About the Author

Biography

Jens Ahrens is Associate Professor at the Division of Applied Acoustics at Chalmers University of Technology in Gothenburg, Sweden. He received a Diplom in Electrical Engineering/Sound Engineering (equivalent to an M.Sc.) from Graz University of Technology and University of Music and Dramatic Arts Graz, Austria, in 2005 and the Doctoral Degree (Dr.-Ing.) from University of Technology Berlin, Germany, in 2010. From 2006 to 2011, he was member of the Audio Technology Group at Deutsche Telekom Laboratories / TU Berlin where he worked on the topic of sound field synthesis. From 2011 to 2013 he was a Postdoctoral Researcher at Microsoft Research in Redmond, Washington, USA, after which he re-joined the Quality and Usability Lab at University of Technology Berlin. In the fall/winter terms 2015/16, he was Visiting Scholar at the Center for Computer Research in Music and Acoustics (CCRMA) at Stanford University.

Awards and Grants

  • Horizon 2020 – FET Open (Levitate)
  • DAAD Postdoc grant, DAAD travel grant
  • DFG grant AH 269/2-1
  • Literature award 2013 of the Information Technology Society (ITG at VDE) for the book “Analytic Methods of Sound Field Synthesis”
  • Doctoral degree awarded with distinction
  • Diploma degree awarded with distinction

Selected Presentations

  • J. Ahrens, S. Spors, H. Wierstorf: Sound Field Synthesis using Loudspeaker Arrays. Workshop on Binaural Factors and Compensation Schemes in Hearing Impairment, Hanse-Wissenschaftskolleg, Delmenhorst, Germany, 2015 (invited presentation)
  • J. Ahrens, J.-N. Antons, S. Moeller: From Speech Communication to Audio Communication, World Telecommunications Congress (WTC), Berlin, 2014 (invited presentation) [ Abstract ]
  • Jens Ahrens: The Psychoacoustics of Synthetic Sound Fields, Hearing Seminar, CCRMA, Stanford University, 2013 [ Abstract ]

Publications

(Jens Ahrens’s profile on Google Scholar)

Books and Book Chapters

  • R. Rabenstein, S. Spors, and J. Ahrens: Sound Field Synthesis, in R. Chellappa and S. Theodoridis (edt.): “Academic Press Library in Signal Processing: Volume 4”, 1st Edition, Academic Press (Chennai), 2013, p. 915 – 979 [ AP site ]
  • Jens Ahrens: Analytic Methods of Sound Field Synthesis, Springer-Verlag (Berlin/Heidelberg), 2012 [ Springer site ]

Theses

  • Jens Ahrens: The Single-layer Potential Approach Applied to Sound Field Synthesis Including Cases of Non-enclosing Distributions of Secondary Sources. Doctoral Dissertation, Technische Universität Berlin, 2010
  • Jens Ahrens: Voice Transformation. Diploma Thesis, IEM Graz, 2005

Articles in Journals

  • F. Winter, J. Ahrens, S. Spors: On Analytic Methods for 2.5D Local Sound Field Synthesis Using Circular Distributions of Secondary Sources, in IEEE/ACM Transactions on Audio, Speech, and Language Processing, vol. 24, no. 5, pp. 914-926, Feb. 2016, DOI: 10.1109/TASLP.2016.2531902
  • J. Ahrens, R. Rabenstein, S. Spors: Sound Field Synthesis for Audio Presentation, in Acoustics Today, vol. 10, no. 2, pp. 15-25, Spring 2014 [ pdf, animations ]
  • A. Avni, J. Ahrens, M. Geier, S. Spors, H. Wierstorf, B. Rafaely: Spatial Perception of Sound Fields Recorded by Spherical Microphone Arrays with Varying Spatial Resolution, in JASA, vol. 133, no. 5, pp. 2711-2721, May 2013, DOI: 10.1121/1.4795780
  • Jens Ahrens and Sascha Spors: A Modal Analysis of Spatial Discretization of Spherical Loudspeaker Distributions Used for Sound Field Synthesis, in IEEE Transactions on Audio, Speech, and Language Processing, vol. 20, no. 9, pp. 2564-2574, IEEE, November 2012, DOI: 10.1109/TASL.2012.2208625
  • Jens Ahrens and Sascha Spors: Wave field synthesis of a sound field described by spherical harmonics expansion coefficients, in JASA, vol. 131, no. 3, pp. 2190-2199, Acoustical Society of America, March 2012, DOI: 10.1121/1.3682036
  • Jens Ahrens and Sascha Spors: Applying the Ambisonics approach to planar and linear distributions of secondary sources and combinations thereof, in Acta Acustica utd. with Acustica, vol. 98, no. 1, pp. 28-36, January 2012, DOI: 10.3813/AAA.918489
  • Jens Ahrens and Sascha Spors: Wave field synthesis of moving virtual sound sources with complex radiation properties, in JASA, vol. 130, no. 5, pp. 2807-2816, Acoustical Society of America, November 2011, DOI: 10.1121/1.3640850
  • Jens Ahrens and Sascha Spors: Sound Field Reproduction Using Planar and Linear Arrays of Loudspeakers, in IEEE Transactions on Audio, Speech, and Language Processing, vol. 18, no. 8, IEEE, November 2010, DOI: 10.1109/TASL.2010.2041106
  • Matthias Geier, Jens Ahrens, and Sascha Spors, Object-based Audio Reproduction and the Audio Scene Description Format, in Organized Sound, vol. 15, no. 3, 2010, DOI: 10.1017/S1355771810000324
  • Jens Ahrens and Sascha Spors: An Analytical Approach to Sound Field Reproduction Using Circular and Spherical Loudspeaker Distributions, in Acta Acustica utd. with Acustica, vol. 94, no. 6, November 2008, DOI: 10.3813/AAA.918115

