at Quality and Usability Lab
A new release of the Sound Field Analysis Toolbox (SOFiA) is available! This release includes a number of bugfixes and extensions:
SOFiA can be downloaded here http://code.google.com/p/sofia-toolbox/.
Tags: SOFiA, sound field analysis, spherical microphone array
I proudly announce that some time ago, I submitted the manuscript of a monography on sound field synthesis to Springer who will publish it under the title Analytic Methods of Sound Field Synthesis in spring 2012. You can find the official announcement here.
The book is not only a mere copy-and-paste of our papers. All our own work has been significantly enhanced in didactical terms and, of course, all relevant works of other authors and a considerable amount of previously unpublished material are included. Besides the physical fundamentals and spatial discretization (e.g., spatial aliasing), extensive discussions of various applications of sound field synthesis such as moving virtual sound sources, focused virtual sound sources, etc. and a variety of practical aspects are discussed. I have also put some effort in clarifying the relationship between Ambisonics and Wave Field Synthesis.
MATLAB/Octave scripts for all simulations contained in the book will be provided at http://www.soundfieldsynthesis.org.
Tags: focused sources, higher order Ambisonics, local sound field synthesis, sound field synthesis, spatial sampling, spectral division method, wave field synthesis
We have published a tutorial and firmware which allows to put together a low-cost Attitude and Heading Reference System (AHRS) that can be used as a head-tracker for virtual acoustics. A wired version of the tracker (connected via USB), as well as a wireless version (using Bluetooth) can be realized quite simple using comercially available hardware. The tracker is based on the Arduino-compatible “9DOF Razor IMU” board by SparkFun, which contains a 3-axis gyroscope/accelerometer/magnetometer and a microcontroller to do the sensor fusion.
Open source AHRS / head-tracking using SparkFun 9DOF Razor IMU (via USB or Bluetooth) from Spatial Audio Research on Vimeo.
The next release of the SoundScape Renderer (SSR) will support the tracker.
Tags: 9DOF tracker, head-tracker, SoundScape Renderer, virtual acoustics
Spherical microphone arrays and sound field decomposition using spherical harmonics is a well established technique for the analysis of sound fields, room acoustics or spatial audio recording applications. The Sound Field Analysis Toolbox (SOFiA) provides a MATLAB toolbox for the analysis of sound fields using data from spherical microphone arrays. It is freely available under the GNU GPL v3 license. For the evaluation of SOFiA, exemplary datasets from a VariSphear scanning array system are available under the Creative Commons license.
SOFiA can be downloaded here http://code.google.com/p/sofia-toolbox/
An overview of the SOFiA processing chain as well as a closer discussion of selected details can be found in the paper
B. Bernschütz, C. Pörschmann, S. Spors, and S. Weinzierl. SOFiA – Sound field analysis toolbox. In International Conference on Spatial Audio, Detmold, Germany, November 2011. [PDF]
Tags: room acoustics, SOFiA, sound field analysis, spherical microphone array
If you want to use the RME MADIface on Linux, it probably doesn’t work right away.
The latest version of ALSA (1.0.24) – which is probably already installed on your computer – is from January 2011. However, there was a lot of activity and bug-fixing going on since February. So you won’t have all the good stuff and a few things won’t work at all.
Especially, we couldn’t use the sound card in slave mode, and even in master mode a few sample rates just didn’t work. And, what’s really sad, the hdspmixer didn’t work.
But fear not, there is still hope!
That’s what we did:
Download the newest and freshest alsa-driver package from here: http://www.alsa-project.org/snapshot/.
Extract the package somewhere, and compile the thing:
tar xvjf /path/to/alsa-driver-1.0.24.88.gb41c8.1877.ga1e0a.tar.bz2 cd alsa-driver-1.0.24.88.gb41c8.1877.ga1e0a ./gitcompile
You may need a few development packages from your Debian (or whatever you are using) repository (maybe build-essentials, autoconf, …).
And then, as root, install everything:
make install
And that’s it! After re-booting (or restarting the relevant services if you know what those are …) everything should work. You can set the sync-options with alsamixer and you can also use the hdspmixer.
