|-
|GLOBAL:License||No license provided, ask the author for permission||m||||attribute||
|-
|GLOBAL:Organization||||m||||attribute||
|-
|GLOBAL:References||||m||||attribute||
|-
|GLOBAL:RoomType||free field||m||||attribute||
|-
|GLOBAL:Source||||m||||attribute||
|-
|GLOBAL:TimeCreated||||m||||attribute||
|-
|GLOBAL:TimeModified||||m||||attribute||
|-
|GLOBAL:Title||||m||||attribute||
|-
|ListenerPosition||[0 0 0] ||m||IC, MC||double||
|-
|ListenerPosition:Type||cartesian||m||||attribute||
|-
|ListenerPosition:Units||meter||m||||attribute||
|-
|ReceiverPosition||[0 -0.09 0; 0 0.09 0]||m||rCI, rCM||double||
|-
|ReceiverPosition:Type||cartesian||m||||attribute||
|-
|ReceiverPosition:Units||meter||m||||attribute||
|-
|SourcePosition||[0 0 1]||m||IC, MC||double||Source position is assumed to vary for different directions/positions around the listener
|-
|SourcePosition:Type||spherical||m||||attribute||
|-
|SourcePosition:Units||degree, degree, meter||m||||attribute||
|-
|EmitterPosition||[0 0 0]||m||eCI, eCM||double||
|-
|EmitterPosition:Type||cartesian||m||||attribute||
|-
|EmitterPosition:Units||meter||m||||attribute||
|-
|GLOBAL:DatabaseName||||m||||attribute||name of the database to which these data belong
|-
|GLOBAL:SubjectID||||m||||attribute||ID of the subject from the database
|-
|ListenerUp||[0 0 1]||m||IC, MC||double||
|-
|ListenerView||[1 0 0]||m||IC, MC||double||
|-
|Data.IR||[1 1]||m||mRn||double||
|-
|Data.SamplingRate||48000||m||I||double||
|-
|Data.SamplingRate:Units||hertz||m||||attribute||
|-
|Data.Delay||[0 0]||m||IR, MR||double||
|}

=== Version 0.2 (deprecated) ===

[[File:SimpleFreeFieldHRIR-0.2.png|right|thumb|225px]]
This conventions essentially defines the setup used in the [http://www.kfs.oeaw.ac.at/hrtf ARI], LISTEN, FIU, CIPIC, and other similar HRTF databases. The measurements are done in free field with a single excitation source assuming an omnidirectional loudspeaker. Human listeners are considered and thus, the number of receivers is two. Azimuth and elevation angles are varied and the tilt of the head is not considered during the measurement. The measured HRTFs are represented as FIR filters, with a single HRTF set of a listener per file.

* General attributes: SOFAConventions: SimpleFreeFieldHRIR, Datatype: FIR, RoomType: free field, other general attributes...
* Source: Source is in the origin of the setup and consists of a single emitter. For default values, SourcePosition: (0 0 0), and EmitterPosition: (0 0 0). SourceUp, SourceView, and SourceRotation are not considered and optional.
* Listener: The listener is in the measurement distance X (in meter) from the source, facing the source. For default values, we consider a single distance X, thus, ListenerPosition: (X 0 0), ListenerView: (0 0 0), ListenerUp: (X 0 1).
* Receivers: Two receivers (=ears) on a head with radius H (in meter): ReceiverPosition: (0 -H 0; 0 +H 0).
* The different azimuth and elevation angles of the measurement are described by the ListenerRotation as [M 3] matrix (in degrees). The coordinate type is [http://en.wikipedia.org/wiki/Axes_conventions DIN 9300].

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL_Conventions||SOFA||rm||||||
|-
|GLOBAL_Version||0.4||rm||||||
|-
|GLOBAL_SOFAConventions||SimpleFreeFieldHRIR||rm||||||
|-
|GLOBAL_SOFAConventionsVersion||0.2||rm||||||
|-
|GLOBAL_APIName||||rm||||||Insert the API Name here
|-
|GLOBAL_APIVersion||||rm||||||Insert the API Version here
|-
|GLOBAL_AuthorContact||||m||||||
|-
|GLOBAL_License||No license provided, ask the author for permission||m||||||
|-
|GLOBAL_Organization||||m||||||
|-
|GLOBAL_RoomType||free field||m||||||
|-
|GLOBAL_DataType||FIR||rm||||||
|-
|GLOBAL_History||||m||||||
|-
|GLOBAL_Source||||m||||||
|-
|GLOBAL_Title||||m||||||
|-
|GLOBAL_References||||m||||||
|-
|GLOBAL_Comment||||m||||||
|-
|GLOBAL_TimeCreated||||m||||||will be updated when saving and not existing or empty
|-
|GLOBAL_TimeModified||||m||||||will be updated each time when saving
|-
|GLOBAL_ApplicationName||||m||||||
|-
|GLOBAL_ApplicationVersion||||m||||||
|-
|GLOBAL_DatabaseName||||m||||||
|-
|GLOBAL_SubjectID||||m||||||
|-
|ListenerPosition||[1 0 0] ||m||IC, MC||double||
|-
|ListenerPosition_Type||cartesian||m||||||
|-
|ListenerPosition_Units||meter||m||||||
|-
|ListenerUp||[0 0 1]||m||IC, MC||double||
|-
|ListenerView||[-1 0 0]||m||IC, MC||double||
|-
|ListenerRotation||[0 0 0]||m||IC, MC||double||
|-
|ListenerRotation_Type||din9300||m||||||
|-
|ListenerRotation_Units||degrees||m||||||
|-
|ReceiverPosition||[0 -0.09 0; 0 0.09 0]||m||rCI, rCM||double||
|-
|ReceiverPosition_Type||cartesian||m||||||
|-
|ReceiverPosition_Units||meter||m||||||
|-
|SourcePosition||[0 0 0]||m||IC, MC||double||
|-
|SourcePosition_Type||cartesian||m||||||
|-
|SourcePosition_Units||meter||m||||||
|-
|EmitterPosition||[0 0 0]||m||eCI, eCM||double||
|-
|EmitterPosition_Type||cartesian||m||||||
|-
|EmitterPosition_Units||meter||m||||||
|-
|Data.IR||[1 1]||m||mRn||double||
|-
|Data.SamplingRate||48000||m||I||double||
|-
|Data.SamplingRate_Units||hertz||m||||||
|-
|Data.Delay||[0 0]||m||IR, MR||double||
|}

=== Version 0.1 (deprecated) ===
{| border="1"
!Name
!Default
!Flags
!Dimensions
!Comment
|-
|GLOBAL_Conventions||SOFA||rm|| ||
|-
|GLOBAL_Version||0.3||rm|| ||
|-
|GLOBAL_SOFAConventions||SimpleFreeFieldHRIR||rm ||||
|-
|GLOBAL_SOFAConventionsVersion||0.1||m|| ||
|-
|GLOBAL_APIName||*||rm|| ||Insert the API Name here
|-
|GLOBAL_APIVersion||*||rm || ||Insert the API Version here
|-
|GLOBAL_ApplicationName||||m ||||
|-
|GLOBAL_ApplicationVersion||||m ||||
|-
|GLOBAL_AuthorContact||||m ||||
|-
|GLOBAL_License||No license provided, ask the author for permission||m||||
|-
|GLOBAL_Organization||||m ||||
|-
|GLOBAL_DatabaseName||||m||||
|-
|GLOBAL_SubjectID||||m ||||
|-
|GLOBAL_RoomType||free field||m||||
|-
|GLOBAL_DataType||FIR||m||||
|-
|GLOBAL_History||||||||
|-
|GLOBAL_Comment||||||||
|-
|GLOBAL_DatabaseTimeCreated||*||m|||| will be updated when saving and not existing or empty
|-
|GLOBAL_DatabaseTimeModified||*||m ||||will be updated each time when saving
|-
|I||1||rm||I||
|-
|I_LongName||singleton dimension||rm|| ||
|-
|R||2||rm||R||
|-
|R_LongName||number of receivers||rm||||
|-
|E||1||rm||E||
|-
|E_LongName||number of emitters||rm||||
|-
|N|| - ||m||N||
|-
|N_LongName||time||m|| ||
|-
|N_Units||samples||m|| ||
|-
|M|| - ||m||M||
|-
|M_LongName||number of measurements||rm ||||
|-
|C||3||rm||C||
|-
|C_LongName||coordinate triplet||rm||||
|-
|ListenerPosition|| [1 0 0] ||m||IC, MC||
|-
|ListenerPosition_Type||cartesian||m|| ||
|-
|ListenerPosition_Unitsmeter||||m||||
|-
|ListenerUp||[1.2 0 1]||m||IC, MC||
|-
|ListenerUp_Type||cartesian||m||||
|-
|ListenerUp_Units||meter||m||||
|-
|ListenerView||[0 0 0]||m||IC, MC||
|-
|ListenerView_Type||cartesian||m||||
|-
|ListenerView_Units||meter||m||||
|-
|ListenerRotation||[0 0 0]||m||IC, MC||
|-
|-
|ListenerRotation_Type||din9300||m||||
|-
|ListenerRotation_Units||degrees||m ||||
|-
|ReceiverPosition||[0 -0.09 0; 0 0.09 0]||m||rCI, rCM||
|-
|ReceiverPosition_Type||cartesian||m||||
|-
|ReceiverPosition_Units||meter||m ||||
|-
|SourcePosition||[0 0 0]||m||IC, MC||
|-
|SourcePosition_Type||cartesian||m||||
|-
|SourcePosition_Units||meter||m ||||
|-
|SourceUp||[0 0 1]||m||IC, MC||
|-
|SourceUp_Type||cartesian||m||||
|-
|SourceUp_Units||meter||m||||
|-
|SourceView||[1 0 0]||m||IC, MC||
|-
|SourceView_Type||cartesian||m||||
|-
|SourceView_Units||meter||m||||
|-
|EmitterPosition||[0 0 0]||m||eCI, eCM||
|-
|EmitterPosition_Type||cartesian||m||||
|-
|EmitterPosition_Units||meter||m ||||
|-
|Data.IR||[1 1]||m||mRn||
|-
|Data.SamplingRate||48000||m||I||
|-
|Data.SamplingRate_Units||hertz||m||||
|}

SOFA conventions

2023-09-12T18:02:56Z

Petibub: /* Proposed SOFA conventions */

SOFA conventions specify the description of data and metadata for a particular kind of measured data.

This is important in order to meet the different requirements coming from different application fields, specified. For example, description of HRTFs, BRIRs, and DRIRs requires different metadata. Also, some applications may prefer to see the data stored in a different way. These conventions, once approved by the peer group are defined in SOFA conventions.

Specification of conventions are displayed in tables using the following legend:

* '''Name''': the name of the metadata
** A colon: the metadata is an attribute
*** "GLOBAL:": the metadata is a global attribute
*** "X:Y": the metadata is an attribute Y of the variable X
** No colon: the metadata is a variable
** Data.X: the metadata is structured within the data
* '''Default''': default value for the metadata
** An asterisk (*): special handling required, mentioned in the column Comment
* <div id="AnchorFlags">'''Flags''':</div>
** r: read-only, must be the default value
** m: mandatory, must be saved in the file
* <div id="AnchorDimensions">'''Dimensions''': dimensions of the metadata
** lower case: the variable size in that dimension determines the dimension size in the file
** upper case: variable must be of that dimension (or one of these dimensions)
: Expand the following table to see the dimensions used in SOFA. Depending on the conventions there might be further restrictions. See [[SOFA specifications]] for more explanations.
: {| class="mw-collapsible mw-collapsed wikitable"
!Dimension
!Description
!Restrictions
|-
|M
|number of measurements
|integer >0
|-
|R
|number of receivers or harmonic coefficients describing receivers
|integer >0
|-
|E
|number of emitters or harmonic coefficients describing emitters
|integer >0
|-
|N
|number of data samples describing one measurement
|integer >0
|-
|S
|number of characters in a string
|integer ≥0
|-
|style="color:gray" |I
|style="color:gray" |singleton dimension, constant
|style="color:gray" |always 1
|-
|style="color:gray" |C
|style="color:gray" |coordinate triplet, constant
|style="color:gray" |always 3
|}

== Standardized SOFA conventions ==

Standardized SOFA conventions are those which have been standardized by the AES.

As with AES69-2022 (SOFA 2.1), we standardized the following conventions:
* [[GeneralFIR]]: General convention with FIR as DataType (no restrictions but DataType)
* [[GeneralTF]]: General convention with TF as DataType (no restrictions but DataType)
* [[SimpleFreeFieldHRIR]]: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.
* [[GeneralFIR-E]]: General convention with FIR-E as DataType (no restrictions but DataType). GeneralFIR-E is the standardized version of the previously proposed GeneralFIR convention. It extends GeneralFIR by having Emitter as an explicit dimension in the data.
* [[GeneralTF-E]]: General convention with TF-E as DataType (no restrictions but DataType). GeneralTF-E extends GeneralTF by having Emitter as an explicit dimension in the data.
* [[GeneralSOS]]: General convention following [[GeneralFIR]] with SOS as DataType.
* [[General]]: General convention with any datatype (no restrictions at all).
* [[SimpleFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is TF.
* [[SimpleFreeFieldHRSOS]]: Free-field HRTFs stored as second-order sections, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is SOS.
* [[FreeFieldHRTF]]: Free-field HRTFs stored as transfer functions in the spherical-harmonics domain, measured with an omnidirectional source for a single listener. Based on [[SimpleFreeFieldHRTF]], the only difference is that the HRTFs are in a spatially continuous representation.
* [[FreeFieldHRIR]]: An extension of [[SimpleFreeFieldHRIR]] in order to consider more complex data sets described in spatially continuous representation. Each HRTF direction corresponds to an emitter, and a consistent measurement for a single listener and all directions is described by a set of the emitter positions surrounding the listener.
* [[FreeFieldDirectivityTF]]: Convention for storing directivities of musical instruments or loudspeakers at spatial discrete points in the frequency domain. FreeFieldDirectivityTF is the standardized version of the previously proposed (Simple)FreeFieldDirectivityTF and MusicalInstrumentDirectivityTF.
* [[SingleRoomSRIR]]: spatial room impulse responses (SRIRs) measured with an arbitrary number of receivers (R>1, such as a microphone array) and an omnidirectional source (E=1) in a single room. SingleRoomSRIR is the standardized version of the previously proposed [[SingleRoomDRIR]].
* [[SingleRoomMIMOSRIR]]: SRIRs measured with a compact listener containing an arbitrary number of receivers (R>1, such as a compact microphone array) and a compact source containing an arbitrary number of emitters (E>1, such as a multi-emitter loudspeaker) for multiple positions and/or orientations of the listener and/or source, in a single room.
* [[SimpleHeadphoneIR]]: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.

Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.

==Stable SOFA conventions==
Stable SOFA conventions are those for which SOFA files are publicly available, have been checked by the SOFA team for consistency, and can be read/modified by at least one publicly available software package. They have version of 1.0 at least.

These conventions, when used often and widely, can be proposed for standardization to the AES.

==Proposed SOFA conventions==

Proposed SOFA conventions are those being currently discussed and considered as work in progress. They have a version 0.x.

Currently available proposed conventions:
* [[GeneralString]]: Conventions for testing the string support.
* [[AnnotatedReceiverAudio]]: Conventions to store (binaural) audio data at the receivers, annotated with geometric information.
* [[AnnotatedEmitterAudio]]: Conventions to store audio data at the ermitters, annotated with geometric information.

If you would like to propose a new convention, consider the following rules:
* Data must exist or are being developed
* Data can not be described by existing SOFA conventions
* Relevant information about the data available

== Ideas for future conventions ==

Here we list the suggestions and feedback from the peer group:
* Include anthropometric data
* Crosstalk cancellation filters
* Include calibration data from the measurement
* Include room pictures

Please use the "Discussion" function to discuss these topics.

==Deprecated SOFA conventions==

These conventions are deprecated because their proposal has changed or they have been standardized under different name. They are listed here for the sake of completeness only. When reading a SOFA file with a deprecated convention, convert to that stated below:
* [[MusicalInstrumentDirectivityTF]]: use [[FreeFieldDirectivityTF]] instead.
* SimpleFreeFieldDirectivityTF: use [[FreeFieldDirectivityTF]] instead.
* [[SimpleBRIR]]: use [[SingleRoomSRIR]] instead.
* [[GeneralFIRE]]: use [[GeneralFIR-E]] instead.
* [[SimpleFreeFieldTF]]: use [[SimpleFreeFieldHRTF]] instead.
* [[SimpleFreeFieldSOS]]: use [[SimpleFreeFieldHRSOS]] instead.
* [[SingleRoomDRIR]]: use [[SingleRoomSRIR]] instead.
* [[MultiSpeakerBRIR]]: use [[SingleRoomMIMOSRIR]] instead.
* [[SingleTrackedAudio]]: Conventions to record audio data annotated with geometric information. Deprecated: Please use [[AnnotatedReceiverAudio]] or [[AnnotatedEmitterAudio]] instead.

We strongly discourage from saving data with those conventions.

== Feedback and Contribution ==

If you would like to contribute or propose new SOFA conventions:
* Send an e-mail to the [mailto:sofacoustics-devel@lists.sourceforge.net mailing list]. You don't have to be a member of the mailing list to send a message to the moderator.
* Go to one of the SOFA pages of your interest and use the "Discussion" for your contribution.
We appreciate your feedback!