Conference Contributions

2017

  • J. Ahrens, P. Bartz, M. Geier, S. Spors: The Interactive SoundScape Renderer for Loudspeaker- and Headphone-Based Spatial Sound Presentation, Demo at the 23rd ACM Symposium on Virtual Reality Software and Technology, Gothenburg, Sweden, Nov. 2017
  • Jens Ahrens: Amplitude Engineering for Beamformers with Self-Bending Directivity Based on Convex Optimization, IEEE WASPAA, New Paltz, NY, 2017 (accepted)
  • J. Ahrens, C. Hohnerlein, C. Andersson: Auralization of acoustic spaces based on spherical microphone array recordings. Acoustics ’17, Boston, MA, USA, 2017 [ slides ]
  • S. Möller et al.: A Cross-University Massive Open Online Course on Communication Acoustics. Acoustics ’17, Boston, MA, USA, 2017 [ pdf ]
  • S. Möller et al.: TU9-MOOC Communication Acoustics: Erste Erfahrungen. DAGA, Kiel, Germany, 2017 [ pdf ]
  • Christoph Hohnerlein, Jens Ahrens: Spherical Microphone Array Processing in Python with the sound_field_analysis-py Toolbox. DAGA, Kiel, Germany, 2017 [ pdf ]
  • Jens Ahrens: Evaluation of the Impact of Spatial Aliasing on Perceived Spaciousness in Wave Field Synthesis. DAGA, Kiel, Germany, 2017 [ pdf ]
  • T. Hedke, J. Ahrens, J. Beyer, S. Möller: Impact of Spatial Audio Presentation on the Quality of Experience of Computer Games. DAGA, Kiel, Germany, 2017 [ pdf ]
  • Christoph Hohnerlein, Jens Ahrens: Perceptual Evaluation Of A Multiband Acoustic Crosstalk Canceler Using A Linear Loudspeaker Array. IEEE ICASSP, New Orleans, LA, USA, 2017

2016

  • Jens Ahrens and Ralf Vogelgesang: A Linear Sensor Array With Self-Bending Sensitivity. IEEE ICASSP, Shanghai, China, 2016 [ pdf ]
  • Sebastian Möller et al.: Konzeption eines MOOC der TU9 zum Thema Communication Acoustics. DAGA, Aachen, Germany, 2016 [ pdf ]
  • Jens Ahrens: On the Generation of Virtual Early Reflections in Wave Field Synthesis. DAGA, Aachen, Germany, 2016 [ pdf, audio examples ]

2015

  • Jens Ahrens and Hagen Wierstorf: Recent Advancements in Massive Multi-Channel Auralization. 170th Meeting of the Acoustical Society of America, Jacksonville, Florida, 2015
  • F. Köster, F. Schiff ner, D. Guse, J. Ahrens, J. Skowronek, S. Möller: Towards a MATLAB Toolbox for Imposing Speech Signal Impairments Following the P.TCA Schema. 139th Convention of the AES, New York, NY, 2015
  • D. Kelvasa, J. Ahrens, J.-N. Antons: The ventriloquist effect evokes changes in the early spatial processing of auditory stimuli as measured by the mismatch negativity. 7th Mismatch Negativity Conference, Leipzig, Germany, 2015 [ poster ]
  • Jens Ahrens: Perceptual Evaluation of the Diffuseness of Synthetic Late Reverberation Created by Wave Field Synthesis at Different Listening Positions. DAGA, Nürnberg, 2015 [ pdf, audio examples ]
  • Jens Ahrens and Hagen Wierstorf: Properties of Large-scale Sound Field Synthesis. 57th Conference of the AES, Hollywood, CA, USA, 2015 [ pdf ]