Of course, all this will be obsolete once the new ALSA version 1.0.25 (or whatever comes after 1.0.24) will be released as Debian (or whatever you are using) package.
Tags: linux, tips & tricks
Below you will find audio examples for the paper
Jens Ahrens and Sascha Spors: “Two Physical Models for Spatially Extended Virtual Sound Sources”, 131st Convention of the AES, New York City, NY, USA 2011 [ pdf ]
Download the zipped package, which contains the input signal as well as the signals evoked by two line sources (i.e., 2.5D approximations of two planar sources) vibrating in complex modes. One source has length 4 m and the other one has length 0.5 m. All other parameters are explained in Sec. 4.2 of the paper. You may listen with headphones as well as with loudspeakers since the audio examples give only a first impression of the results and are not formal.
The timetable for the International Conference on Spatial Audio 2011 in Detmold/Germany is now online:
The conference emphasizes the scientific and technical aspects of spatial audio, but a number of workshops and presentations will be devoted to the artistic and esthetic possibilities and challenges as well.
In addition to five structured sessions on various spatial audio topics, the conference will feature installations of WFS + Height, Auro-3D, Binaural and Higher-order Ambisonic systems. During a three-day recording session last week totalling more than 140 microphone signals, we have recorded several chamber music ensembles simultaneously for all those methods and will offer conference participants a first-hand opportunity for comparison.
Complementing the two fixed WFS installations available in Detmold, an additional temporary 40-speaker setup will be rigged for WFS and Higher-order Ambisonics reproduction, and one seminar room will be equipped for 9+2 channel Auro-3D playback.
Registration is now open, and I’d be delighted to see you in Detmold in November!
This announcement has been provided by Jörn Nettingsmeier
The new release 0.3.2 (Spinet) of the SoundScape Renderer (SSR) is available for download. This release contains a number of bugfixes and includes the source code of the Android SSR remote control. Thanks to all of you who have reported bugs. We encurage all users to send bug reports, usage reports and feature requests to SoundScapeRenderer@telekom.de. You can also send us your (example) scenes or content you have produced with the SSR. First examples provided by Stefan Greuel and Philipp Stade can be downloaded here.
The SSR development team
The SoundScape Renderer (SSR) is a versatile software framework for real-time spatial audio rendering. The modular system architecture allows the use of arbitrary rendering methods, e.g. Wave Field Synthesis, Higher-Order Ambisonics, Vector Base Amplitude Panning and binuaral techniques. The SSR is currently available for Linux and OS X. It has been released as open source software under the GPL.
Tags: Android, audio examples, SoundScape Renderer
The International Conference on Spatial Audio 2011 takes place from November 10 to 13 at Detmold University of Music. This expert‘s summit will examine current systems for multichannel audio reproduction and complementing recording techniques, and discuss their respective strengths and weaknesses. Wavefield synthesis systems, a higher-order Ambisonics array, as well as 5.1/7.1 installations in diverse acoustic environments will be available for comparative listening tests during the conference. Structured plenary talks, paper and poster sessions will revisit fundamentals and present latest research. A series of workshops will be dedicated to practical implementations of spatial sound capture and playback methods, and their esthetic and psychoacoustical implications for music perception. Concerts that include music specially arranged for the conference will let you experience various spatial sound systems in “live” conditions.
Call for papers
Your contributions are welcome, either as presentations, posters, or workshops. Submissions will undergo a review process, and accepted contributions will be published in the conference proceedings.
The conference language is English.
We are planning structured sessions on the following topics:
The submission site is open now. Contributions can be submitted here.
Closing date is July 31st, 2011.
Tags: higher order Ambisonics, International Conference on Spatial Audio, multichannel stereo, wave field synthesis
Our and most of the other talks given at the International Conference on Acoustics, Speech and Signal Processing (ICASSP) 2011 in Prague have been recorded, processed and uploaded to this portal. In particular you can find our talks on
We are not responsible for the annotation :-)
Tags: head-relatet impulse responses, local sound field synthesis, range extrapolation, wave field synthesis
Recent Comments