SOFA conventions

2023-09-12T18:01:30Z

Petibub: /* Stable SOFA conventions */

SOFA conventions specify the description of data and metadata for a particular kind of measured data.

This is important in order to meet the different requirements coming from different application fields, specified. For example, description of HRTFs, BRIRs, and DRIRs requires different metadata. Also, some applications may prefer to see the data stored in a different way. These conventions, once approved by the peer group are defined in SOFA conventions.

Specification of conventions are displayed in tables using the following legend:

* '''Name''': the name of the metadata
** A colon: the metadata is an attribute
*** "GLOBAL:": the metadata is a global attribute
*** "X:Y": the metadata is an attribute Y of the variable X
** No colon: the metadata is a variable
** Data.X: the metadata is structured within the data
* '''Default''': default value for the metadata
** An asterisk (*): special handling required, mentioned in the column Comment
* <div id="AnchorFlags">'''Flags''':</div>
** r: read-only, must be the default value
** m: mandatory, must be saved in the file
* <div id="AnchorDimensions">'''Dimensions''': dimensions of the metadata
** lower case: the variable size in that dimension determines the dimension size in the file
** upper case: variable must be of that dimension (or one of these dimensions)
: Expand the following table to see the dimensions used in SOFA. Depending on the conventions there might be further restrictions. See [[SOFA specifications]] for more explanations.
: {| class="mw-collapsible mw-collapsed wikitable"
!Dimension
!Description
!Restrictions
|-
|M
|number of measurements
|integer >0
|-
|R
|number of receivers or harmonic coefficients describing receivers
|integer >0
|-
|E
|number of emitters or harmonic coefficients describing emitters
|integer >0
|-
|N
|number of data samples describing one measurement
|integer >0
|-
|S
|number of characters in a string
|integer ≥0
|-
|style="color:gray" |I
|style="color:gray" |singleton dimension, constant
|style="color:gray" |always 1
|-
|style="color:gray" |C
|style="color:gray" |coordinate triplet, constant
|style="color:gray" |always 3
|}

== Standardized SOFA conventions ==

Standardized SOFA conventions are those which have been standardized by the AES.

As with AES69-2022 (SOFA 2.1), we standardized the following conventions:
* [[GeneralFIR]]: General convention with FIR as DataType (no restrictions but DataType)
* [[GeneralTF]]: General convention with TF as DataType (no restrictions but DataType)
* [[SimpleFreeFieldHRIR]]: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.
* [[GeneralFIR-E]]: General convention with FIR-E as DataType (no restrictions but DataType). GeneralFIR-E is the standardized version of the previously proposed GeneralFIR convention. It extends GeneralFIR by having Emitter as an explicit dimension in the data.
* [[GeneralTF-E]]: General convention with TF-E as DataType (no restrictions but DataType). GeneralTF-E extends GeneralTF by having Emitter as an explicit dimension in the data.
* [[GeneralSOS]]: General convention following [[GeneralFIR]] with SOS as DataType.
* [[General]]: General convention with any datatype (no restrictions at all).
* [[SimpleFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is TF.
* [[SimpleFreeFieldHRSOS]]: Free-field HRTFs stored as second-order sections, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is SOS.
* [[FreeFieldHRTF]]: Free-field HRTFs stored as transfer functions in the spherical-harmonics domain, measured with an omnidirectional source for a single listener. Based on [[SimpleFreeFieldHRTF]], the only difference is that the HRTFs are in a spatially continuous representation.
* [[FreeFieldHRIR]]: An extension of [[SimpleFreeFieldHRIR]] in order to consider more complex data sets described in spatially continuous representation. Each HRTF direction corresponds to an emitter, and a consistent measurement for a single listener and all directions is described by a set of the emitter positions surrounding the listener.
* [[FreeFieldDirectivityTF]]: Convention for storing directivities of musical instruments or loudspeakers at spatial discrete points in the frequency domain. FreeFieldDirectivityTF is the standardized version of the previously proposed (Simple)FreeFieldDirectivityTF and MusicalInstrumentDirectivityTF.
* [[SingleRoomSRIR]]: spatial room impulse responses (SRIRs) measured with an arbitrary number of receivers (R>1, such as a microphone array) and an omnidirectional source (E=1) in a single room. SingleRoomSRIR is the standardized version of the previously proposed [[SingleRoomDRIR]].
* [[SingleRoomMIMOSRIR]]: SRIRs measured with a compact listener containing an arbitrary number of receivers (R>1, such as a compact microphone array) and a compact source containing an arbitrary number of emitters (E>1, such as a multi-emitter loudspeaker) for multiple positions and/or orientations of the listener and/or source, in a single room.
* [[SimpleHeadphoneIR]]: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.

Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.

==Stable SOFA conventions==
Stable SOFA conventions are those for which SOFA files are publicly available, have been checked by the SOFA team for consistency, and can be read/modified by at least one publicly available software package. They have version of 1.0 at least.

These conventions, when used often and widely, can be proposed for standardization to the AES.

==Proposed SOFA conventions==

Proposed SOFA conventions are those being currently discussed and considered as work in progress. If you would like to propose a new convention, consider the following rules:
* Data must exist (do not foresee the future)
* Data can not be described by existing SOFA conventions
* Relevant information about the data available

Currently available proposed conventions:
* [[AnnotatedEmitterAudio]]: Conventions to store audio data at the ermitters, annotated with geometric information.

== Ideas for future conventions ==

Here we list the suggestions and feedback from the peer group:
* Include anthropometric data
* Crosstalk cancellation filters
* Include calibration data from the measurement
* Include room pictures

Please use the "Discussion" function to discuss these topics.

==Deprecated SOFA conventions==

These conventions are deprecated because their proposal has changed or they have been standardized under different name. They are listed here for the sake of completeness only. When reading a SOFA file with a deprecated convention, convert to that stated below:
* [[MusicalInstrumentDirectivityTF]]: use [[FreeFieldDirectivityTF]] instead.
* SimpleFreeFieldDirectivityTF: use [[FreeFieldDirectivityTF]] instead.
* [[SimpleBRIR]]: use [[SingleRoomSRIR]] instead.
* [[GeneralFIRE]]: use [[GeneralFIR-E]] instead.
* [[SimpleFreeFieldTF]]: use [[SimpleFreeFieldHRTF]] instead.
* [[SimpleFreeFieldSOS]]: use [[SimpleFreeFieldHRSOS]] instead.
* [[SingleRoomDRIR]]: use [[SingleRoomSRIR]] instead.
* [[MultiSpeakerBRIR]]: use [[SingleRoomMIMOSRIR]] instead.
* [[SingleTrackedAudio]]: Conventions to record audio data annotated with geometric information. Deprecated: Please use [[AnnotatedReceiverAudio]] or [[AnnotatedEmitterAudio]] instead.

We strongly discourage from saving data with those conventions.

== Feedback and Contribution ==

If you would like to contribute or propose new SOFA conventions:
* Send an e-mail to the [mailto:sofacoustics-devel@lists.sourceforge.net mailing list]. You don't have to be a member of the mailing list to send a message to the moderator.
* Go to one of the SOFA pages of your interest and use the "Discussion" for your contribution.
We appreciate your feedback!

User talk:JonnieStueferTest202303

2023-03-21T08:53:11Z

Petibub: Welcome!

User:JonnieStueferTest202303

2023-03-21T08:53:11Z

Petibub: Creating user page for new user.

Hi Michael! I'm just testing the account registration feature.

User talk:Boluomemg

2023-02-17T18:22:49Z

Petibub: Welcome!

User:Boluomemg

2023-02-17T18:22:48Z

Petibub: Creating user page for new user.

A Video&Audio programmer.
Write video player
(
support iOS/Android/Windows/Mac;
support HDR/Space Audio).

User talk:Jingyi Guo

2022-07-25T12:50:47Z

Petibub: Welcome!

User:Jingyi Guo

2022-07-25T12:50:47Z

Petibub: Creating user page for new user.

Communication University of China，Recording Art of Grade 2019 (Recording Engineering)

Files

2022-07-18T12:10:35Z

Petibub: /* General purpose free-field databases (HRTFs, PRTFs) */

The [http://sofacoustics.org/data main SOFA repository] aims at collect the worldwide available HRTFs, BRIRs, DRIRs, and other SOFA-related data at a single place. It is just in the process of being created: Partial download, metadata access, and database search is not available (yet, we are investigating the possibility of using [http://www.opendap.org/ OPeNDAP] for SOFA repositories). Currently, the data can be accessed and downloaded as they are and the metadata are provided in the particular files.

== General purpose free-field [http://sofacoustics.org/data/database databases] (HRTFs, PRTFs) ==

Standard (in-the-ear canal) HRTFs of humans:
* [http://sofacoustics.org/data/database/ari ARI]: HRTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database]. In-the-ear HRTFs and DTFs for over 220 listeners.
** hrtf, dtf: HRTFs and DTFs, respectively, equalized between 300 Hz and 18 kHz
** hrtf b/c, dtf b/c: HRTFs and DTFs, equalized between 50 Hz and 18 kHz for hi-fi auralizations ("b" and "c" differ each other only in their starting positions and the order of measurement positions: b: 0°→0°, c: 270°→270°; direction always clockwise ↻)
* [http://sofacoustics.org/data/database/ari%20(altb) ARI (ALTB)]: HRTFs from the ARI database. Measurements for some of the listeners from the ARI database, repeated and evaluated a few years later, see [http://www.researchgate.net/publication/236111930_Sound_localization_in_individualized_and_non-individualized_crosstalk_cancellation_systems Majdak et al. (2013)].
* [http://sofacoustics.org/data/database/cipic CIPIC]: HRTFs from the [https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/ CIPIC database]. 45 listeners, partially [https://sofacoustics.org/data/database/cipic/anthropometry.zip anthropometric data] available.
* [http://sofacoustics.org/data/database/riec RIEC]: Far-field HRTFs from the [http://www.riec.tohoku.ac.jp/pub/hrtf/index.html RIEC] database from the Advanced Acoustic Information Systems Laboratory, Research Institute of Electrical Communication, Tohoku University, Japan of over 100 human listeners. ''(Credit: Kajni Watanabe, Japan)''
* [http://sofacoustics.org/data/database/aachen Aachen]: HRTFs from the [http://www.akustik.rwth-aachen.de/go/id/lsly Aachen HRTF database], combined with anthropometric data and 3D ear models of 48 listeners. See the [http://gershwin.akustik.rwth-aachen.de/hrtf/hrtf-lic.php license]. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution)/ Aachen: High-resolution HRTFs] from the [https://publications.rwth-aachen.de/record/793261 Aachen HRTF database], combined with a [https://publications.rwth-aachen.de/record/793260 3D model] of one human listener. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/hutubs/ HUTUBS]: HRTFs from the [https://dx.doi.org/10.14279/depositonce-8487 HUTUBS] database containing anthropometric data, headphone impulse responses, and 3D head models from 96 listeners. The database acquisition is detailed in the accompanying [https://doi.org/10.17743/jaes.2019.0024 paper]. ''(Credit: Fabian Brinkmann, Berlin)''
* [http://sofacoustics.org/data/database/chedar/ CHEDAR]: Numerically calculated HRTFs (.sofa) with 3D meshes of the head and pinnae (.ply) and anthropometric data (.mat) provided. For more details, see the [http://sofacoustics.org/data/database/chedar/documentation.pdf documentation]. ''(Credit: Slim Ghorbal, France)''
* [https://sofacoustics.org/data/database/3d3a/ 3D3A]: Measured in-the-ear HRTFs (.sofa) of 38 subjects, and 3D head and torso scans of 31 subjects from the [http://www.princeton.edu/3D3A/HRTFMeasurements.html Princeton 3D3A Database]. ''(Credit: Edgar Choueiri, USA)''
* [https://sofacoustics.org/data/database/bili%20(dtf)/ BiLi]: Measured in-the-ear HRTF files (.sofa) of 56 subjects. Data are available in [https://sofacoustics.org/data/database/bili%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/bili%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/bili%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/crossmod%20(dtf)/ Crossmod]: Measured in-the-ear HRTF files (.sofa) of 24 subjects. Data are available in [https://sofacoustics.org/data/database/crossmod%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/crossmod%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/crossmod%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ Listen]: Measured in-the-ear HRTF files (.sofa) of 50 subjects. Data are available in [https://sofacoustics.org/data/database/listen%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/listen%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/listen%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/sadie/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 18 human subjects (indices H3 to H20). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* '''New: [http://sofacoustics.org/data/database/scut SCUT]''': Near-field HRTFs and anthropometric data ([https://sofacoustics.org/data/database/scut/AnthropometricParameters.csv CSV] and [https://sofacoustics.org/data/database/scut/AnthropometricParameters.pdf PDF]) of human listeners. ''(Credit: Guangzheng Yu & Yu Lan, China)''

HRTFs of artificial heads:
* [http://sofacoustics.org/data/database/mit MIT-KEMAR]: HRTFs from [http://sound.media.mit.edu/resources/KEMAR/ MIT of the KEMAR] dummy head. Reference HRTFs used in many publications.
* [http://sofacoustics.org/data/database/ari%20(artificial) ARI (ARTIFICIAL)]: HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners:
** NH169: HRTFs, DTFs, and raw data of a printed head of the corresponding human listener
** NH172: HRTFs, DTFs, raw and reference data of the dummy head Neumann KU 100. Also part of Club Fritz, see below.
* [http://sofacoustics.org/data/database/thk THK/HRIR_*]: HRTFs of various mannequins provided by the Technische Hochschule Köln (TH Köln, previously Fachhochschule Köln); further details can be found here:
** [https://zenodo.org/record/3928297 Far-field HRTFs]: Gapless data, high spatial resolution HRTFs of Neumann KU100. Files: HRIR_CIRC360, HRIR_CIRC360RM, HRIR_FULL2DEG, HRIR_L2354, HRIR_L2702.sofa ''(Credit: Benjamin Bernschütz, Germany).''
**[https://zenodo.org/record/4297951 Near-field HRTFs] (HRIR_*_NF*.sofa): High spatial resolution HRTFs of Neumann KU100 done for various distances ''(Credit: Johannes Arend, Germany)''.
**[https://zenodo.org/record/3928465 Head-gear HRTFs of Neumann KU100 and HEAD acoustics HMS II] (KU100*.sofa, HMSII*.sofa): High spatial resolution HRTFs while wearing various head gears ''(Credit: Christoph Pörschmann, Germany)''.
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs from SCUT database of the KEMAR (Radius: 0.2 to 1.0 m). ''(Credit: Bosun Xie, China)''
* [http://sofacoustics.org/data/database/tu-berlin TU-Berlin]:
** HRTFs from [http://doi.org/10.5281/zenodo.55418 TU-Berlin of the KEMAR] dummy-head. HRTFs for several distances (>0.5 m). ''(Credit: Hagen Wierstorf, Germany)''
** HRTFs from [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN] dummy-head. Acoustically measured and numerically calculated HRTFs. ''(Credit: Fabian Brinkmann, Germany)''
* [http://sofacoustics.org/data/database/clubfritz Club Fritz]: HRTFs of Neumann KU 100 measured as part of the Club Fritz project where many institutions measured the exact same artificial head, see [http://dx.doi.org/10.1109/JSTSP.2015.2400417 Andreopoulou et al, (2015)]. ''(Credit: Brian Katz, France)''.
* [http://sofacoustics.org/data/database/viking/ VIKING]: Full-sphere HRTFs (.sofa) from the [https://doi.org/10.5281/zenodo.4160401 Viking database]. KEMAR mannequin with 20 different pairs of artificial silicone pinnae attached, plus a "pinna-less" condition, measured for 1513 different directions. 3D scans of left pinnae are also included (.stl). ''(Credit: Simone Spagnol, Denmark)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution%20kemar)/ Aachen: High-resolution HRTFs of the KEMAR] dummy head from the [https://publications.rwth-aachen.de/record/807373 Aachen HRTF database], combined with a 3D model of one subject. ''(Credit: Janina Fels, Aachen)''
* [https://sofacoustics.org/data/database/pku-ioa/ PKU-IOA:] High spatial resolution in-the-ear HRTF database of the KEMAR dummy head with distance from 20 cm to 160 cm, including 20, 30, 40, 50, 75, 100, 130, and 160 cm. ''(Credit: Tianshu Qu, China)''
* '''New: [https://sofacoustics.org/data/database/listen%20(dtf)/ SADIE]''': Measured in-the-ear HRTF files (.sofa) of 2 dummy heads (indices D1, D2). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''

Special HRTFs:
* [http://sofacoustics.org/data/database/ari%20(bte) ARI (BTE)]: Behind-the-ear HRTFs and DTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database].

PRTFs:
* [http://sofacoustics.org/data/database/widespread Widespread] (Wide dataset of ear shapes and pinna-related transfer functions obtained by random ear drawings): 1005 pinna meshes matched with correspondingly calculated PRTFs from the [https://www.ietr.fr/spip.php?article1618&lang=en FAST team, IETR (CNRS UMR 6164), CentraleSupélec]. The meshes were created by varying principle components obtained from an analysis of 119 pinna meshes of actual listeners. The PRTFs were calculated by means of the boundary-element method for two spatial grids and three distances, see the upcoming publication [http://sofacoustics.org/data/database/widespread/Widespread.pdf (documentation)]. ''(Credit: Corentin Guezenoc, France)''.