2014

  • P. Bilinski, J. Ahrens, M.R.P. Thomas, I.J. Tashev, J. Platt: HRTF Magnitude Synthesis via Sparse Representation of Anthropometric Features. IEEE ICASSP, Florence, Italy, 2014 [ pdf ]
  • M.R.P. Thomas, J. Ahrens, I.J. Tashev: A Method for Converting Between Circular and Spherical Harmonic Representations of Sound Fields. IEEE ICASSP, Florence, Italy, 2014 [ pdf ]
  • Jens Ahrens: Challenges in the Creation of Artificial Reverberation for Sound Field Synthesis: Early Reflections and Room Modes. EAA Joint Symposium on Auralization and Ambisonics, Berlin, Germany, 2014 [ pdf, animations ]

2013

  • J. Ahrens, M.R.P. Thomas, and I. Tashev: Gentle Acoustic Crosstalk Cancelation Using the Spectral Division Method and Ambiophonics. IEEE WASPAA, New Paltz, NY, USA, 2013 [ pdf ]
  • J. Ahrens, M.R.P. Thomas, and I. Tashev: Efficient Implementation of the Spectral Division Method for Arbitrary Virtual Sound Fields. IEEE WASPAA, New Paltz, NY, USA, 2013 [ pdf ]

2012

  • J. Ahrens, M.R.P. Thomas, and I. Tashev: HRTF Magnitude Modeling Using a Non-Regularized Least-squares Fit of Spherical Harmonics Coefficients on Incomplete Data. APSIPA, Hollywood, CA, USA, 2012 [ pdf ]
  • M.R.P. Thomas, J. Ahrens, and I. Tashev: Beamformer Design Using Measured Microphone Directivity Patterns: Robustness and Modelling Error. APSIPA, Hollywood, CA, USA, 2012 [ pdf ]
  • M.R.P. Thomas, J. Ahrens, and I. Tashev: Optimal 3D Beamforming Using Measured Microphone Directivity Patterns. IWAENC, Aachen, Germany, 2012 [ pdf ]
  • M. Cobos, S. Spors, J. Ahrens, and J.J. Lopez: On the Use of Small Microphone Arrays for Wave Field Synthesis Auralization. 45th Conference of the AES, Helsinki, Finland, 2012 [ pdf ]

2011

  • S. Spors, V. Kuscher, and J. Ahrens: Efficient Realization of Model-Based Rendering for 2.5-dimensional Near-Field Compensated Higher Order Ambisonics. IEEE WASPAA, New Paltz, NY, USA, 2011 [ pdf ]
  • S. Spors, K. Helwani, and J. Ahrens: Local sound field synthesis by virtual acoustic scattering and time-reversal. 131st Convention of the AES, NYC, NY, USA, 2011 [ pdf ]
  • Jens Ahrens and Sascha Spors: Two Physical Models for Spatially Extended Virtual Sound Sources. 131st Convention of the AES, NYC, NY, USA, 2011 [ pdf ]
  • Jens Ahrens and Sascha Spors: An Analytical Approach to Local Sound Field Synthesis Using Linear Arrays of Loudspeakers. IEEE ICASSP, Prague, Czech Republic, 2011 [ pdf ]
  • Sascha Spors and Jens Ahrens: Efficient Range Extrapolation of Head-Related Impulse Responses by Wave Field Synthesis Techniques. IEEE ICASSP, Prague, Czech Republic, 2011 [ pdf ]
  • Jens Ahrens and Sascha Spors: On the Scattering of Synthetic Sound Fields. 130th Convention of the AES, London, UK, 2011 [ pdf ]
  • S. Spors, H. Wierstorf, J. Ahrens: Interpolation and Range Extrapolation of Head-Related Transfer Functions Using Virtual Local Wave Field Synthesis. 130th Convention of the AES, London, UK, 2011 [ pdf ]
  • Sascha Spors and Jens Ahrens: Generation of far-field head-related transfer functions using sound field synthesis. DAGA, Düsseldorf, 2011 [ pdf ]
  • Jens Ahrens und Sascha Spors: Über die Streuung im synthetischen Schallfeld. DAGA, Düsseldorf, 2011 [ pdf ]

