SOFA - Spatially Oriented Format for Acoustics

SOFA is a file format for reading, saving, and describing spatially oriented data of acoustic systems.

Examples of data we consider are head-related transfer functions (HRTFs), binaural room impulse responses (BRIRs), multichannel measurements such as done with microphone arrays, or directionality data of loudspeakers.

The format specification is the major focus of SOFA, but we also aim in providing toolboxes for reading and writing the data in SOFA. For more information on the format specifications and available data, see http://www.sofaconventions.org/.

This project implements a reference toolbox for SOFA: The SOFA Toolbox.

SOFA Toolbox 2.x implements SOFA versions 2.x. The SOFA Toolbox has been previously known as the SOFA API_MO, which supported SOFA versions up to 1.x.

Downloads

Current releases of SOFA Toolbox can be found on SourceForge.

Note:

• The SOFA Toolbox 2.1 is the succeeding release version of SOFA API M/O version 1.1.3. It supports SOFA 2.1 as known as AES69-2022.
• The SOFA Toolbox 2.0 has never been released.

Usage

Matlab/Octave

In order to use SOFA with Matlab or Octave add its SOFAtoolbox folder to your search paths. After that you can play around with your acoustic measurements as shown by the following example which uses a HRTF measurement.

% Start SOFA
SOFAstart;

%% put your information here:
hrtf = SOFAload('path/to_your/HRTF.sofa');
soundInput = audioread('path/to_your/fancy_audio_file.wav');

% Display some information about the impulse response
SOFAinfo(hrtf);
% Plot a figure with the measurement setup
SOFAplotGeometry(hrtf);
% Have a look at the size of the data
disp(['size [MxRxN]: ' num2str(size(hrtf.Data.IR))])
% Calculate the source position from a listener point of view
apparentSourceVector = SOFAcalculateAPV(hrtf);
% Listen to the HRTF with azimuth of -90°
apparentSourceVector(91, 1)
SOFAplotGeometry(hrtf, 91);
soundOutput = [conv(squeeze(hrtf.Data.IR(91, 1, :)), soundInput) ...
               conv(squeeze(hrtf.Data.IR(91, 2, :)), soundInput)];
sound(soundOutput, hrtf.Data.SamplingRate);