== Directivities (sources and receivers) ==

'''Sources''':

* [http://sofacoustics.org/data/database/tu-berlin%20(directivity)/ TU-Berlin]: One data set of a 3-way loudspeaker (low- mid- und high-unite) in 10°x10° resolution, and two data sets of a trumpet, recorded with a 32 channel microphone array, from the TU Berlin. ''(Credit: David Ackermann, Germany)''

'''Receivers''':
* TBA

== Room impulse responses [http://sofacoustics.org/data/database databases] (DRIRs, SRIRs, BRIRs) ==

RIRs/BRIRs/DRIRs:
* [http://sofacoustics.org/data/database/oldenburg Oldenburg] DRIRs from [http://medi.uni-oldenburg.de/hrir/html/download.html Oldenburg]. Recordings in an office under several conditions ''(Credit: Stephan Ewert and Daryl Kelvasa, Germany)''.
* [http://sofacoustics.org/data/database/tuburo TuBuRo]: RIRs (from omnidirectional mic) and BRIRs (from KEMAR) recorded with 64-channel loudspeaker array in a room under various absorbing conditions, see [http://dx.doi.org/10.14279/depositonce-87.2 the source], [https://depositonce.tu-berlin.de/bitstream/11303/245.2/11/AdditionalInformation.pdf notes on the file naming] and [https://secure.aes.org/forum/pubs/ebriefs/?elib=17624 Erbes et al. (2015)]. ''(Credit: Vera Erbes, Rostock, Germany)''.
* [http://sofacoustics.org/data/database/sbsbrir SBSBRIR]: BRIRs from the [http://www.bbc.co.uk/rd/publications/sbsbrir Salford-BBC dataset] measured in a recording room for 12 loudspeakers, each for 15 head orientations ([http://usir.salford.ac.uk/30868/ details]). ''(Credit: Chris Pike, Salford)''.
* [http://sofacoustics.org/data/database/thk THK/DRIR_* and THK/BRIR_*]: DRIRs and BRIRs measured at the WDR broadcast studios with various microphone arrays provided by the Technische Hochschule Köln (TH Köln). For description, see [https://zenodo.org/record/3930833 here]. ''(Credit: Johannes Arend)''.
*'''New: [https://sofacoustics.org/data/database/room%20transition%20dataset/ Room Transition dataset]''': SRIRs capturing the transition between coupled rooms with 101 positions and four coupled room pairs. For description, see [https://doi.org/10.5281/zenodo.4095493 here] ''(Credit: Thomas McKenzie, Aalto)''.
*'''New: [https://sofacoustics.org/data/database/6dof%20dataset/ 6DoF dataset]''': SRIRs measured in a variable acoustics room with two spherical microphone arrays. For description, see [https://doi.org/10.5281/zenodo.5720723 here]. ''(Credit: Thomas McKenzie, Aalto)''.

== Headphone impulse responses (HpIRs) ==

* [http://sofacoustics.org/data/headphones/ari ARI]: HpIRs of human listeners from the ARI database. Single headphone, five measurements (with repositioned headphone in-between) for over 100 listeners.
* [http://sofacoustics.org/data/headphones/btdei BT-DEI]: HpIRs of human listeners from the [http://padva.dei.unipd.it/?page_id=345 BT-DEI] database. 16 listeners, three headphones ''(Credit: Michele Geronazzo, Italy)''.
* [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN]: HpIRs of the FABIAN mannequin. Acoustically measured for 34 headphones. ''(Credit: Fabian Brinkmann, Germany)''.

== Example & Test SOFA Files ==

* [http://sofacoustics.org/data/examples/ Example files]: SOFA example & test files for stable [[SOFA_conventions|conventions]]; these files are a subset of other databases on this page, renamed according their conventions.
* [http://sofacoustics.org/data/sofa_api_mo_test sofa_api_mo_test]: HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA API for Matlab/Octave]

== Other repositories ==

This is a list of other repositories providing HRTFs, BRIRs, and DRIRs available as SOFA files.

* '''ARI free-field HRTF database'''. HRTFs available for in-the-ear (ITE) and behind-the-ear (BTE) HRTFs. Link: https://www.oeaw.ac.at/isf/hrtf
* '''Example files''' created by the Matlab/Octave API. Link: http://tinyurl.com/sofaHRTFs
* [https://www.york.ac.uk/sadie-project/database.html SADIE]: Far-field HRTFs from the [https://www.york.ac.uk/sadie-project/ SADIE] project of over 20 human listeners. ''(Credit: Gavin Kearney, York)''

== Database missing? ==
If you want your/a SOFA database to be added please [https://www.sofaconventions.org/mediawiki/index.php/People_behind_SOFA contact Michael Mihocic or Piotr Majdak] for support.

SOFA (Spatially Oriented Format for Acoustics)

2022-07-18T12:09:26Z

Petibub: SCUT: HRTFs and anthropometric data

SOFA is a file format for storing [http://en.wikipedia.org/wiki/Spatial_sound spatially] oriented acoustic data like [http://en.wikipedia.org/wiki/Head-related_transfer_function head-related transfer functions (HRTFs]) and binaural or spatial room [http://en.wikipedia.org/wiki/Impulse_response impulse responses] (BRIRs, SRIRs). SOFA has been standardized by the [http://aes.org Audio Engineering Society (AES)] as [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015]. This website aims at providing SOFA-relevant information.
* [[General information on SOFA]]
* [[SOFA specifications]]

SOFA conventions are designed for a consistent description of data stored in SOFA. The aim is the exchange of the data between researches and users. For each conventions, data exist from corresponding measurement setups and its description has been accepted by the peer group. Suggestions for new SOFA conventions and additions to existing ones are highly welcome.
* [[SOFA conventions]]

List of repositories with SOFA files containing [http://en.wikipedia.org/wiki/Head-related_transfer_function HRTFs], PRTFs, BRIRs, and DRIRs measured by different researchers.

* [[Files|Files (HRTFs, BRIRs, DRIRs, HpIRs)]]

SOFA files can be read and modified by software and application-programming interfaces (APIs).
* [[Software and APIs]]

SOFA is result of the work of many people from various institutions.
* [[People behind SOFA]]

The SOFA project got awarded with the Reproducibility in Audio and Music Research Prize 2013 [http://soundsoftware.ac.uk/rr-prize-winner-announcement].

== News history ==
* 18.07.2022: SCUT: Near-field HRTFs and anthropometric data of listeners
* 18.07.2022: CIPIC: Local copy of anthropometric data provided because original site down.
* 02.05.2022: CIPIC data fixed
* 28.12.2021: Room Transition dataset added (Credit: Thomas McKenzie, Aalto)
* 28.12.2021: 6DoF dataset added (Credit: Thomas McKenzie, Aalto)
* 28.12.2021: SADIE database added (Credit: Gavin Kearney and Cal Armstrong, York)
* 28.12.2021: Listen database added (Credit: Markus Noisternig, Paris)
* 28.12.2021: Crossmod database added (Credit: Markus Noisternig, Paris)
* 28.12.2021: BiLi database added (Credit: Markus Noisternig, Paris)
* 14.12.2021: Application WaveCloud-M removed (broken link, university cannot provide application)
* 02.11.2021: sofar, a SOFA API for Python added (Credit: Fabian Brinkmann, Berlin)
* 27.10.2021: Application Individualized HRTF Synthesis added to Software and APIs (Credit: Davi Carvalho, Federal University of Santa Maria, Brasil)
* 19.10.2021: 3D3A, HRTFs and 3D scans from the Princeton database added (Credit: Edgar Choueiri, USA)
* 11.10.2021: Application Webcam Headtracker added to Software and APIs
* 02.07.2021: Application Binaural Audio database added to Software and APIs
* 28.06.2021: PKU-IOA, High spatial resolution in-the-ear HRTFs added (Credit: Tianshu Qu, China)
* 25.06.2021: Several external links updated
* 12.02.2021: Test and example files added to files
* 02.02.2021: TU Berlin, Directivity HRTFs (sources) added (Credit: David Ackermann, Germany)
* 15.01.2021: Aachen, High-resolution HRTFs (human, and KEMAR dummy head) added (Credit: Janina Fels, Aachen)
* 27.11.2020: VIKING, Full-sphere HRTFs (.sofa) added (Credit: Simone Spagnol, Denmark)
* 04.06.2020: CHEDAR, numerically calculated HRTFs added (Credit: Slim Ghorbal, France)
* 07.04.2020: Applications 3D Tune-In Toolkit and Anaglyph added
* 31.01.2020: HUTUBS, HRTFs from the HUTUBS database added (Credit: Fabian Brinkmann, Berlin)
* 22.01.2020: Widespread (PRTFs and pinna meshes) of 1005 listeners added (Credits: Corentin Guezonoc, CentraleSupélec, Cesson-Sévigné, France)
* 15.10.2019: Head-gear HRTFs of a mannequin added (Credits: Christoph Pörschmann, Technische Hochschule Köln, Germany)
* 04.07.2019: SOFA for Max: object collection for Max added (Credits: Dale Johnson and Hyunkook Lee, APL, HUD, UK)
* 18.06.2019: SOFASonix: Lightweight SOFA API for Python added (Credits: Ioseb Laghidze, Joey Lag, ISVR, Southhampton, UK)
* 28.05.2019: pysofaconventions, a SOFA API for Python added (Credits: Andrés Pérez-López, UPF/Eurecat, Spain)
* 06.09.2018: pySOFA, a SOFA API for Python added (Credits: Jörg Encke, TUM, Munich)
* 05.09.2018: DRIRs from THK added (Credits: Johannes Arend, Tim Lübeck)
* 11.06.2018: DirPat (Application) added (Credits: Franz Zotter and the [https://opendata.iem.at/projects/dirpat/ DirPat] team)
* 13.11.2017: SBSBRIRs added (Credits: Chris Pike)
* 19.07.2017: Aachen HRTF database added (Credits: Janina Fels)
* 13.07.2017: WebSofa added to the Software section (Credits: Christian-W. Budde)
* 25.05.2017: HRTFs and HpIRs of FABIAN from TU-Berlin added (Credits: Fabian Brinkmann)
* 21.11.2016: Near-field HRTFs from the Fachhochschule Köln with 5 different measurement distances
* 16.08.2016: Large update of the Oldenburg BRIRs.
* 05.03.2015: AES standardization process completed. SOFA 1.0 is now [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015].
* 22.10.2014: Files added: HpIRs from the BT-DEI database provided (Credits: Michele Geronazzo, Italy)
* 15.10.2014: Discussion: New datatype "SOS" proposed
* 03.10.2014: Files added: Headphone IRs (HpIRs) from the ARI database for over 100 human listeners provided
* 11.08.2014: Conventions: SimpleHeadphoneIR 0.1 completed
* 23.05.2014: Files added: ARI (ARTIFICIAL), HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners
* 08.04.2014: Files added: ARI B, files with low-frequency content for Hifi listening experience.
* 25.03.2014: Files updated: Update to SOFA 0.6
* 20.03.2014: SOFA 0.6
* 21.03.2014: Files added: RIEC Far-field HRTFs from the RIEC database (Credits: Kajni Watanabe, Japan)
* 20.03.2014: Conventions: SimpleFreeFieldHRIR 0.4 completed
* 27.11.2013: Files added: Near-field HRTFs from SCUT database of the KEMAR (Credits: Bosun Xie, China)
* 18.11.2013: Files added: HRTFs of the dummy-head Neumann K100, gapless and high spatial resolution (Credits: Benjamin Bernschütz)
* 30.08.2013: SOFA 0.5
* 29.08.2013: Files added: DRIRs from Oldenburg. Recordings in an office under several conditions (Credits: Stephan Ewert)
* 29.06.2013: Conventions: GeneralFIR and GeneralTF completed
* 21.06.2013: Files added: ARI, LISTEN, CIPIC, MIT KEMAR, TU-Berlin
* 20.08.2013: Conventions: SimpleFreeFieldHRIR 0.3 proposed
* 17.05.2013: SOFA 0.3
* 17.05.2013: Website released

Files

2022-07-18T12:08:29Z

Petibub: /* General purpose free-field databases (HRTFs, PRTFs) */

The [http://sofacoustics.org/data main SOFA repository] aims at collect the worldwide available HRTFs, BRIRs, DRIRs, and other SOFA-related data at a single place. It is just in the process of being created: Partial download, metadata access, and database search is not available (yet, we are investigating the possibility of using [http://www.opendap.org/ OPeNDAP] for SOFA repositories). Currently, the data can be accessed and downloaded as they are and the metadata are provided in the particular files.

== General purpose free-field [http://sofacoustics.org/data/database databases] (HRTFs, PRTFs) ==

Standard (in-the-ear canal) HRTFs of humans:
* [http://sofacoustics.org/data/database/ari ARI]: HRTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database]. In-the-ear HRTFs and DTFs for over 220 listeners.
** hrtf, dtf: HRTFs and DTFs, respectively, equalized between 300 Hz and 18 kHz
** hrtf b/c, dtf b/c: HRTFs and DTFs, equalized between 50 Hz and 18 kHz for hi-fi auralizations ("b" and "c" differ each other only in their starting positions and the order of measurement positions: b: 0°→0°, c: 270°→270°; direction always clockwise ↻)
* [http://sofacoustics.org/data/database/ari%20(altb) ARI (ALTB)]: HRTFs from the ARI database. Measurements for some of the listeners from the ARI database, repeated and evaluated a few years later, see [http://www.researchgate.net/publication/236111930_Sound_localization_in_individualized_and_non-individualized_crosstalk_cancellation_systems Majdak et al. (2013)].
* [http://sofacoustics.org/data/database/cipic CIPIC]: HRTFs from the [https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/ CIPIC database]. 45 listeners, partially [https://sofacoustics.org/data/database/cipic/anthropometry.zip anthropometric data] available.
* [http://sofacoustics.org/data/database/riec RIEC]: Far-field HRTFs from the [http://www.riec.tohoku.ac.jp/pub/hrtf/index.html RIEC] database from the Advanced Acoustic Information Systems Laboratory, Research Institute of Electrical Communication, Tohoku University, Japan of over 100 human listeners. ''(Credit: Kajni Watanabe, Japan)''
* [http://sofacoustics.org/data/database/aachen Aachen]: HRTFs from the [http://www.akustik.rwth-aachen.de/go/id/lsly Aachen HRTF database], combined with anthropometric data and 3D ear models of 48 listeners. See the [http://gershwin.akustik.rwth-aachen.de/hrtf/hrtf-lic.php license]. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution)/ Aachen: High-resolution HRTFs] from the [https://publications.rwth-aachen.de/record/793261 Aachen HRTF database], combined with a [https://publications.rwth-aachen.de/record/793260 3D model] of one human listener. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/hutubs/ HUTUBS]: HRTFs from the [https://dx.doi.org/10.14279/depositonce-8487 HUTUBS] database containing anthropometric data, headphone impulse responses, and 3D head models from 96 listeners. The database acquisition is detailed in the accompanying [https://doi.org/10.17743/jaes.2019.0024 paper]. ''(Credit: Fabian Brinkmann, Berlin)''
* [http://sofacoustics.org/data/database/chedar/ CHEDAR]: Numerically calculated HRTFs (.sofa) with 3D meshes of the head and pinnae (.ply) and anthropometric data (.mat) provided. For more details, see the [http://sofacoustics.org/data/database/chedar/documentation.pdf documentation]. ''(Credit: Slim Ghorbal, France)''
* [https://sofacoustics.org/data/database/3d3a/ 3D3A]: Measured in-the-ear HRTFs (.sofa) of 38 subjects, and 3D head and torso scans of 31 subjects from the [http://www.princeton.edu/3D3A/HRTFMeasurements.html Princeton 3D3A Database]. ''(Credit: Edgar Choueiri, USA)''
* [https://sofacoustics.org/data/database/bili%20(dtf)/ BiLi]: Measured in-the-ear HRTF files (.sofa) of 56 subjects. Data are available in [https://sofacoustics.org/data/database/bili%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/bili%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/bili%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/crossmod%20(dtf)/ Crossmod]: Measured in-the-ear HRTF files (.sofa) of 24 subjects. Data are available in [https://sofacoustics.org/data/database/crossmod%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/crossmod%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/crossmod%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ Listen]: Measured in-the-ear HRTF files (.sofa) of 50 subjects. Data are available in [https://sofacoustics.org/data/database/listen%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/listen%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/listen%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/sadie/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 18 human subjects (indices H3 to H20). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* '''New: [http://sofacoustics.org/data/database/scut SCUT]''': Near-field HRTFs with anthropometric data (see CSV and PDF). ''(Credit: Guangzheng Yu & Yu Lan, China)''