2010

  • Jens Ahrens and Sascha Spors: On the Anti-Aliasing Loudspeaker for Sound Field Synthesis Employing Linear and Circular Distributions of Secondary Sources. 129th Convention of the AES, San Francisco, CA, USA, Nov. 4-7, 2010 [ pdf ]
  • J. Ahrens, H. Wierstorf, and S. Spors: Comparison of Higher Order Ambisonics And Wave Field Synthesis With Respect to Spatial Discretization Artifacts in Time Domain. 40th Conference of the AES, Tokyo, Japan, Oct. 8-10, 2010 [ pdf ]
  • Sascha Spors and Jens Ahrens: Local Sound Field Synthesis by Virtual Secondary Sources. 40th Conference of the AES, Tokyo, Japan, Oct. 8-10, 2010 [ pdf ]
  • A. Raake, C. Schlegel, M. Geier, J. Ahrens: Listening and Conversational Quality of Spatial Audio Conferencing. 40th Conference of the AES, Tokyo, Japan, Oct. 8-10, 2010 [ pdf ]
  • M. Geier, H. Wierstorf, J. Ahrens, I. Wechsung, A. Raake, S. Spors: Perceptual Evaluation of Focused Sources in Wave Field Synthesis. 128th Convention of the AES, London, UK, May 22-25, 2010 [ pdf ]
  • Sascha Spors, Jens Ahrens: Analysis and improvement of pre-equalization in 2.5-dimensional wave field synthesis. 128th Convention of the AES, London, UK, May 22-25, 2010 [ pdf ]
  • 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 ]
  • Jens Ahrens, Sascha Spors: Applying the Ambisonics approach on planar and linear arrays of loudspeakers. 2nd Int. Symposium on Ambisonics and Spherical Acoustics, Paris, France, May 6-7, 2010 [ pdf ]
  • J. Ahrens, M. Geier, S. Spors: Perceptional Comparison of Wave Field Synthesis Implemented with Integer and Fractional Delays. DAGA, Berlin, Germany, March 15-18, 2010 [ pdf ]
  • A. Raake, C. Schlegel, M. Geier, J. Ahrens: Hör- und Konversationstests zur Untersuchung der Vorteile räumlicher Audiokonferenzen. DAGA, Berlin, Germany, March 15-18, 2010 [ pdf ]
  • Jens Ahrens and Sascha Spors: An Analytical Approach To 2.5D Sound Field Reproduction Employing Linear Distributions Of Non-Omnidirectional Loudspeakers. IEEE ICASSP, Dallas, Texas, March 14-19, 2010 [ pdf ]
  • Jens Ahrens and Sascha Spors: An Analytical Approach to 3D Sound Field Reproduction Employing Spherical Distributions of Non-Omnidirectional Loudspeakers. 4th IEEE ISCCSP, Limassol, Cyprus, March 3-5, 2010 [ pdf ]
  • Sascha Spors and Jens Ahrens: Reproduction of Focused Sources by the Spectral Division Method. 4th IEEE ISCCSP, Limassol, Cyprus, March 3-5, 2010 [ pdf ]

