Dear Marc, Spatial acoustic data is typically described by spatial acoustic transfer functions. AES69 describes a format for storing spatial acoustic data with a focus on interchangeability and extensibility and provides a basis for a wider generalized interchange of space-related audio data. It allows to store, e.g., room impulse responses measured with microphone arrays and loudspeaker arrays.
AES69/SOFA is thus not limited to HRTF/HRIR data. There is no preference on binaural listening, but it all started from a discussion on sharing HRTF data in between research labs. What is the difference between AES69 and SOFA: AES69 builds upon SOFA. It consists of “general specifications” and “conventions”. Conventions define recommendations on the naming of AES69 attributes, variables, and dimensions for discipline-specific data structures, that is particular measurement setups. In other standards a set of “conventions" is often referred to as a “profile”. New conventions are discussed on the SOFA website. When a new convention is considered to be stable enough, it will be added to the AES69 standard through the normal revision process. The current version of AES69 standardizes — The frequency domain representation of head-related transfer functions (HRTFs); — The time domain representation of HRTFs, that is head-related impulse responses (HRIRs); and — The time domain representation of HRTFs measured in reverberant spaces, that is binaural room impulse responses (BRIRs). We hope that we soon can add the following conventions to the standard: — The Quadrature Mirror Filter (QMF) domain representation of free-field HRTFs, that is the set of QMF parameters; or, even more generally, — The time domain representation of spatiotemporal room impulse responses, that is directional room impulse responses (DRIRs); and — The modal representation of the 3-D wave field, that is the spherical harmonics coefficients of the incoming/outgoing wave field. In our research lab, we are currently using an alpha version of a SOFA convention for storing MIMO room impulse responses that were measured with a 32-channel spherical loudspeaker array and a 64-channel spherical microphone array. These data can be then represented in various formats, such as the room impulse responses for each transmission channel (i.e. the transfer paths between each loudspeaker and each microphone) or the spherical harmonics coefficients of emitted and received wave fields, respectively. Please note that AES69 is a “spatial acoustic” and not a “spatial audio” format. You could of course use AES69/SOFA to store multichannel audio data, but I would recommend using more convenient multichannel audio data file formats such us broadcast WAV. I hope that this answers your questions? Kind regards, Markus > On 16 mars 2015, at 00:16, Marc Lavallée <m...@hacklava.net> wrote: > > Hi Mr. Noisternig. > > At first glance, this data file format is about binaural measurement > and rendering, and not about multi-channel based auditory scene > representation. I don't have access to the AES library, but the SOFA > specs are freely available, and I suppose the standard is based on the > specs. > > Even as a hobbyist, I can understand its usefulness, but why is it > named "spatial acoustic", without a reference to binaural listening? It > is for marketing reasons, based on the predominance of headphone > listening? > > -- > Marc > > On Sun, 15 Mar 2015 16:13:47 +0100, Markus Noisternig wrote: >> Dear Sursounders, >> >> We are pleased to announce the recent publication of the AES69-2015 >> standard for file exchange - Spatial acoustic data file format. See >> also the AES press release at http://www.aes.org/press/?ID=293 >> <http://www.aes.org/press/?ID=293> >> >> The new AES69-2015 standard defines a file format to exchange >> space-related acoustic data in various forms. These include HRTF, as >> well as directional room impulse responses (DRIR). The format is >> designed to be scalable to match the available rendering process and >> to be sufficiently flexible to include source materials from >> different databases. >> >> This project was developed in AES Standards Working Group SC-02-08 >> and standardizes the Spatially-oriented format for acoustics (SOFA), >> which aims at storing and transmitting any transfer-function data >> measured with microphone arrays and loudspeaker arrays. See >> http://www.sofaconventions.org/ <http://www.sofaconventions.org/> for >> further information and ongoing format discussions. >> >> Open source application-programming interfaces (API) for Matlab, >> Octave, and C++ are available online at >> http://sourceforge.net/projects/sofacoustics/ >> <http://sourceforge.net/projects/sofacoustics/> >> >> All the best, >> >> Markus and Piotr >> >> >> -- >> Markus Noisternig >> Acoustics and Cognition Research Group >> IRCAM, CNRS, Sorbonne Universities, UPMC >> Paris, France >> >> Piotr Majdak >> Psychoacoustics and Experimental Audiology >> Acoustics Research Institute >> Austrian Academy of Sciences >> Vienna, Austria >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: >> <https://mail.music.vt.edu/mailman/private/sursound/attachments/20150315/e3764123/attachment.html> >> _______________________________________________ Sursound mailing list >> Sursound@music.vt.edu >> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe >> here, edit account or options, view archives and so on. > > _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