HRTFs of artificial heads:
* [http://sofacoustics.org/data/database/mit MIT-KEMAR]: HRTFs from [http://sound.media.mit.edu/resources/KEMAR/ MIT of the KEMAR] dummy head. Reference HRTFs used in many publications.
* [http://sofacoustics.org/data/database/ari%20(artificial) ARI (ARTIFICIAL)]: HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners:
** NH169: HRTFs, DTFs, and raw data of a printed head of the corresponding human listener
** NH172: HRTFs, DTFs, raw and reference data of the dummy head Neumann KU 100. Also part of Club Fritz, see below.
* [http://sofacoustics.org/data/database/thk THK/HRIR_*]: HRTFs of various mannequins provided by the Technische Hochschule Köln (TH Köln, previously Fachhochschule Köln); further details can be found here:
** [https://zenodo.org/record/3928297 Far-field HRTFs]: Gapless data, high spatial resolution HRTFs of Neumann KU100. Files: HRIR_CIRC360, HRIR_CIRC360RM, HRIR_FULL2DEG, HRIR_L2354, HRIR_L2702.sofa ''(Credit: Benjamin Bernschütz, Germany).''
**[https://zenodo.org/record/4297951 Near-field HRTFs] (HRIR_*_NF*.sofa): High spatial resolution HRTFs of Neumann KU100 done for various distances ''(Credit: Johannes Arend, Germany)''.
**[https://zenodo.org/record/3928465 Head-gear HRTFs of Neumann KU100 and HEAD acoustics HMS II] (KU100*.sofa, HMSII*.sofa): High spatial resolution HRTFs while wearing various head gears ''(Credit: Christoph Pörschmann, Germany)''.
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs from SCUT database of the KEMAR (Radius: 0.2 to 1.0 m). ''(Credit: Bosun Xie, China)''
* [http://sofacoustics.org/data/database/tu-berlin TU-Berlin]:
** HRTFs from [http://doi.org/10.5281/zenodo.55418 TU-Berlin of the KEMAR] dummy-head. HRTFs for several distances (>0.5 m). ''(Credit: Hagen Wierstorf, Germany)''
** HRTFs from [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN] dummy-head. Acoustically measured and numerically calculated HRTFs. ''(Credit: Fabian Brinkmann, Germany)''
* [http://sofacoustics.org/data/database/clubfritz Club Fritz]: HRTFs of Neumann KU 100 measured as part of the Club Fritz project where many institutions measured the exact same artificial head, see [http://dx.doi.org/10.1109/JSTSP.2015.2400417 Andreopoulou et al, (2015)]. ''(Credit: Brian Katz, France)''.
* [http://sofacoustics.org/data/database/viking/ VIKING]: Full-sphere HRTFs (.sofa) from the [https://doi.org/10.5281/zenodo.4160401 Viking database]. KEMAR mannequin with 20 different pairs of artificial silicone pinnae attached, plus a "pinna-less" condition, measured for 1513 different directions. 3D scans of left pinnae are also included (.stl). ''(Credit: Simone Spagnol, Denmark)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution%20kemar)/ Aachen: High-resolution HRTFs of the KEMAR] dummy head from the [https://publications.rwth-aachen.de/record/807373 Aachen HRTF database], combined with a 3D model of one subject. ''(Credit: Janina Fels, Aachen)''
* [https://sofacoustics.org/data/database/pku-ioa/ PKU-IOA:] High spatial resolution in-the-ear HRTF database of the KEMAR dummy head with distance from 20 cm to 160 cm, including 20, 30, 40, 50, 75, 100, 130, and 160 cm. ''(Credit: Tianshu Qu, China)''
* '''New: [https://sofacoustics.org/data/database/listen%20(dtf)/ SADIE]''': Measured in-the-ear HRTF files (.sofa) of 2 dummy heads (indices D1, D2). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''

Special HRTFs:
* [http://sofacoustics.org/data/database/ari%20(bte) ARI (BTE)]: Behind-the-ear HRTFs and DTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database].

PRTFs:
* [http://sofacoustics.org/data/database/widespread Widespread] (Wide dataset of ear shapes and pinna-related transfer functions obtained by random ear drawings): 1005 pinna meshes matched with correspondingly calculated PRTFs from the [https://www.ietr.fr/spip.php?article1618&lang=en FAST team, IETR (CNRS UMR 6164), CentraleSupélec]. The meshes were created by varying principle components obtained from an analysis of 119 pinna meshes of actual listeners. The PRTFs were calculated by means of the boundary-element method for two spatial grids and three distances, see the upcoming publication [http://sofacoustics.org/data/database/widespread/Widespread.pdf (documentation)]. ''(Credit: Corentin Guezenoc, France)''.

== Directivities (sources and receivers) ==

'''Sources''':

* [http://sofacoustics.org/data/database/tu-berlin%20(directivity)/ TU-Berlin]: One data set of a 3-way loudspeaker (low- mid- und high-unite) in 10°x10° resolution, and two data sets of a trumpet, recorded with a 32 channel microphone array, from the TU Berlin. ''(Credit: David Ackermann, Germany)''

'''Receivers''':
* TBA

== Room impulse responses [http://sofacoustics.org/data/database databases] (DRIRs, SRIRs, BRIRs) ==

RIRs/BRIRs/DRIRs:
* [http://sofacoustics.org/data/database/oldenburg Oldenburg] DRIRs from [http://medi.uni-oldenburg.de/hrir/html/download.html Oldenburg]. Recordings in an office under several conditions ''(Credit: Stephan Ewert and Daryl Kelvasa, Germany)''.
* [http://sofacoustics.org/data/database/tuburo TuBuRo]: RIRs (from omnidirectional mic) and BRIRs (from KEMAR) recorded with 64-channel loudspeaker array in a room under various absorbing conditions, see [http://dx.doi.org/10.14279/depositonce-87.2 the source], [https://depositonce.tu-berlin.de/bitstream/11303/245.2/11/AdditionalInformation.pdf notes on the file naming] and [https://secure.aes.org/forum/pubs/ebriefs/?elib=17624 Erbes et al. (2015)]. ''(Credit: Vera Erbes, Rostock, Germany)''.
* [http://sofacoustics.org/data/database/sbsbrir SBSBRIR]: BRIRs from the [http://www.bbc.co.uk/rd/publications/sbsbrir Salford-BBC dataset] measured in a recording room for 12 loudspeakers, each for 15 head orientations ([http://usir.salford.ac.uk/30868/ details]). ''(Credit: Chris Pike, Salford)''.
* [http://sofacoustics.org/data/database/thk THK/DRIR_* and THK/BRIR_*]: DRIRs and BRIRs measured at the WDR broadcast studios with various microphone arrays provided by the Technische Hochschule Köln (TH Köln). For description, see [https://zenodo.org/record/3930833 here]. ''(Credit: Johannes Arend)''.
*'''New: [https://sofacoustics.org/data/database/room%20transition%20dataset/ Room Transition dataset]''': SRIRs capturing the transition between coupled rooms with 101 positions and four coupled room pairs. For description, see [https://doi.org/10.5281/zenodo.4095493 here] ''(Credit: Thomas McKenzie, Aalto)''.
*'''New: [https://sofacoustics.org/data/database/6dof%20dataset/ 6DoF dataset]''': SRIRs measured in a variable acoustics room with two spherical microphone arrays. For description, see [https://doi.org/10.5281/zenodo.5720723 here]. ''(Credit: Thomas McKenzie, Aalto)''.

== Headphone impulse responses (HpIRs) ==

* [http://sofacoustics.org/data/headphones/ari ARI]: HpIRs of human listeners from the ARI database. Single headphone, five measurements (with repositioned headphone in-between) for over 100 listeners.
* [http://sofacoustics.org/data/headphones/btdei BT-DEI]: HpIRs of human listeners from the [http://padva.dei.unipd.it/?page_id=345 BT-DEI] database. 16 listeners, three headphones ''(Credit: Michele Geronazzo, Italy)''.
* [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN]: HpIRs of the FABIAN mannequin. Acoustically measured for 34 headphones. ''(Credit: Fabian Brinkmann, Germany)''.

== Example & Test SOFA Files ==

* [http://sofacoustics.org/data/examples/ Example files]: SOFA example & test files for stable [[SOFA_conventions|conventions]]; these files are a subset of other databases on this page, renamed according their conventions.
* [http://sofacoustics.org/data/sofa_api_mo_test sofa_api_mo_test]: HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA API for Matlab/Octave]

== Other repositories ==

This is a list of other repositories providing HRTFs, BRIRs, and DRIRs available as SOFA files.

* '''ARI free-field HRTF database'''. HRTFs available for in-the-ear (ITE) and behind-the-ear (BTE) HRTFs. Link: https://www.oeaw.ac.at/isf/hrtf
* '''Example files''' created by the Matlab/Octave API. Link: http://tinyurl.com/sofaHRTFs
* [https://www.york.ac.uk/sadie-project/database.html SADIE]: Far-field HRTFs from the [https://www.york.ac.uk/sadie-project/ SADIE] project of over 20 human listeners. ''(Credit: Gavin Kearney, York)''

== Database missing? ==
If you want your/a SOFA database to be added please [https://www.sofaconventions.org/mediawiki/index.php/People_behind_SOFA contact Michael Mihocic or Piotr Majdak] for support.

Files

2022-07-18T12:08:01Z

Petibub: SCUT: Near-field HRTFs with anthropometric data

The [http://sofacoustics.org/data main SOFA repository] aims at collect the worldwide available HRTFs, BRIRs, DRIRs, and other SOFA-related data at a single place. It is just in the process of being created: Partial download, metadata access, and database search is not available (yet, we are investigating the possibility of using [http://www.opendap.org/ OPeNDAP] for SOFA repositories). Currently, the data can be accessed and downloaded as they are and the metadata are provided in the particular files.

== General purpose free-field [http://sofacoustics.org/data/database databases] (HRTFs, PRTFs) ==

Standard (in-the-ear canal) HRTFs of humans:
* [http://sofacoustics.org/data/database/ari ARI]: HRTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database]. In-the-ear HRTFs and DTFs for over 220 listeners.
** hrtf, dtf: HRTFs and DTFs, respectively, equalized between 300 Hz and 18 kHz
** hrtf b/c, dtf b/c: HRTFs and DTFs, equalized between 50 Hz and 18 kHz for hi-fi auralizations ("b" and "c" differ each other only in their starting positions and the order of measurement positions: b: 0°→0°, c: 270°→270°; direction always clockwise ↻)
* [http://sofacoustics.org/data/database/ari%20(altb) ARI (ALTB)]: HRTFs from the ARI database. Measurements for some of the listeners from the ARI database, repeated and evaluated a few years later, see [http://www.researchgate.net/publication/236111930_Sound_localization_in_individualized_and_non-individualized_crosstalk_cancellation_systems Majdak et al. (2013)].
* [http://sofacoustics.org/data/database/cipic CIPIC]: HRTFs from the [https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/ CIPIC database]. 45 listeners, partially [https://sofacoustics.org/data/database/cipic/anthropometry.zip anthropometric data] available.
* [http://sofacoustics.org/data/database/riec RIEC]: Far-field HRTFs from the [http://www.riec.tohoku.ac.jp/pub/hrtf/index.html RIEC] database from the Advanced Acoustic Information Systems Laboratory, Research Institute of Electrical Communication, Tohoku University, Japan of over 100 human listeners. ''(Credit: Kajni Watanabe, Japan)''
* [http://sofacoustics.org/data/database/aachen Aachen]: HRTFs from the [http://www.akustik.rwth-aachen.de/go/id/lsly Aachen HRTF database], combined with anthropometric data and 3D ear models of 48 listeners. See the [http://gershwin.akustik.rwth-aachen.de/hrtf/hrtf-lic.php license]. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution)/ Aachen: High-resolution HRTFs] from the [https://publications.rwth-aachen.de/record/793261 Aachen HRTF database], combined with a [https://publications.rwth-aachen.de/record/793260 3D model] of one human listener. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/hutubs/ HUTUBS]: HRTFs from the [https://dx.doi.org/10.14279/depositonce-8487 HUTUBS] database containing anthropometric data, headphone impulse responses, and 3D head models from 96 listeners. The database acquisition is detailed in the accompanying [https://doi.org/10.17743/jaes.2019.0024 paper]. ''(Credit: Fabian Brinkmann, Berlin)''
* [http://sofacoustics.org/data/database/chedar/ CHEDAR]: Numerically calculated HRTFs (.sofa) with 3D meshes of the head and pinnae (.ply) and anthropometric data (.mat) provided. For more details, see the [http://sofacoustics.org/data/database/chedar/documentation.pdf documentation]. ''(Credit: Slim Ghorbal, France)''
* [https://sofacoustics.org/data/database/3d3a/ 3D3A]: Measured in-the-ear HRTFs (.sofa) of 38 subjects, and 3D head and torso scans of 31 subjects from the [http://www.princeton.edu/3D3A/HRTFMeasurements.html Princeton 3D3A Database]. ''(Credit: Edgar Choueiri, USA)''
* [https://sofacoustics.org/data/database/bili%20(dtf)/ BiLi]: Measured in-the-ear HRTF files (.sofa) of 56 subjects. Data are available in [https://sofacoustics.org/data/database/bili%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/bili%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/bili%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/crossmod%20(dtf)/ Crossmod]: Measured in-the-ear HRTF files (.sofa) of 24 subjects. Data are available in [https://sofacoustics.org/data/database/crossmod%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/crossmod%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/crossmod%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/listen%20(dtf)/ Listen]: Measured in-the-ear HRTF files (.sofa) of 50 subjects. Data are available in [https://sofacoustics.org/data/database/listen%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/listen%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/listen%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* [https://sofacoustics.org/data/database/sadie/ SADIE]: Measured in-the-ear HRTF files (.sofa) of 18 human subjects (indices H3 to H20). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs with anthropometric data (see CSV and PDF). ''(Credit: Guangzheng Yu & Yu Lan, China)''

HRTFs of artificial heads:
* [http://sofacoustics.org/data/database/mit MIT-KEMAR]: HRTFs from [http://sound.media.mit.edu/resources/KEMAR/ MIT of the KEMAR] dummy head. Reference HRTFs used in many publications.
* [http://sofacoustics.org/data/database/ari%20(artificial) ARI (ARTIFICIAL)]: HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners:
** NH169: HRTFs, DTFs, and raw data of a printed head of the corresponding human listener
** NH172: HRTFs, DTFs, raw and reference data of the dummy head Neumann KU 100. Also part of Club Fritz, see below.
* [http://sofacoustics.org/data/database/thk THK/HRIR_*]: HRTFs of various mannequins provided by the Technische Hochschule Köln (TH Köln, previously Fachhochschule Köln); further details can be found here:
** [https://zenodo.org/record/3928297 Far-field HRTFs]: Gapless data, high spatial resolution HRTFs of Neumann KU100. Files: HRIR_CIRC360, HRIR_CIRC360RM, HRIR_FULL2DEG, HRIR_L2354, HRIR_L2702.sofa ''(Credit: Benjamin Bernschütz, Germany).''
**[https://zenodo.org/record/4297951 Near-field HRTFs] (HRIR_*_NF*.sofa): High spatial resolution HRTFs of Neumann KU100 done for various distances ''(Credit: Johannes Arend, Germany)''.
**[https://zenodo.org/record/3928465 Head-gear HRTFs of Neumann KU100 and HEAD acoustics HMS II] (KU100*.sofa, HMSII*.sofa): High spatial resolution HRTFs while wearing various head gears ''(Credit: Christoph Pörschmann, Germany)''.
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs from SCUT database of the KEMAR (Radius: 0.2 to 1.0 m). ''(Credit: Bosun Xie, China)''
* [http://sofacoustics.org/data/database/tu-berlin TU-Berlin]:
** HRTFs from [http://doi.org/10.5281/zenodo.55418 TU-Berlin of the KEMAR] dummy-head. HRTFs for several distances (>0.5 m). ''(Credit: Hagen Wierstorf, Germany)''
** HRTFs from [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN] dummy-head. Acoustically measured and numerically calculated HRTFs. ''(Credit: Fabian Brinkmann, Germany)''
* [http://sofacoustics.org/data/database/clubfritz Club Fritz]: HRTFs of Neumann KU 100 measured as part of the Club Fritz project where many institutions measured the exact same artificial head, see [http://dx.doi.org/10.1109/JSTSP.2015.2400417 Andreopoulou et al, (2015)]. ''(Credit: Brian Katz, France)''.
* [http://sofacoustics.org/data/database/viking/ VIKING]: Full-sphere HRTFs (.sofa) from the [https://doi.org/10.5281/zenodo.4160401 Viking database]. KEMAR mannequin with 20 different pairs of artificial silicone pinnae attached, plus a "pinna-less" condition, measured for 1513 different directions. 3D scans of left pinnae are also included (.stl). ''(Credit: Simone Spagnol, Denmark)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution%20kemar)/ Aachen: High-resolution HRTFs of the KEMAR] dummy head from the [https://publications.rwth-aachen.de/record/807373 Aachen HRTF database], combined with a 3D model of one subject. ''(Credit: Janina Fels, Aachen)''
* [https://sofacoustics.org/data/database/pku-ioa/ PKU-IOA:] High spatial resolution in-the-ear HRTF database of the KEMAR dummy head with distance from 20 cm to 160 cm, including 20, 30, 40, 50, 75, 100, 130, and 160 cm. ''(Credit: Tianshu Qu, China)''
* '''New: [https://sofacoustics.org/data/database/listen%20(dtf)/ SADIE]''': Measured in-the-ear HRTF files (.sofa) of 2 dummy heads (indices D1, D2). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''

Special HRTFs:
* [http://sofacoustics.org/data/database/ari%20(bte) ARI (BTE)]: Behind-the-ear HRTFs and DTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database].

