Lange Nacht der Wissenschaften / Long Night of the Sciences

Posted on 2. June 2010 by Sascha Spors

Deutsche Telekom Laboratories and especially the audio group of the Quality and Usability Lab will participate in the Long Night of the Sciences in Berlin. We show a combination of a very nice multitouch interface in conjunction with spatial audio reproduction. Visit us next Saturday in the TU Hochhaus at Ernst-Reuter-Platz 7.

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New paper published

Posted on 26. May 2010 by Sascha Spors

This May we have presented a number of papers at the following conferences

You can find all the references and download some of the papers/presentations at my homepage or here in the BLOG.

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Audio Examples for the Paper “Perceptual Evaluation of Focused Sources in Wave Field Synthesis”, 128th AES Conv., London.

Posted on 24. May 2010 by matthias.geier

This post contains supplementary audio examples for the paper:

Geier, Wierstorf, Ahrens, Wechsung, Raake, Spors: Perceptual Evaluation of Focused Sources in Wave Field Synthesis. 128th AES Convention, London, May 2010.

Please use headphones to appreciate the spatial information!

The provided files are named using the following scheme:

<array length>_<radius>_<angle>_<input sound>.wav

Array length is 4 meters or 10 meters; the radius (= distance from the focused source) is 1 and 4 meters, respectively. The focused source is always located one meter in front of the loudspeaker array. The angle is 0, 30 or 60 degrees. The input sound is either castanets or female speech.

The geometry of the experiment is shown in the following figure.

Sketch of the geometry used in the experiment

In addition, there are also 2 reference stimuli, ref_phi0_speech.wav and ref_phi0_castanets.wav using plain HRTFs for the frontal direction.

You can download a ZIP-file with all audio examples.

More detailed information can be found in the paper and in the slides.

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Audio examples for paper “Ahrens, Geier, Spors: Perceptual Assessment of Delay Accuracy and Loudspeaker Misplacement in Wave Field Synthesis. 128th AES Convention”

Posted on 23. May 2010 by Jens Ahrens

On this post you find audio examples for the experiments presented in the paper

Jens Ahrens, Matthias Geier, Sascha Spors: Perceptual assessment of delay accuracy and loudspeaker misplacement in Wave Field Synthesis. 128th Convention of the AES, London, UK, May 22-25, 2010 [ pdf ] .

NOTE THAT THESE EXAMPLES ARE INTENDED FOR HEADPHONE REPRODUCTION!!! The examples contain the signals for 0° orientation of the listener (i.e. straight forward).

Download zipped files for delay accuracy experiment.

Download zipped files for radius accuracy experiment.

Download zipped files for random radial displacement experiment.

The file names are composed of the input signal, listening position, delay accuracy, and the radius which is employed in the calculation of the driving function. If applicable also the displacement range is indicated. Parameters are explained in the paper.

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Open Source Release of the SoundScape Renderer

Posted on 21. May 2010 by Sascha Spors

We are proud to annouce the first public release of the SoundScape Renderer (SSR). The SoundScape Renderer 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 and binuaral techniques. The SSR is currently available for Linux and has been released as open source software under the GPL. Find more information of its homepage.

The current release 0.3 can be downloaded in the files section of the SSR development page.

Please use SoundScapeRenderer@telekom.de for questions, feedback and bug reports.

The SSR development team

SSR in binaural mode

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Audio examples for the paper “Die Rolle des Präzedenzeffektes bei der Wahrnehmung von räumlichen Aliasingartefakten bei der Wellenfeldsynthese”, DAGA 2010.

Posted on 21. April 2010 by Hagen Wierstorf

This post contains supplementary audio examples for the paper:

H. Wierstorf, S. Spors, A. Raake: Die Rolle des Präzedenzeffektes bei der Wahrnehmung von räumlichen Aliasingartefakten bei der Wellenfeldsynthese. DAGA 2010, Berlin.

A sketch of the used stimuli is shown in the figure below for the 6 dB condition. For further details on the stimuli you can have a look at the paper or the presentation.

Sketch of the stimuli

The download of the stimuli is splitted in four different dB conditions, the naming of each stimuli is done after is dB value and number of echos in n1 and n2: 0 dB, 3 dB, 6 dB, 10 dB

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Multitouch interface for the SSR

Posted on 12. April 2010 by Sascha Spors

In the scope of an applied project we have worked together with contentismissing on a multitouch interface for the SSR using the Stantum Multitouch Screen. You can get a glimpse of the nice interface at their BLOG.

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Audio examples for paper “Ahrens, Geier, Spors: Perceptional Comparison of Wave Field Synthesis Implemented With Integer And Fractional Delays. DAGA 2010, Berlin”

Posted on 23. March 2010 by Jens Ahrens

On this post you find audio examples for the experiment presented in the paper

Jens Ahrens, Matthias Geier, Sascha Spors: Perceptional Comparison of Wave Field Synthesis Implemented with Integer and Fractional Delays. DAGA, Berlin, Germany, March 15-18, 2010 [ pdf ] .

NOTE THAT THESE EXAMPLES ARE INTENDED FOR HEADPHONE REPRODUCTION!!! The examples contain the signals for 0° orientation of the listener (i.e. straight forward).

Download zipped files.

The file names are composed of the input signal, listening position, and delay accuracy. Parameters are explained in the paper.

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Acoustic focusing by the spectral division method

Posted on 22. March 2010 by Sascha Spors

I have extended the spectral division method (SDM) in a recent paper presented at the ISCCSP 2010 for the reproduction of focused sources. The mathematical analysis revealed some quite interesting facts about the role of evanescent contributions in this context. If one aims at modelling the field of an acoustic point source in front of a loudspeaker array including its evanescent contributions one ends up with evanescent contributions with excessive levels before the focus point. I have created two videos for my talk at the ISCCSP 2010 in order to illustrate the problem.

The first video shows the reproduction of a focused source using the SDM when including the evanescent contributions in the desired field:

The background for this effect is the repidly decaing evanescent contributions of the secondary sources. These have to be driven at excessive levels in order to produce the desired evanescent contributions at the focus point.

The second video shows the same situation when discarding the evanescent parts in the model of the desired wave field:

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DEGA Studienpreis

Posted on 22. March 2010 by Sascha Spors

Benjamin Bernschütz has won the “DEGA-Studienpreis” for his Master Thesis with the (translated) title “Wavefield analysis using spherical microphone arrays”. He has conducted his thesis at the audio group of Deutsche Telekom Laboratories in Berlin.

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