PRTFs:
* [http://sofacoustics.org/data/database/widespread Widespread] (Wide dataset of ear shapes and pinna-related transfer functions obtained by random ear drawings): 1005 pinna meshes matched with correspondingly calculated PRTFs from the [https://www.ietr.fr/spip.php?article1618&lang=en FAST team, IETR (CNRS UMR 6164), CentraleSupélec]. The meshes were created by varying principle components obtained from an analysis of 119 pinna meshes of actual listeners. The PRTFs were calculated by means of the boundary-element method for two spatial grids and three distances, see the upcoming publication [http://sofacoustics.org/data/database/widespread/Widespread.pdf (documentation)]. ''(Credit: Corentin Guezenoc, France)''.

== Directivities (sources and receivers) ==

'''Sources''':

* [http://sofacoustics.org/data/database/tu-berlin%20(directivity)/ TU-Berlin]: One data set of a 3-way loudspeaker (low- mid- und high-unite) in 10°x10° resolution, and two data sets of a trumpet, recorded with a 32 channel microphone array, from the TU Berlin. ''(Credit: David Ackermann, Germany)''

'''Receivers''':
* TBA

== Room impulse responses [http://sofacoustics.org/data/database databases] (DRIRs, SRIRs, BRIRs) ==

RIRs/BRIRs/DRIRs:
* [http://sofacoustics.org/data/database/oldenburg Oldenburg] DRIRs from [http://medi.uni-oldenburg.de/hrir/html/download.html Oldenburg]. Recordings in an office under several conditions ''(Credit: Stephan Ewert and Daryl Kelvasa, Germany)''.
* [http://sofacoustics.org/data/database/tuburo TuBuRo]: RIRs (from omnidirectional mic) and BRIRs (from KEMAR) recorded with 64-channel loudspeaker array in a room under various absorbing conditions, see [http://dx.doi.org/10.14279/depositonce-87.2 the source], [https://depositonce.tu-berlin.de/bitstream/11303/245.2/11/AdditionalInformation.pdf notes on the file naming] and [https://secure.aes.org/forum/pubs/ebriefs/?elib=17624 Erbes et al. (2015)]. ''(Credit: Vera Erbes, Rostock, Germany)''.
* [http://sofacoustics.org/data/database/sbsbrir SBSBRIR]: BRIRs from the [http://www.bbc.co.uk/rd/publications/sbsbrir Salford-BBC dataset] measured in a recording room for 12 loudspeakers, each for 15 head orientations ([http://usir.salford.ac.uk/30868/ details]). ''(Credit: Chris Pike, Salford)''.
* [http://sofacoustics.org/data/database/thk THK/DRIR_* and THK/BRIR_*]: DRIRs and BRIRs measured at the WDR broadcast studios with various microphone arrays provided by the Technische Hochschule Köln (TH Köln). For description, see [https://zenodo.org/record/3930833 here]. ''(Credit: Johannes Arend)''.
*'''New: [https://sofacoustics.org/data/database/room%20transition%20dataset/ Room Transition dataset]''': SRIRs capturing the transition between coupled rooms with 101 positions and four coupled room pairs. For description, see [https://doi.org/10.5281/zenodo.4095493 here] ''(Credit: Thomas McKenzie, Aalto)''.
*'''New: [https://sofacoustics.org/data/database/6dof%20dataset/ 6DoF dataset]''': SRIRs measured in a variable acoustics room with two spherical microphone arrays. For description, see [https://doi.org/10.5281/zenodo.5720723 here]. ''(Credit: Thomas McKenzie, Aalto)''.

== Headphone impulse responses (HpIRs) ==

* [http://sofacoustics.org/data/headphones/ari ARI]: HpIRs of human listeners from the ARI database. Single headphone, five measurements (with repositioned headphone in-between) for over 100 listeners.
* [http://sofacoustics.org/data/headphones/btdei BT-DEI]: HpIRs of human listeners from the [http://padva.dei.unipd.it/?page_id=345 BT-DEI] database. 16 listeners, three headphones ''(Credit: Michele Geronazzo, Italy)''.
* [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN]: HpIRs of the FABIAN mannequin. Acoustically measured for 34 headphones. ''(Credit: Fabian Brinkmann, Germany)''.

== Example & Test SOFA Files ==

* [http://sofacoustics.org/data/examples/ Example files]: SOFA example & test files for stable [[SOFA_conventions|conventions]]; these files are a subset of other databases on this page, renamed according their conventions.
* [http://sofacoustics.org/data/sofa_api_mo_test sofa_api_mo_test]: HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA API for Matlab/Octave]

== Other repositories ==

This is a list of other repositories providing HRTFs, BRIRs, and DRIRs available as SOFA files.

* '''ARI free-field HRTF database'''. HRTFs available for in-the-ear (ITE) and behind-the-ear (BTE) HRTFs. Link: https://www.oeaw.ac.at/isf/hrtf
* '''Example files''' created by the Matlab/Octave API. Link: http://tinyurl.com/sofaHRTFs
* [https://www.york.ac.uk/sadie-project/database.html SADIE]: Far-field HRTFs from the [https://www.york.ac.uk/sadie-project/ SADIE] project of over 20 human listeners. ''(Credit: Gavin Kearney, York)''

== Database missing? ==
If you want your/a SOFA database to be added please [https://www.sofaconventions.org/mediawiki/index.php/People_behind_SOFA contact Michael Mihocic or Piotr Majdak] for support.

SOFA (Spatially Oriented Format for Acoustics)

2022-07-18T08:29:00Z

Petibub: /* News history */

SOFA is a file format for storing [http://en.wikipedia.org/wiki/Spatial_sound spatially] oriented acoustic data like [http://en.wikipedia.org/wiki/Head-related_transfer_function head-related transfer functions (HRTFs]) and binaural or spatial room [http://en.wikipedia.org/wiki/Impulse_response impulse responses] (BRIRs, SRIRs). SOFA has been standardized by the [http://aes.org Audio Engineering Society (AES)] as [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015]. This website aims at providing SOFA-relevant information.
* [[General information on SOFA]]
* [[SOFA specifications]]

SOFA conventions are designed for a consistent description of data stored in SOFA. The aim is the exchange of the data between researches and users. For each conventions, data exist from corresponding measurement setups and its description has been accepted by the peer group. Suggestions for new SOFA conventions and additions to existing ones are highly welcome.
* [[SOFA conventions]]

List of repositories with SOFA files containing [http://en.wikipedia.org/wiki/Head-related_transfer_function HRTFs], PRTFs, BRIRs, and DRIRs measured by different researchers.

* [[Files|Files (HRTFs, BRIRs, DRIRs, HpIRs)]]

SOFA files can be read and modified by software and application-programming interfaces (APIs).
* [[Software and APIs]]

SOFA is result of the work of many people from various institutions.
* [[People behind SOFA]]

The SOFA project got awarded with the Reproducibility in Audio and Music Research Prize 2013 [http://soundsoftware.ac.uk/rr-prize-winner-announcement].

== News history ==
* 18.07.2022: CIPIC: Local copy of anthropometric data provided because original site down.
* 02.05.2022: CIPIC data fixed
* 28.12.2021: Room Transition dataset added (Credit: Thomas McKenzie, Aalto)
* 28.12.2021: 6DoF dataset added (Credit: Thomas McKenzie, Aalto)
* 28.12.2021: SADIE database added (Credit: Gavin Kearney and Cal Armstrong, York)
* 28.12.2021: Listen database added (Credit: Markus Noisternig, Paris)
* 28.12.2021: Crossmod database added (Credit: Markus Noisternig, Paris)
* 28.12.2021: BiLi database added (Credit: Markus Noisternig, Paris)
* 14.12.2021: Application WaveCloud-M removed (broken link, university cannot provide application)
* 02.11.2021: sofar, a SOFA API for Python added (Credit: Fabian Brinkmann, Berlin)
* 27.10.2021: Application Individualized HRTF Synthesis added to Software and APIs (Credit: Davi Carvalho, Federal University of Santa Maria, Brasil)
* 19.10.2021: 3D3A, HRTFs and 3D scans from the Princeton database added (Credit: Edgar Choueiri, USA)
* 11.10.2021: Application Webcam Headtracker added to Software and APIs
* 02.07.2021: Application Binaural Audio database added to Software and APIs
* 28.06.2021: PKU-IOA, High spatial resolution in-the-ear HRTFs added (Credit: Tianshu Qu, China)
* 25.06.2021: Several external links updated
* 12.02.2021: Test and example files added to files
* 02.02.2021: TU Berlin, Directivity HRTFs (sources) added (Credit: David Ackermann, Germany)
* 15.01.2021: Aachen, High-resolution HRTFs (human, and KEMAR dummy head) added (Credit: Janina Fels, Aachen)
* 27.11.2020: VIKING, Full-sphere HRTFs (.sofa) added (Credit: Simone Spagnol, Denmark)
* 04.06.2020: CHEDAR, numerically calculated HRTFs added (Credit: Slim Ghorbal, France)
* 07.04.2020: Applications 3D Tune-In Toolkit and Anaglyph added
* 31.01.2020: HUTUBS, HRTFs from the HUTUBS database added (Credit: Fabian Brinkmann, Berlin)
* 22.01.2020: Widespread (PRTFs and pinna meshes) of 1005 listeners added (Credits: Corentin Guezonoc, CentraleSupélec, Cesson-Sévigné, France)
* 15.10.2019: Head-gear HRTFs of a mannequin added (Credits: Christoph Pörschmann, Technische Hochschule Köln, Germany)
* 04.07.2019: SOFA for Max: object collection for Max added (Credits: Dale Johnson and Hyunkook Lee, APL, HUD, UK)
* 18.06.2019: SOFASonix: Lightweight SOFA API for Python added (Credits: Ioseb Laghidze, Joey Lag, ISVR, Southhampton, UK)
* 28.05.2019: pysofaconventions, a SOFA API for Python added (Credits: Andrés Pérez-López, UPF/Eurecat, Spain)
* 06.09.2018: pySOFA, a SOFA API for Python added (Credits: Jörg Encke, TUM, Munich)
* 05.09.2018: DRIRs from THK added (Credits: Johannes Arend, Tim Lübeck)
* 11.06.2018: DirPat (Application) added (Credits: Franz Zotter and the [https://opendata.iem.at/projects/dirpat/ DirPat] team)
* 13.11.2017: SBSBRIRs added (Credits: Chris Pike)
* 19.07.2017: Aachen HRTF database added (Credits: Janina Fels)
* 13.07.2017: WebSofa added to the Software section (Credits: Christian-W. Budde)
* 25.05.2017: HRTFs and HpIRs of FABIAN from TU-Berlin added (Credits: Fabian Brinkmann)
* 21.11.2016: Near-field HRTFs from the Fachhochschule Köln with 5 different measurement distances
* 16.08.2016: Large update of the Oldenburg BRIRs.
* 05.03.2015: AES standardization process completed. SOFA 1.0 is now [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015].
* 22.10.2014: Files added: HpIRs from the BT-DEI database provided (Credits: Michele Geronazzo, Italy)
* 15.10.2014: Discussion: New datatype "SOS" proposed
* 03.10.2014: Files added: Headphone IRs (HpIRs) from the ARI database for over 100 human listeners provided
* 11.08.2014: Conventions: SimpleHeadphoneIR 0.1 completed
* 23.05.2014: Files added: ARI (ARTIFICIAL), HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners
* 08.04.2014: Files added: ARI B, files with low-frequency content for Hifi listening experience.
* 25.03.2014: Files updated: Update to SOFA 0.6
* 20.03.2014: SOFA 0.6
* 21.03.2014: Files added: RIEC Far-field HRTFs from the RIEC database (Credits: Kajni Watanabe, Japan)
* 20.03.2014: Conventions: SimpleFreeFieldHRIR 0.4 completed
* 27.11.2013: Files added: Near-field HRTFs from SCUT database of the KEMAR (Credits: Bosun Xie, China)
* 18.11.2013: Files added: HRTFs of the dummy-head Neumann K100, gapless and high spatial resolution (Credits: Benjamin Bernschütz)
* 30.08.2013: SOFA 0.5
* 29.08.2013: Files added: DRIRs from Oldenburg. Recordings in an office under several conditions (Credits: Stephan Ewert)
* 29.06.2013: Conventions: GeneralFIR and GeneralTF completed
* 21.06.2013: Files added: ARI, LISTEN, CIPIC, MIT KEMAR, TU-Berlin
* 20.08.2013: Conventions: SimpleFreeFieldHRIR 0.3 proposed
* 17.05.2013: SOFA 0.3
* 17.05.2013: Website released

Files

2022-07-18T08:25:14Z

Petibub: CIPIC: Link to a local copy of anthropometric data added

The [http://sofacoustics.org/data main SOFA repository] aims at collect the worldwide available HRTFs, BRIRs, DRIRs, and other SOFA-related data at a single place. It is just in the process of being created: Partial download, metadata access, and database search is not available (yet, we are investigating the possibility of using [http://www.opendap.org/ OPeNDAP] for SOFA repositories). Currently, the data can be accessed and downloaded as they are and the metadata are provided in the particular files.

== General purpose free-field [http://sofacoustics.org/data/database databases] (HRTFs, PRTFs) ==

Standard (in-the-ear canal) HRTFs of humans:
* [http://sofacoustics.org/data/database/ari ARI]: HRTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database]. In-the-ear HRTFs and DTFs for over 220 listeners.
** hrtf, dtf: HRTFs and DTFs, respectively, equalized between 300 Hz and 18 kHz
** hrtf b/c, dtf b/c: HRTFs and DTFs, equalized between 50 Hz and 18 kHz for hi-fi auralizations ("b" and "c" differ each other only in their starting positions and the order of measurement positions: b: 0°→0°, c: 270°→270°; direction always clockwise ↻)
* [http://sofacoustics.org/data/database/ari%20(altb) ARI (ALTB)]: HRTFs from the ARI database. Measurements for some of the listeners from the ARI database, repeated and evaluated a few years later, see [http://www.researchgate.net/publication/236111930_Sound_localization_in_individualized_and_non-individualized_crosstalk_cancellation_systems Majdak et al. (2013)].
* [http://sofacoustics.org/data/database/cipic CIPIC]: HRTFs from the [https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/ CIPIC database]. 45 listeners, partially [https://sofacoustics.org/data/database/cipic/anthropometry.zip anthropometric data] available.
* [http://sofacoustics.org/data/database/riec RIEC]: Far-field HRTFs from the [http://www.riec.tohoku.ac.jp/pub/hrtf/index.html RIEC] database from the Advanced Acoustic Information Systems Laboratory, Research Institute of Electrical Communication, Tohoku University, Japan of over 100 human listeners. ''(Credit: Kajni Watanabe, Japan)''
* [http://sofacoustics.org/data/database/aachen Aachen]: HRTFs from the [http://www.akustik.rwth-aachen.de/go/id/lsly Aachen HRTF database], combined with anthropometric data and 3D ear models of 48 listeners. See the [http://gershwin.akustik.rwth-aachen.de/hrtf/hrtf-lic.php license]. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution)/ Aachen: High-resolution HRTFs] from the [https://publications.rwth-aachen.de/record/793261 Aachen HRTF database], combined with a [https://publications.rwth-aachen.de/record/793260 3D model] of one human listener. ''(Credit: Janina Fels, Aachen)''
* [http://sofacoustics.org/data/database/hutubs/ HUTUBS]: HRTFs from the [https://dx.doi.org/10.14279/depositonce-8487 HUTUBS] database containing anthropometric data, headphone impulse responses, and 3D head models from 96 listeners. The database acquisition is detailed in the accompanying [https://doi.org/10.17743/jaes.2019.0024 paper]. ''(Credit: Fabian Brinkmann, Berlin)''
* [http://sofacoustics.org/data/database/chedar/ CHEDAR]: Numerically calculated HRTFs (.sofa) with 3D meshes of the head and pinnae (.ply) and anthropometric data (.mat) provided. For more details, see the [http://sofacoustics.org/data/database/chedar/documentation.pdf documentation]. ''(Credit: Slim Ghorbal, France)''
* [https://sofacoustics.org/data/database/3d3a/ 3D3A]: Measured in-the-ear HRTFs (.sofa) of 38 subjects, and 3D head and torso scans of 31 subjects from the [http://www.princeton.edu/3D3A/HRTFMeasurements.html Princeton 3D3A Database]. ''(Credit: Edgar Choueiri, USA)''
* '''New: [https://sofacoustics.org/data/database/bili%20(dtf)/ BiLi]''': Measured in-the-ear HRTF files (.sofa) of 56 subjects. Data are available in [https://sofacoustics.org/data/database/bili%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/bili%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/bili%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* '''New: [https://sofacoustics.org/data/database/crossmod%20(dtf)/ Crossmod]''': Measured in-the-ear HRTF files (.sofa) of 24 subjects. Data are available in [https://sofacoustics.org/data/database/crossmod%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/crossmod%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/crossmod%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* '''New: [https://sofacoustics.org/data/database/listen%20(dtf)/ Listen]''': Measured in-the-ear HRTF files (.sofa) of 50 subjects. Data are available in [https://sofacoustics.org/data/database/listen%20(dtf)/ DTF format], raw [https://sofacoustics.org/data/database/listen%20(hrtf)/ HRTF format], and as DTF format in [https://sofacoustics.org/data/database/listen%20(dtf,%20sos)/ SOS data type]. Multiple sampling rates of these data are available on the [http://opendap.ircam.fr/download/ download page] of the [http://bili2.ircam.fr/ IRCAM database]. ''(Credit: Markus Noisternig, Paris)''
* '''New: [https://sofacoustics.org/data/database/sadie/ SADIE]''': Measured in-the-ear HRTF files (.sofa) of 18 human subjects (indices H3 to H20). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''

HRTFs of artificial heads:
* [http://sofacoustics.org/data/database/mit MIT-KEMAR]: HRTFs from [http://sound.media.mit.edu/resources/KEMAR/ MIT of the KEMAR] dummy head. Reference HRTFs used in many publications.
* [http://sofacoustics.org/data/database/ari%20(artificial) ARI (ARTIFICIAL)]: HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners:
** NH169: HRTFs, DTFs, and raw data of a printed head of the corresponding human listener
** NH172: HRTFs, DTFs, raw and reference data of the dummy head Neumann KU 100. Also part of Club Fritz, see below.
* [http://sofacoustics.org/data/database/thk THK/HRIR_*]: HRTFs of various mannequins provided by the Technische Hochschule Köln (TH Köln, previously Fachhochschule Köln); further details can be found here:
** [https://zenodo.org/record/3928297 Far-field HRTFs]: Gapless data, high spatial resolution HRTFs of Neumann KU100. Files: HRIR_CIRC360, HRIR_CIRC360RM, HRIR_FULL2DEG, HRIR_L2354, HRIR_L2702.sofa ''(Credit: Benjamin Bernschütz, Germany).''
**[https://zenodo.org/record/4297951 Near-field HRTFs] (HRIR_*_NF*.sofa): High spatial resolution HRTFs of Neumann KU100 done for various distances ''(Credit: Johannes Arend, Germany)''.
**[https://zenodo.org/record/3928465 Head-gear HRTFs of Neumann KU100 and HEAD acoustics HMS II] (KU100*.sofa, HMSII*.sofa): High spatial resolution HRTFs while wearing various head gears ''(Credit: Christoph Pörschmann, Germany)''.
* [http://sofacoustics.org/data/database/scut SCUT]: Near-field HRTFs from SCUT database of the KEMAR (Radius: 0.2 to 1.0 m). ''(Credit: Bosun Xie, China)''
* [http://sofacoustics.org/data/database/tu-berlin TU-Berlin]:
** HRTFs from [http://doi.org/10.5281/zenodo.55418 TU-Berlin of the KEMAR] dummy-head. HRTFs for several distances (>0.5 m). ''(Credit: Hagen Wierstorf, Germany)''
** HRTFs from [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN] dummy-head. Acoustically measured and numerically calculated HRTFs. ''(Credit: Fabian Brinkmann, Germany)''
* [http://sofacoustics.org/data/database/clubfritz Club Fritz]: HRTFs of Neumann KU 100 measured as part of the Club Fritz project where many institutions measured the exact same artificial head, see [http://dx.doi.org/10.1109/JSTSP.2015.2400417 Andreopoulou et al, (2015)]. ''(Credit: Brian Katz, France)''.
* [http://sofacoustics.org/data/database/viking/ VIKING]: Full-sphere HRTFs (.sofa) from the [https://doi.org/10.5281/zenodo.4160401 Viking database]. KEMAR mannequin with 20 different pairs of artificial silicone pinnae attached, plus a "pinna-less" condition, measured for 1513 different directions. 3D scans of left pinnae are also included (.stl). ''(Credit: Simone Spagnol, Denmark)''
* [http://sofacoustics.org/data/database/aachen%20(high-resolution%20kemar)/ Aachen: High-resolution HRTFs of the KEMAR] dummy head from the [https://publications.rwth-aachen.de/record/807373 Aachen HRTF database], combined with a 3D model of one subject. ''(Credit: Janina Fels, Aachen)''
* [https://sofacoustics.org/data/database/pku-ioa/ PKU-IOA:] High spatial resolution in-the-ear HRTF database of the KEMAR dummy head with distance from 20 cm to 160 cm, including 20, 30, 40, 50, 75, 100, 130, and 160 cm. ''(Credit: Tianshu Qu, China)''
* '''New: [https://sofacoustics.org/data/database/listen%20(dtf)/ SADIE]''': Measured in-the-ear HRTF files (.sofa) of 2 dummy heads (indices D1, D2). 3D scans area available on the website of the [https://www.york.ac.uk/sadie-project/database.html SADIE II datebase]. ''(Credit: Gavin Kearney and Cal Armstrong, York)''

Special HRTFs:
* [http://sofacoustics.org/data/database/ari%20(bte) ARI (BTE)]: Behind-the-ear HRTFs and DTFs from the [https://www.oeaw.ac.at/isf/hrtf ARI database].

PRTFs:
* [http://sofacoustics.org/data/database/widespread Widespread] (Wide dataset of ear shapes and pinna-related transfer functions obtained by random ear drawings): 1005 pinna meshes matched with correspondingly calculated PRTFs from the [https://www.ietr.fr/spip.php?article1618&lang=en FAST team, IETR (CNRS UMR 6164), CentraleSupélec]. The meshes were created by varying principle components obtained from an analysis of 119 pinna meshes of actual listeners. The PRTFs were calculated by means of the boundary-element method for two spatial grids and three distances, see the upcoming publication [http://sofacoustics.org/data/database/widespread/Widespread.pdf (documentation)]. ''(Credit: Corentin Guezenoc, France)''.

== Directivities (sources and receivers) ==

'''Sources''':

* [http://sofacoustics.org/data/database/tu-berlin%20(directivity)/ TU-Berlin]: One data set of a 3-way loudspeaker (low- mid- und high-unite) in 10°x10° resolution, and two data sets of a trumpet, recorded with a 32 channel microphone array, from the TU Berlin. ''(Credit: David Ackermann, Germany)''

'''Receivers''':
* TBA

== Room impulse responses [http://sofacoustics.org/data/database databases] (DRIRs, SRIRs, BRIRs) ==

RIRs/BRIRs/DRIRs:
* [http://sofacoustics.org/data/database/oldenburg Oldenburg] DRIRs from [http://medi.uni-oldenburg.de/hrir/html/download.html Oldenburg]. Recordings in an office under several conditions ''(Credit: Stephan Ewert and Daryl Kelvasa, Germany)''.
* [http://sofacoustics.org/data/database/tuburo TuBuRo]: RIRs (from omnidirectional mic) and BRIRs (from KEMAR) recorded with 64-channel loudspeaker array in a room under various absorbing conditions, see [http://dx.doi.org/10.14279/depositonce-87.2 the source], [https://depositonce.tu-berlin.de/bitstream/11303/245.2/11/AdditionalInformation.pdf notes on the file naming] and [https://secure.aes.org/forum/pubs/ebriefs/?elib=17624 Erbes et al. (2015)]. ''(Credit: Vera Erbes, Rostock, Germany)''.
* [http://sofacoustics.org/data/database/sbsbrir SBSBRIR]: BRIRs from the [http://www.bbc.co.uk/rd/publications/sbsbrir Salford-BBC dataset] measured in a recording room for 12 loudspeakers, each for 15 head orientations ([http://usir.salford.ac.uk/30868/ details]). ''(Credit: Chris Pike, Salford)''.
* [http://sofacoustics.org/data/database/thk THK/DRIR_* and THK/BRIR_*]: DRIRs and BRIRs measured at the WDR broadcast studios with various microphone arrays provided by the Technische Hochschule Köln (TH Köln). For description, see [https://zenodo.org/record/3930833 here]. ''(Credit: Johannes Arend)''.
*'''New: [https://sofacoustics.org/data/database/room%20transition%20dataset/ Room Transition dataset]''': SRIRs capturing the transition between coupled rooms with 101 positions and four coupled room pairs. For description, see [https://doi.org/10.5281/zenodo.4095493 here] ''(Credit: Thomas McKenzie, Aalto)''.
*'''New: [https://sofacoustics.org/data/database/6dof%20dataset/ 6DoF dataset]''': SRIRs measured in a variable acoustics room with two spherical microphone arrays. For description, see [https://doi.org/10.5281/zenodo.5720723 here]. ''(Credit: Thomas McKenzie, Aalto)''.

== Headphone impulse responses (HpIRs) ==

* [http://sofacoustics.org/data/headphones/ari ARI]: HpIRs of human listeners from the ARI database. Single headphone, five measurements (with repositioned headphone in-between) for over 100 listeners.
* [http://sofacoustics.org/data/headphones/btdei BT-DEI]: HpIRs of human listeners from the [http://padva.dei.unipd.it/?page_id=345 BT-DEI] database. 16 listeners, three headphones ''(Credit: Michele Geronazzo, Italy)''.
* [https://depositonce.tu-berlin.de/handle/11303/6153 TU-Berlin of the FABIAN]: HpIRs of the FABIAN mannequin. Acoustically measured for 34 headphones. ''(Credit: Fabian Brinkmann, Germany)''.

== Example & Test SOFA Files ==

* [http://sofacoustics.org/data/examples/ Example files]: SOFA example & test files for stable [[SOFA_conventions|conventions]]; these files are a subset of other databases on this page, renamed according their conventions.
* [http://sofacoustics.org/data/sofa_api_mo_test sofa_api_mo_test]: HRTFs resulting from tests of the [http://sourceforge.net/projects/sofacoustics/ SOFA API for Matlab/Octave]

== Other repositories ==

This is a list of other repositories providing HRTFs, BRIRs, and DRIRs available as SOFA files.

* '''ARI free-field HRTF database'''. HRTFs available for in-the-ear (ITE) and behind-the-ear (BTE) HRTFs. Link: https://www.oeaw.ac.at/isf/hrtf
* '''Example files''' created by the Matlab/Octave API. Link: http://tinyurl.com/sofaHRTFs
* [https://www.york.ac.uk/sadie-project/database.html SADIE]: Far-field HRTFs from the [https://www.york.ac.uk/sadie-project/ SADIE] project of over 20 human listeners. ''(Credit: Gavin Kearney, York)''

== Database missing? ==
If you want your/a SOFA database to be added please [https://www.sofaconventions.org/mediawiki/index.php/People_behind_SOFA contact Michael Mihocic or Piotr Majdak] for support.

User talk:G Yu

2022-07-18T08:10:40Z

Petibub: Welcome!

User:G Yu

2022-07-18T08:10:40Z

Petibub: Creating user page for new user.

Prof. Yu received his BSc degree (2002) in Mechanical from Huazhong Agriculture University, and and PhD degree (2009) in Acoustic from South Chia University of Technology. From 2002 to 2004, he worked as an Electronic and Testing Engineer in Companies. Prof. Yu joined the Acoustic lab, School of Physics and Optoelectronics in July 2009 as a Lecture and was promoted to Associate Professor and later Professor of Acoustics. His recent research includes Electronic Acoustics, Architecture Acoustics, Psychoacoustics, Spatial Audio, Binaural Hearing and Sound Signal Processing.

User talk:Tianshu Qu

2021-06-16T07:21:56Z

Petibub: Welcome!

User:Tianshu Qu

2021-06-16T07:21:56Z

Petibub: Creating user page for new user.

T.S. Qu got B.Eng. and M.Eng degree from Jilin University of Technology in 1993 and 1999. In 2002, he got Ph.D. degree from Jilin University. Then, he became a post-doctor of Peking University. In 2004, he finished the post-doctor work and became an assistant professor in Peking University. And now, he is an associate professor in Peking University. From 2011.3 to 2012.3, he went to Michigan State University as a visiting scholar. His principal interests are in acoustic signal processing, binaural auditory model and virtual sound.

User talk:PKU-IOA database

2021-06-16T07:21:27Z

Petibub: Welcome!

User:PKU-IOA database

2021-06-16T07:21:27Z

Petibub: Creating user page for new user.

User talk:3DJ

2021-06-02T09:17:10Z

Petibub: Welcome!

User:3DJ

2021-06-02T09:17:10Z

Petibub: Creating user page for new user.

Binaural audio enthusiast working on some projects:
https://kutt.it/Binaural - Binaural audio intro
https://kutt.it/BinauralDatabase - Binaural database (configurations, demos, ratings, guides, etc.)
https://kutt.it/BinauralDatabaseSearch - Binaural database search engine
https://kutt.it/BinauralDatabaseCatalog - Binaural database guide showcase
https://kutt.it/BinauralDatabaseAdd - Report and review binaural audio in games/programs/websites/music/movies/etc.
https://kutt.it/BinauralSoftware - Binaural audio software
https://kutt.it/BinauralHRTF - Binaural profile (HRTF) sample database for comparison
https://kutt.it/BinauralResources - Misc. resources
https://kutt.it/BinauralExperiments - Binaural audio experiments

Files

2021-02-15T09:27:03Z

Petibub:

Files

2020-12-04T10:09:07Z

Petibub:

User talk:Davicarvalho

2020-10-13T13:14:26Z

Petibub: Welcome!

User:Davicarvalho

2020-10-13T13:14:26Z

Petibub: Creating user page for new user.

Acoustical Engineering undergrad at UFSM - Brazil

SOFA (Spatially Oriented Format for Acoustics)

2020-09-18T16:06:34Z

Petibub:

SOFA is a file format for storing [http://en.wikipedia.org/wiki/Spatial_sound spatially] oriented acoustic data like [http://en.wikipedia.org/wiki/Head-related_transfer_function head-related transfer functions (HRTFs]) and binaural or spatial room [http://en.wikipedia.org/wiki/Impulse_response impulse responses] (BRIRs, SRIRs). SOFA has been standardized by the [http://aes.org Audio Engineering Society (AES)] as [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015]. This website aims at providing SOFA-relevant information.
* [[General information on SOFA]]
* [[SOFA specifications]]

SOFA conventions are designed for a consistent description of data stored in SOFA. The aim is the exchange of the data between researches and users. For each conventions, data exist from corresponding measurement setups and its description has been accepted by the peer group. Suggestions for new SOFA conventions and additions to existing ones are highly welcome.
* [[SOFA conventions]]

List of repositories with SOFA files containing [http://en.wikipedia.org/wiki/Head-related_transfer_function HRTFs], PRTFs, BRIRs, and DRIRs measured by different researchers. ''' New: CHEDAR: Numerically calculated HRTFs (with 3D meshes provided)!'''

* [[Files|Files (HRTFs, BRIRs, DRIRs, HpIRs)]]

SOFA files can be read and modified by software and application-programming interfaces (APIs). ''' New: 3D Tune-In Toolkit and Anaglyph added!'''
* [[Software and APIs]]

SOFA is result of the work of many people from various institutions.
* [[People behind SOFA]]

The SOFA project got awarded with the Reproducibility in Audio and Music Research Prize 2013 [http://soundsoftware.ac.uk/rr-prize-winner-announcement].

== News history ==
* 04.06.2020: CHEDAR, numerically calculated HRTFs added (Credit: Slim Ghorbal, France)
* 07.04.2020: Applications 3D Tune-In Toolkit and Anaglyph added
* 22.01.2020: Widespread (PRTFs and pinna meshes) of 1005 listeners added (Credits: Corentin Guezonoc, CentraleSupélec, Cesson-Sévigné, France).
* 15.10.2019: Head-gear HRTFs of a mannequin added (Credits: Christoph Pörschmann, Technische Hochschule Köln, Germany)
* 04.07.2019: SOFA for Max: object collection for Max added (Credits: Dale Johnson and Hyunkook Lee, APL, HUD, UK)
* 18.06.2019: SOFASonix: Lightweight SOFA API for Python added (Credits: Ioseb Laghidze, Joey Lag, ISVR, Southhampton, UK)
* 28.05.2019: pysofaconventions, a SOFA API for Python added (Credits: Andrés Pérez-López, UPF/Eurecat, Spain)
* 06.09.2018: pySOFA, a SOFA API for Python added (Credits: Jörg Encke, TUM, Munich)
* 05.09.2018: DRIRs from THK added (Credits: Johannes Arend, Tim Lübeck)
* 11.06.2018: DirPat (Application) added (Credits: Franz Zotter and the [https://opendata.iem.at/projects/dirpat/ DirPat] team)
* 13.11.2017: SBSBRIRs added (Credits: Chris Pike)
* 19.07.2017: Aachen HRTF database added (Credits: Janina Fels)
* 13.07.2017: WebSofa added to the Software section (Credits: Christian-W. Budde)
* 25.05.2017: HRTFs and HpIRs of FABIAN from TU-Berlin added (Credits: Fabian Brinkmann)
* 21.11.2016: Near-field HRTFs from the Fachhochschule Köln with 5 different measurement distances
* 16.08.2016: Large update of the Oldenburg BRIRs.
* 05.03.2015: AES standardization process completed. SOFA 1.0 is now [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015].
* 22.10.2014: Files added: HpIRs from the BT-DEI database provided (Credits: Michele Geronazzo, Italy)
* 15.10.2014: Discussion: New datatype "SOS" proposed
* 03.10.2014: Files added: Headphone IRs (HpIRs) from the ARI database for over 100 human listeners provided
* 11.08.2014: Conventions: SimpleHeadphoneIR 0.1 completed
* 23.05.2014: Files added: ARI (ARTIFICIAL), HRTFs of mannequins (dummy heads) measured at ARI using the same setup as for human listeners
* 08.04.2014: Files added: ARI B, files with low-frequency content for Hifi listening experience.
* 25.03.2014: Files updated: Update to SOFA 0.6
* 20.03.2014: SOFA 0.6
* 21.03.2014: Files added: RIEC Far-field HRTFs from the RIEC database (Credits: Kajni Watanabe, Japan)
* 20.03.2014: Conventions: SimpleFreeFieldHRIR 0.4 completed
* 27.11.2013: Files added: Near-field HRTFs from SCUT database of the KEMAR (Credits: Bosun Xie, China)
* 18.11.2013: Files added: HRTFs of the dummy-head Neumann K100, gapless and high spatial resolution (Credits: Benjamin Bernschütz)
* 30.08.2013: SOFA 0.5
* 29.08.2013: Files added: DRIRs from Oldenburg. Recordings in an office under several conditions (Credits: Stephan Ewert)
* 29.06.2013: Conventions: GeneralFIR and GeneralTF completed
* 21.06.2013: Files added: ARI, LISTEN, CIPIC, MIT KEMAR, TU-Berlin
* 20.08.2013: Conventions: SimpleFreeFieldHRIR 0.3 proposed
* 17.05.2013: SOFA 0.3
* 17.05.2013: Website released

SOFA conventions

2020-09-18T16:06:08Z

Petibub:

SOFA conventions specify the description of data and metadata for a particular kind of measured data.

This is important in order to meet the different requirements coming from different application fields, specified. For example, description of HRTFs, BRIRs, and DRIRs requires different metadata. Also, some applications may prefer to see the data stored in a different way. These conventions, once approved by the peer group are defined in SOFA conventions.

Specification of conventions are displayed in tables using the following legend:

* '''Name''': the name of the metadata
** A colon: the metadata is an attribute
*** "GLOBAL:": the metadata is a global attribute
*** "X:Y": the metadata is an attribute Y of the variable X
** No colon: the metadata is a variable
** Data.X: the metadata is structured within the data
* '''Default''': default value for the metadata
** An asterisk (*): special handling required, mentioned in the column Comment
* '''Flags''':
** r: read-only, must be the default value
** m: mandatory, must be saved in the file
* '''Dimensions''': dimensions of the metadata (see [[SOFA specifications]] for more explanations)
** lower case: the variable size in that dimension determines the dimension size in the file
** upper case: variable must be of that dimension (or one of these dimensions)

== Standardized SOFA conventions ==

Standardized SOFA conventions are those which have been standardized by the AES.

As with AES69-2015 (SOFA 1.0), we have:
* [[GeneralFIR]]: General convention with FIR as DataType (no restrictions but DataType)
* [[GeneralTF]]: General convention with TF as DataType (no restrictions but DataType)
* [[SimpleFreeFieldHRIR]]: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.

As with AES69-2020 (SOFA 2.0), we are currently working on:
* [[GeneralFIR-E]]: General convention with FIR-E as DataType (no restrictions but DataType). GeneralFIR-E is the standardized version of the previously proposed GeneralFIR convention. It extends GeneralFIR by having Emitter as an explicit dimension in the data.
* [[GeneralTF-E]]: General convention with TF-E as DataType (no restrictions but DataType). GeneralTF-E extends GeneralTF by having Emitter as an explicit dimension in the data.
* [[General]]: General convention with any datatype (no restrictions at all).
* [[SimpleFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is TF.
* [[SimpleFreeFieldHRSOS]]: Free-field HRTFs stored as second-order sections, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is SOS.
* [[SHFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions in the spherical-harmonics domain, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRTF, the only difference is that the HRTFs are in a spatially continuous representation.
* [[SimpleFreeFieldDirectivityTF]]: Convention for storing directivities of musical instruments or loudspeakers at spatial discrete points in the frequency domain. SimpleFreeFieldDirectivityTF is the standardized version of the previously proposed FreeFieldDirectivityTF and MusicalInstrumentDirectivityTF.
* [[SingleRoomSRIR]]: spatial room impulse responses (SRIRs) measured with an arbitrary number of receivers (R>1, such as a microphone array) and an omnidirectional source (E=1) in a single room. SingleRoomSRIR is the standardized version of the previously proposed [[SingleRoomDRIR]].
* [[SingleRoomMIMOIR]]: SRIRs measured with a compact listener containing an arbitrary number of receivers (R>1, such as a compact microphone array) and a compact source containing an arbitrary number of receivers (E>1, such as a multi-emitter loudspeaker) for multiple positions and/or orientations of the listener and/or source, in a single room.
* [[SimpleHeadphoneIR]]: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.

Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.

==Stable SOFA conventions==
Stable SOFA conventions are those for which SOFA files are publicly available and can be read/modified by at least one publicly available software package.
* [[MultiSpeakerBRIR]]: binaural room impulse responses (BRIRs) measured with an arbitrary number of ''emitters'' (such as a loudspeaker array).

These conventions, when used often and widely, can be proposed for standardization to the AES.

==Proposed SOFA conventions==

Proposed SOFA conventions are those being currently discussed and considered as work in progress. If you would like to propose a new convention, consider the following rules:
* Data must exist (do not foresee the future)
* Data can not be described by existing SOFA conventions
* Relevant information about the data available

There are currently no proposed conventions.

== Ideas for future conventions ==

Here we list the suggestions and feedback from the peer group:
* Include anthropometric data
* Crosstalk cancellation filters
* Include calibration data from the measurement
* Include room pictures

Please use the "Discussion" function to discuss these topics.

==Deprecated SOFA conventions==

These conventions are deprecated because their proposal has changed or they have been standardized under different name. They are listed here for the sake of completeness only. When reading a SOFA file with a deprecated convention, convert to that stated below:
* [[FreeFieldDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[MusicalInstrumentDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[SimpleBRIR]]: use [[MultiSpeakerBRIR]] instead.
* [[GeneralFIRE]]: use [[GeneralFIR-E]] instead.
* [[SimpleFreeFieldTF]]: use [[SimpleFreeFieldHRTF]] instead.
* [[SimpleFreeFieldSOS]]: use [[SimpleFreeFieldHRSOS]] instead.
* [[SingleRoomDRIR]]: use [[SingleRoomSRIR]] instead.

We strongly discourage from saving data with those conventions.

== Feedback and Contribution ==

If you would like to contribute or propose new SOFA conventions:
* Send an e-mail to the [mailto:sofacoustics-devel@lists.sourceforge.net mailing list]. You don't have to be a member of the mailing list to send a message to the moderator.
* Go to one of the SOFA pages of your interest and use the "Discussion" for your contribution.
We appreciate your feedback!

SOFA specifications

2020-09-18T16:05:48Z

Petibub:

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==

SOFA 1.0 supports two coordinates systems: [https://en.wikipedia.org/wiki/Cartesian_coordinate_system Cartesian] and spherical in the azimuth/elevation representation.

[[file:Coordinate_system.png]]

SOFA 2.0 adds a spatially ''continuous'' representation of receivers by means of the coordinate type 'spherical harmonics'. To this end, data depending on the position of the receivers are stored as real-valued spherical harmonic coefficients along the dimension R. Thus, each subset of data for a specific R corresponds not to a specific receiver position, but to a specific spherical harmonic order and degree. Along the dimension R , the data are stored in the [https://en.wikipedia.org/wiki/Ambisonic_data_exchange_formats#ACN ACN order]. The spatially continuous representation is indicated by the ReceiverPosition_Type of 'Spherical Harmonics', ReceiverPosition_Units is 'metre', and the ReceiverPosition stores the information about the radius only.

SOFA 2.0 further adds the spatially continuous representation of emitters, which uses the same scheme as that of receivers.

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 2.0) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 2.0) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-09-18T16:05:23Z

Petibub: /* Coordinate system */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==

SOFA 1.0 supports two coordinates systems: [https://en.wikipedia.org/wiki/Cartesian_coordinate_system Cartesian] and spherical in the azimuth/elevation representation.

[[file:Coordinate_system.png]]

SOFA 2.0 adds a spatially ''continuous'' representation of receivers by means of the coordinate type 'spherical harmonics'. To this end, data depending on the position of the receivers are stored as real-valued spherical harmonic coefficients along the dimension R. Thus, each subset of data for a specific R corresponds not to a specific receiver position, but to a specific spherical harmonic order and degree. Along the dimension R , the data are stored in the [https://en.wikipedia.org/wiki/Ambisonic_data_exchange_formats#ACN ACN order]. The spatially continuous representation is indicated by the ReceiverPosition_Type of 'Spherical Harmonics', ReceiverPosition_Units is 'metre', and the ReceiverPosition stores the information about the radius only.

SOFA 2.0 further adds the spatially continuous representation of emitters, which uses the same scheme as that of receivers.

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA conventions

2020-09-10T11:25:49Z

Petibub: /* Standardized SOFA conventions */

SOFA conventions specify the description of data and metadata for a particular kind of measured data.

This is important in order to meet the different requirements coming from different application fields, specified. For example, description of HRTFs, BRIRs, and DRIRs requires different metadata. Also, some applications may prefer to see the data stored in a different way. These conventions, once approved by the peer group are defined in SOFA conventions.

Specification of conventions are displayed in tables using the following legend:

* '''Name''': the name of the metadata
** A colon: the metadata is an attribute
*** "GLOBAL:": the metadata is a global attribute
*** "X:Y": the metadata is an attribute Y of the variable X
** No colon: the metadata is a variable
** Data.X: the metadata is structured within the data
* '''Default''': default value for the metadata
** An asterisk (*): special handling required, mentioned in the column Comment
* '''Flags''':
** r: read-only, must be the default value
** m: mandatory, must be saved in the file
* '''Dimensions''': dimensions of the metadata (see [[SOFA specifications]] for more explanations)
** lower case: the variable size in that dimension determines the dimension size in the file
** upper case: variable must be of that dimension (or one of these dimensions)

== Standardized SOFA conventions ==

Standardized SOFA conventions are those which have been standardized by the AES.

As with AES69-2015 (SOFA 1.0), we have:
* [[GeneralFIR]]: General convention with FIR as DataType (no restrictions but DataType)
* [[GeneralTF]]: General convention with TF as DataType (no restrictions but DataType)
* [[SimpleFreeFieldHRIR]]: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.

As with AES69-2020 (SOFA 1.1), we are currently working on:
* [[GeneralFIR-E]]: General convention with FIR-E as DataType (no restrictions but DataType). GeneralFIR-E is the standardized version of the previously proposed GeneralFIR convention. It extends GeneralFIR by having Emitter as an explicit dimension in the data.
* [[GeneralTF-E]]: General convention with TF-E as DataType (no restrictions but DataType). GeneralTF-E extends GeneralTF by having Emitter as an explicit dimension in the data.
* [[General]]: General convention with any datatype (no restrictions at all).
* [[SimpleFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is TF.
* [[SimpleFreeFieldHRSOS]]: Free-field HRTFs stored as second-order sections, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is SOS.
* [[SHFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions in the spherical-harmonics domain, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRTF, the only difference is that the HRTFs are in a spatially continuous representation.
* [[SimpleFreeFieldDirectivityTF]]: Convention for storing directivities of musical instruments or loudspeakers at spatial discrete points in the frequency domain. SimpleFreeFieldDirectivityTF is the standardized version of the previously proposed FreeFieldDirectivityTF and MusicalInstrumentDirectivityTF.
* [[SingleRoomSRIR]]: spatial room impulse responses (SRIRs) measured with an arbitrary number of receivers (R>1, such as a microphone array) and an omnidirectional source (E=1) in a single room. SingleRoomSRIR is the standardized version of the previously proposed [[SingleRoomDRIR]].
* [[SingleRoomMIMOIR]]: SRIRs measured with a compact listener containing an arbitrary number of receivers (R>1, such as a compact microphone array) and a compact source containing an arbitrary number of receivers (E>1, such as a multi-emitter loudspeaker) for multiple positions and/or orientations of the listener and/or source, in a single room.
* [[SimpleHeadphoneIR]]: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.

Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.

==Stable SOFA conventions==
Stable SOFA conventions are those for which SOFA files are publicly available and can be read/modified by at least one publicly available software package.
* [[MultiSpeakerBRIR]]: binaural room impulse responses (BRIRs) measured with an arbitrary number of ''emitters'' (such as a loudspeaker array).

These conventions, when used often and widely, can be proposed for standardization to the AES.

==Proposed SOFA conventions==

Proposed SOFA conventions are those being currently discussed and considered as work in progress. If you would like to propose a new convention, consider the following rules:
* Data must exist (do not foresee the future)
* Data can not be described by existing SOFA conventions
* Relevant information about the data available

There are currently no proposed conventions.

== Ideas for future conventions ==

Here we list the suggestions and feedback from the peer group:
* Include anthropometric data
* Crosstalk cancellation filters
* Include calibration data from the measurement
* Include room pictures

Please use the "Discussion" function to discuss these topics.

==Deprecated SOFA conventions==

These conventions are deprecated because their proposal has changed or they have been standardized under different name. They are listed here for the sake of completeness only. When reading a SOFA file with a deprecated convention, convert to that stated below:
* [[FreeFieldDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[MusicalInstrumentDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[SimpleBRIR]]: use [[MultiSpeakerBRIR]] instead.
* [[GeneralFIRE]]: use [[GeneralFIR-E]] instead.
* [[SimpleFreeFieldTF]]: use [[SimpleFreeFieldHRTF]] instead.
* [[SimpleFreeFieldSOS]]: use [[SimpleFreeFieldHRSOS]] instead.
* [[SingleRoomDRIR]]: use [[SingleRoomSRIR]] instead.

We strongly discourage from saving data with those conventions.

== Feedback and Contribution ==

If you would like to contribute or propose new SOFA conventions:
* Send an e-mail to the [mailto:sofacoustics-devel@lists.sourceforge.net mailing list]. You don't have to be a member of the mailing list to send a message to the moderator.
* Go to one of the SOFA pages of your interest and use the "Discussion" for your contribution.
We appreciate your feedback!

SOFA specifications

2020-09-07T14:49:53Z

Petibub: /* Coordinate system */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==

SOFA 1.0 supports two coordinates systems: [https://en.wikipedia.org/wiki/Cartesian_coordinate_system Cartesian] and spherical in the azimuth/elevation representation.

[[file:Coordinate_system.png]]

SOFA 1.1 adds a spatially ''continuous'' representation of receivers by means of the coordinate type 'spherical harmonics'. To this end, data depending on the position of the receivers are stored as real-valued spherical harmonic coefficients along the dimension R. Thus, each subset of data for a specific R corresponds not to a specific receiver position, but to a specific spherical harmonic order and degree. Along the dimension R , the data are stored in the [https://en.wikipedia.org/wiki/Ambisonic_data_exchange_formats#ACN ACN order]. The spatially continuous representation is indicated by the ReceiverPosition_Type of 'Spherical Harmonics', ReceiverPosition_Units is 'metre', and the ReceiverPosition stores the information about the radius only.

SOFA 1.1 further adds the spatially continuous representation of emitters, which uses the same scheme as that of receivers.

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-09-07T14:48:17Z

Petibub: /* Coordinate system */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==

SOFA 1.0 supports two coordinates systems: [https://en.wikipedia.org/wiki/Cartesian_coordinate_system Cartesian] and spherical in the azimuth/elevation representation.

[[file:Coordinate_system.png]]

SOFA 1.1 adds a spatially ''continuous'' representation of receivers by means of the coordinate type 'spherical harmonics'. To this end, data depending on the position of the receivers are stored as real-valued spherical harmonic coefficients along the dimension R. Thus, each subset of data for a specific R corresponds not to a specific receiver position, but to a specific spherical harmonic order and degree. Along the dimension R , the data are stored in the [https://en.wikipedia.org/wiki/Ambisonic_data_exchange_formats#ACN ACN order]. The spatially continuous representation is indicated by the ReceiverPosition_Type of 'Harmonic' and ReceiverPosition_Units of 'Spherical'. As the directional information is stored in the data, ReceiverPosition contains information about the radius represented in the spherical coordinate system of SOFA 1.0.

SOFA 1.1 further adds the spatially continuous representation of emitters, which uses the same scheme as that of receivers.

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-09-05T15:38:31Z

Petibub: /* Coordinate system */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==

SOFA 1.0 supports two coordinates systems: [https://en.wikipedia.org/wiki/Cartesian_coordinate_system Cartesian] and spherical in the azimuth/elevation representation.

[[file:Coordinate_system.png]]

SOFA 1.1 adds a spatially ''continuous'' representation of receivers by means of spherical harmonics. To this end, data depending on the position of the receivers are stored as real-valued spherical harmonic coefficients along the dimension R. Thus, each subset of data for a specific R corresponds not to a specific receiver position, but to a specific spherical harmonic order and degree. Along the dimension R , the data are stored in the [https://en.wikipedia.org/wiki/Ambisonic_data_exchange_formats#ACN ACN order]. The spatially continuous representation is indicated by the ReceiverPosition_Type of 'Harmonic' and ReceiverPosition_Units of 'Spherical'. As the directional information is stored in the data, ReceiverPosition contains information about the radius represented in the spherical coordinate system of SOFA 1.0.

SOFA 1.1 further adds the spatially continuous representation of emitters, which uses the same scheme as that of receivers.

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-09-05T15:29:54Z

Petibub: Spherical harmonics added

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==

SOFA 1.0 supports two coordinates systems: [https://en.wikipedia.org/wiki/Cartesian_coordinate_system Cartesian] and spherical in the azimuth/elevation representation.

[[file:Coordinate_system.png]]

SOFA 1.1 adds a spatially ''continuous'' representation of receivers (and emitters) by means of spherical harmonics. To this end, data depending on the position of the receivers (and emitters) are stored as real-valued spherical harmonic coefficients along the dimension R (and E, respectively). Thus, each subset of data for a specific R (and E, respectively) corresponds not to a specific receiver (and emitter, respectively) position, but to a specific spherical harmonic order and degree. Along the dimension R (and E, respectively), the data are stored in the [https://en.wikipedia.org/wiki/Ambisonic_data_exchange_formats#ACN ACN order].

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA conventions

2020-08-04T16:48:05Z

Petibub: /* Standardized SOFA conventions */

SOFA conventions specify the description of data and metadata for a particular kind of measured data.

This is important in order to meet the different requirements coming from different application fields, specified. For example, description of HRTFs, BRIRs, and DRIRs requires different metadata. Also, some applications may prefer to see the data stored in a different way. These conventions, once approved by the peer group are defined in SOFA conventions.

Specification of conventions are displayed in tables using the following legend:

* '''Name''': the name of the metadata
** A colon: the metadata is an attribute
*** "GLOBAL:": the metadata is a global attribute
*** "X:Y": the metadata is an attribute Y of the variable X
** No colon: the metadata is a variable
** Data.X: the metadata is structured within the data
* '''Default''': default value for the metadata
** An asterisk (*): special handling required, mentioned in the column Comment
* '''Flags''':
** r: read-only, must be the default value
** m: mandatory, must be saved in the file
* '''Dimensions''': dimensions of the metadata (see [[SOFA specifications]] for more explanations)
** lower case: the variable size in that dimension determines the dimension size in the file
** upper case: variable must be of that dimension (or one of these dimensions)

== Standardized SOFA conventions ==

Standardized SOFA conventions are those which have been standardized by the AES.

As with AES69-2015 (SOFA 1.0), we have:
* [[GeneralFIR]]: General convention with FIR as DataType (no restrictions but DataType)
* [[GeneralTF]]: General convention with TF as DataType (no restrictions but DataType)
* [[SimpleFreeFieldHRIR]]: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.

As with AES69-2020 (SOFA 1.1), we are currently working on:
* [[GeneralFIR-E]]: General convention with FIR-E as DataType (no restrictions but DataType). GeneralFIR-E is the standardized version of the previously proposed GeneralFIR convention. It extends GeneralFIR by having Emitter as an explicit dimension in the data.
* [[GeneralTF-E]]: General convention with TF-E as DataType (no restrictions but DataType). GeneralTF-E extends GeneralTF by having Emitter as an explicit dimension in the data.
* [[General]]: General convention with any datatype (no restrictions at all).
* [[SimpleFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is TF.
* [[SimpleFreeFieldHRSOS]]: Free-field HRTFs stored as second-order sections, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is SOS.
* [[SHFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions in the spherical-harmonics domain, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRTF, the only difference is that the HRTFs are in a spatially continuous representation.
* [[SimpleFreeFieldDirectivityTF]]: Convention for storing directivities of musical instruments or loudspeakers at spatial discrete points in the frequency domain. SimpleFreeFieldDirectivityTF is the standardized version of the previously proposed FreeFieldDirectivityTF and MusicalInstrumentDirectivityTF.
* [[SingleRoomSRIR]]: spatial room impulse responses (SRIRs) measured with an arbitrary number of receivers (R>1, such as a microphone array) and an omnidirectional source (E=1) in a single room. SingleRoomSRIR is the standardized version of the previously proposed SingleRoomDRIR.
* [[SingleRoomMIMOIR]]: SRIRs measured with a compact listener containing an arbitrary number of receivers (R>1, such as a compact microphone array) and a compact source containing an arbitrary number of receivers (E>1, such as a multi-emitter loudspeaker) for multiple positions and/or orientations of the listener and/or source, in a single room.
* [[SimpleHeadphoneIR]]: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.

Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.

==Stable SOFA conventions==
Stable SOFA conventions are those for which SOFA files are publicly available and can be read/modified by at least one publicly available software package.
* [[MultiSpeakerBRIR]]: binaural room impulse responses (BRIRs) measured with an arbitrary number of ''emitters'' (such as a loudspeaker array).

These conventions, when used often and widely, can be proposed for standardization to the AES.

==Proposed SOFA conventions==

Proposed SOFA conventions are those being currently discussed and considered as work in progress. If you would like to propose a new convention, consider the following rules:
* Data must exist (do not foresee the future)
* Data can not be described by existing SOFA conventions
* Relevant information about the data available

There are currently no proposed conventions.

== Ideas for future conventions ==

Here we list the suggestions and feedback from the peer group:
* Include anthropometric data
* Crosstalk cancellation filters
* Include calibration data from the measurement
* Include room pictures

Please use the "Discussion" function to discuss these topics.

==Deprecated SOFA conventions==

These conventions are deprecated because their proposal has changed or they have been standardized under different name. They are listed here for the sake of completeness only. When reading a SOFA file with a deprecated convention, convert to that stated below:
* [[FreeFieldDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[MusicalInstrumentDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[SimpleBRIR]]: use [[MultiSpeakerBRIR]] instead.
* [[GeneralFIRE]]: use [[GeneralFIR-E]] instead.
* [[SimpleFreeFieldTF]]: use [[SimpleFreeFieldHRTF]] instead.
* [[SimpleFreeFieldSOS]]: use [[SimpleFreeFieldHRSOS]] instead.
* [[SingleRoomDRIR]]: use [[SingleRoomSRIR]] instead.

We strongly discourage from saving data with those conventions.

== Feedback and Contribution ==

If you would like to contribute or propose new SOFA conventions:
* Send an e-mail to the [mailto:sofacoustics-devel@lists.sourceforge.net mailing list]. You don't have to be a member of the mailing list to send a message to the moderator.
* Go to one of the SOFA pages of your interest and use the "Discussion" for your contribution.
We appreciate your feedback!

SOFA specifications

2020-08-04T16:46:58Z

Petibub: /* FIRE (deprecated) */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==
[[file:Coordinate_system.png]]

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (SOFA 1.0, deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-08-04T16:46:42Z

Petibub: /* SOS (SOFA 1.1) */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==
[[file:Coordinate_system.png]]

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-08-04T16:46:25Z

Petibub: /* FIR (SOFA 1.0) */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==
[[file:Coordinate_system.png]]

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-08-04T16:46:18Z

Petibub: /* TF (SOFA 1.0) */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==
[[file:Coordinate_system.png]]

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-08-04T16:46:03Z

Petibub: /* SOS (proposed) */

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==
[[file:Coordinate_system.png]]

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (SOFA 1.1) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA specifications

2020-08-04T16:45:54Z

Petibub: FIR-E added, deprecated FIRE.

== Specifications ==

* SOFA 1.0 is reflected by the [http://www.aes.org/publications/standards/search.cfm?docID=99 AES69-2015] standard. It mostly corresponds to SOFA 0.6, which specs can be downloaded [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.6.pdf/download here]. A document with SOFA 1.0 specs is under preparation.

Older specs:
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.5.pdf/download Version 0.5: Download specifications]
* [[Proposal 0.4 | Version 0.4: Discussion on the specifications]] (closed)
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.3.pdf/download Version 0.3: Download specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.2.pdf/download Version 0.2: Specifications]
* [http://sourceforge.net/projects/sofacoustics/files/SOFA%20specs%200.1%20%28as%20of%20AES%202013%29.pdf/download Version 0.1: Specifications as presented at the AES Convention 2013 in Rom]

== Coordinate system ==
[[file:Coordinate_system.png]]

== Data Types ==

=== FIR (SOFA 1.0) ===

For storing impulse responses.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mRn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IR, MR||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== TF (SOFA 1.0) ===

Useful to describe a transfer function by a sparse number of frequencies. The guys from BEM simulations like it.

Note: the dimensional variable N is mandatory, it must be of dimension N, and must provide the frequency values.

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>TF</nowiki>||rm||||attribute||
|-
|Data.Real||<nowiki>0</nowiki>||m||mRn||double|| The real part of the complex spectrum
|-
|Data.Imag||<nowiki>0</nowiki>||m||MRN||double|| The imaginary part of the complex spectrum
|-
|N||<nowiki>0</nowiki>||m||N||double|| Frequency values
|-
|N_LongName||<nowiki>frequency</nowiki>||||||attribute||
|-
|N_Units||<nowiki>hertz</nowiki>||m||||attribute|| Unit of the values given in N
|}

=== SOS (proposed) ===

This DataType stores a filter as a broadband delay and an arbitrary number of second order sections (SOSs).

The transfer function H(z) of a filter can be described as:

<math>H(z) = \frac{B_1(z)}{A_1(z)} \cdot \frac{B_2(z)}{A_2(z)} \cdot ... \cdot \frac{B_p(z)}{A_p(z)}</math>

where <math>p</math> is the number of second order sections, <math>A(z)</math> is denominator representing the poles of a filter, and <math>B(z)</math> is numerator representing the zeros of a filter. Then, each SOS can be described as:

<math>B_i(z) = b_{i,0} + b_{i,1} z^{-1} + b_{i,2} z^{-2}</math>

<math>A_i(z) = a_{i,0} + a_{i,1} z^{-1} + a_{i,2} z^{-2}</math>

Note that usually, <math>A_i(z)</math> is normalized such that <math>a_{i,0} = 1</math>.

Thus, in the DataType SOS, a filter is represented by three mandatory variables:

* Data.SamplingRate: sampling rate used to describe the filter.
* Data.Delay: broadband delay (in samples resulting from SamplingRate). Note: Use Delay of zero when not used.used).
* Data.SOS: list of coefficients of all SOSs.
** Size: Data.SOS has the size of '''[ M R N ]''' with N as the total number of coefficients, thus an integer multiple of 6 corresponding to <math>6p</math>.
** Format of the list: Along the dimension N, the list goes like: <math>[ b_{1,0}\ b_{1,1}\ b_{1,2}\ a_{1,0}\ a_{1,1}\ a_{1,2}\ b_{2,0}\ b_{2,1}\ b_{2,2}\ a_{2,0}\ a_{2,1}\ a_{2,2}\ ... b_{p,0}\ b_{p,1}\ b_{p,2}\ a_{p,0}\ a{p,1}\ a_{p,2} ]</math> which corresponds to <math>[ B_1(z)\ A_1(z)\ B_2(z)\ A_2(z)\ ... B_p(z)\ A_p(z) ]</math>

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|Data.SOS||<nowiki>permute([0 0 0 1 0 0],[3 1 2])</nowiki>||m||mRn||double||Filter coefficients as SOS coefficients.
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the coefficients in Data.SOS and the delay in Data.Delay
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||MR||double||Broadband delay (in samples resulting from SamplingRate)
|}

=== FIR-E (SOFA 1.1) ===

FIR-E is based on FIR and is intended for storing impulse responses which depend on the emitter (E).

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIR-E</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

=== FIRE (deprecated) ===

FIRE is the proposed version of FIR-E. With FIR-E being standardized, we strongly discourage from using it, use FIR-E instead.

Note: Delay is mandatory (set to 0 if not used).

{| border="1"
!Name
!Default
!Flags
!Dimensions
!Type
!Comment
|-
|GLOBAL:DataType||<nowiki>FIRE</nowiki>||rm||||attribute||
|-
|Data.IR||<nowiki>0</nowiki>||m||mREn||double||Impulse responses
|-
|Data.SamplingRate||<nowiki>48000</nowiki>||m||I||double||Sampling rate of the samples in Data.IR
|-
|Data.SamplingRate:Units||<nowiki>hertz</nowiki>||m||||attribute||Unit of the sampling rate
|-
|Data.Delay||<nowiki>0</nowiki>||m||IRE, MRE||double||Additional delay of each IR (always in samples, i.e. units of N)
|}

SOFA conventions

2020-08-04T16:39:19Z

Petibub: deprecated conventions added

SOFA conventions specify the description of data and metadata for a particular kind of measured data.

This is important in order to meet the different requirements coming from different application fields, specified. For example, description of HRTFs, BRIRs, and DRIRs requires different metadata. Also, some applications may prefer to see the data stored in a different way. These conventions, once approved by the peer group are defined in SOFA conventions.

Specification of conventions are displayed in tables using the following legend:

* '''Name''': the name of the metadata
** A colon: the metadata is an attribute
*** "GLOBAL:": the metadata is a global attribute
*** "X:Y": the metadata is an attribute Y of the variable X
** No colon: the metadata is a variable
** Data.X: the metadata is structured within the data
* '''Default''': default value for the metadata
** An asterisk (*): special handling required, mentioned in the column Comment
* '''Flags''':
** r: read-only, must be the default value
** m: mandatory, must be saved in the file
* '''Dimensions''': dimensions of the metadata (see [[SOFA specifications]] for more explanations)
** lower case: the variable size in that dimension determines the dimension size in the file
** upper case: variable must be of that dimension (or one of these dimensions)

== Standardized SOFA conventions ==

Standardized SOFA conventions are those which have been standardized by the AES.

As with AES69-2015 (SOFA 1.0), we have:
* [[GeneralFIR]]: General convention with FIR as DataType (no restrictions but DataType)
* [[GeneralTF]]: General convention with TF as DataType (no restrictions but DataType)
* [[SimpleFreeFieldHRIR]]: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.

As with AES69-2015 (SOFA 1.1), we are currently working on:
* [[GeneralFIR-E]]: General convention with FIR-E as DataType (no restrictions but DataType). GeneralFIR-E is the standardized version of the previously proposed GeneralFIR convention. It extends GeneralFIR by having Emitter as an explicit dimension in the data.
* [[GeneralTF-E]]: General convention with TF-E as DataType (no restrictions but DataType). GeneralTF-E extends GeneralTF by having Emitter as an explicit dimension in the data.
* [[General]]: General convention with any datatype (no restrictions at all).
* [[SimpleFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is TF.
* [[SimpleFreeFieldHRSOS]]: Free-field HRTFs stored as second-order sections, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRIR, the only difference is the DataType, that is SOS.
* [[SHFreeFieldHRTF]]: Free-field HRTFs stored as transfer functions in the spherical-harmonics domain, measured with an omnidirectional source for a single listener. Based on SimpleFreeFieldHRTF, the only difference is that the HRTFs are in a spatially continuous representation.
* [[SimpleFreeFieldDirectivityTF]]: Convention for storing directivities of musical instruments or loudspeakers at spatial discrete points in the frequency domain. SimpleFreeFieldDirectivityTF is the standardized version of the previously proposed FreeFieldDirectivityTF and MusicalInstrumentDirectivityTF.
* [[SingleRoomSRIR]]: spatial room impulse responses (SRIRs) measured with an arbitrary number of receivers (R>1, such as a microphone array) and an omnidirectional source (E=1) in a single room. SingleRoomSRIR is the standardized version of the previously proposed SingleRoomDRIR.
* [[SingleRoomMIMOIR]]: SRIRs measured with a compact listener containing an arbitrary number of receivers (R>1, such as a compact microphone array) and a compact source containing an arbitrary number of receivers (E>1, such as a multi-emitter loudspeaker) for multiple positions and/or orientations of the listener and/or source, in a single room.
* [[SimpleHeadphoneIR]]: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.

Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.

==Stable SOFA conventions==
Stable SOFA conventions are those for which SOFA files are publicly available and can be read/modified by at least one publicly available software package.
* [[MultiSpeakerBRIR]]: binaural room impulse responses (BRIRs) measured with an arbitrary number of ''emitters'' (such as a loudspeaker array).

These conventions, when used often and widely, can be proposed for standardization to the AES.

==Proposed SOFA conventions==

Proposed SOFA conventions are those being currently discussed and considered as work in progress. If you would like to propose a new convention, consider the following rules:
* Data must exist (do not foresee the future)
* Data can not be described by existing SOFA conventions
* Relevant information about the data available

There are currently no proposed conventions.

== Ideas for future conventions ==

Here we list the suggestions and feedback from the peer group:
* Include anthropometric data
* Crosstalk cancellation filters
* Include calibration data from the measurement
* Include room pictures

Please use the "Discussion" function to discuss these topics.

==Deprecated SOFA conventions==

These conventions are deprecated because their proposal has changed or they have been standardized under different name. They are listed here for the sake of completeness only. When reading a SOFA file with a deprecated convention, convert to that stated below:
* [[FreeFieldDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[MusicalInstrumentDirectivityTF]]: use [[SimpleFreeFieldDirectivityTF]] instead.
* [[SimpleBRIR]]: use [[MultiSpeakerBRIR]] instead.
* [[GeneralFIRE]]: use [[GeneralFIR-E]] instead.
* [[SimpleFreeFieldTF]]: use [[SimpleFreeFieldHRTF]] instead.
* [[SimpleFreeFieldSOS]]: use [[SimpleFreeFieldHRSOS]] instead.
* [[SingleRoomDRIR]]: use [[SingleRoomSRIR]] instead.

We strongly discourage from saving data with those conventions.

== Feedback and Contribution ==

If you would like to contribute or propose new SOFA conventions:
* Send an e-mail to the [mailto:sofacoustics-devel@lists.sourceforge.net mailing list]. You don't have to be a member of the mailing list to send a message to the moderator.
* Go to one of the SOFA pages of your interest and use the "Discussion" for your contribution.
We appreciate your feedback!