2009

  • Jens Ahrens and Sascha Spors: Artifacts in the Sound Field of a Moving Source Reconstructed From a Microphone Array Recording. IEEE WASPAA, New Paltz, NY, Oct. 18-21, 2009 [ pdf ]
  • S. Spors, H. Wierstorf, M. Geier, and J. Ahrens: Physical and perceptual properties of focused sources in wave field synthesis. 127th Convention of the AES, New York, NY, Oct. 9–12, 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: On the Secondary Source Type Mismatch in Wave Field Synthesis Employing Circular Distributions of Loudspeakers. 127th Convention of the AES, New York, NY, Oct. 9–12, 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: An Analytical Approach to 2.5D Sound Field Reproduction Employing Circular Distributions of Non-Omnidirectional Loudspeakers. 17th European Signal Processing Conference, Glasgow, UK, August 24-28, 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: Spatial Encoding and Decoding of Focused Virtual Sound Sources. Ambisonics Symposium, Graz, Austria, June 25-27, 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: Alterations of the Temporal Spectrum in High-Resolution Sound Field Reproduction of Different Spatial Bandwidths. 126th Convention of the AES, Munich, Germany, May 7–10, 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: Sound Field Reproduction Employing Non-Omnidirectional Loudspeakers. 126th Convention of the AES, Munich, Germany, May 7–10, 2009 [ pdf ]
  • Sascha Spors and Jens Ahrens: Spatial Sampling Artifacts of Wave Field Synthesis for the Reproduction of Virtual Point Sources. 126th Convention of the AES, Munich, Germany, May 7–10, 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: An Analytical Approach to Sound Field Reproduction with a Movable Sweet Spot Using Circular Distributions of Loudspeakers. IEEE ICASSP, Taipei, Taiwan, April 19.-24., 2009 [ pdf ]
  • Jens Ahrens and Sascha Spors: Timbral Coloration in High-Resolution Sound Field Reproduction Due to Spatial Bandwidth Limitation. Intern. Conf. on Acoustics NAG/DAGA, Rotterdam, The Netherlands, March 23.-26., 2009 [ pdf ]
  • Matthias Geier, Jens Ahrens, Sascha Spors: Binaural Monitoring of Massive Multichannel Sound Reproduction Systems Using Model Based Rendering. Intern. Conf. on Acoustics NAG/DAGA, Rotterdam, The Netherlands, March 23.-26., 2009 [ pdf ]
  • Sascha Spors and Jens Ahrens: Spatial Sampling Artifacts of Focused Sources in Wave-Field Synthesis. Intern. Conf. on Acoustics NAG/DAGA, Rotterdam, The Netherlands, March 23.-26., 2009 [ pdf ]

2008

  •  Jens Ahrens and Sascha Spors: Reproduction of Virtual Sound Sources Moving at Supersonic Speeds in Wave Field Synthesis. 125th Convention of the AES, San Francisco, CA, Oct. 2–5, 2008 [ pdf, animations ]
  • Sascha Spors and Jens Ahrens: A Comparison of Wave Field Synthesis and Higher-Order Ambisonics with Respect to Physical Properties and Spatial Sampling. 125th Convention of the AES, San Francisco, CA, Oct. 2–5, 2008 [ pdf ]
  • T. Schaefers, M. Rohs, S. Spors, A. Raake, and J. Ahrens. Designing low-dimensional interaction for mobile navigation in 3D audio spaces. In 34th International AES Conference, Jeju Island, Korea, Aug. 28-30, 2008 [ pdf ]
  • Jens Ahrens and Sascha Spors: Notes on the reproduction of moving virtual sound sources. Acoustics’08, Paris, France, June 29- July 4, 2008 (abstract only)
  • Sascha Spors and Jens Ahrens: Towards a theory for arbitrarily shaped sound field reproduction systems. Acoustics’08, Paris, France, June 29- July 4, 2008 (abstract only)
  • Katharina Bredies, Nick A. Mann, Jens Ahrens, Matthias Geier, Sascha Spors, Michael Nischt: The Multi-Touch SoundScape Renderer. Advanced Visual Interfaces, Napoli, Italy, May 28-30, 2008 [ pdf ]
  • Jens Ahrens and Sascha Spors: Focusing of Virtual Sound Sources in Higher Order Ambisonics. 124th Convention of the AES, Amsterdam, The Netherlands, May 17–20, 2008 [ pdf ]
  • Jens Ahrens and Sascha Spors: Reproduction of Moving Virtual Sound Sources with Special Attention to the Doppler Effect. 124th Convention of the AES, Amsterdam, The Netherlands, May 17–20, 2008 [ pdf ]
  • Sascha Spors, Rudolf Rabenstein, and Jens Ahrens: The theory of wave field synthesis revisited. 124th Convention of the AES, Amsterdam, The Netherlands, May 17–20, 2008 [ pdf ]
  • Matthias Geier, Sascha Spors, and Jens Ahrens: The SoundScape Renderer: A Unified Spatial Audio Reproduction Framework for Arbitrary Rendering Methods. 124th Convention of the AES, Amsterdam, The Netherlands, May 17–20, 2008 [ pdf ]
  • Jens Ahrens and Sascha Spors: Notes on Rendering Focused Directional Virtual Sound Sources in Wave Field Synthesis. 34. Jahrestagung der Deutschen Gesellschaft für Akustik, Dresden, 10. – 13. März, 2008 [ pdf ]
  • Matthias Geier, Jens Ahrens und Sascha Spors: ASDF: Ein XML Format zur Beschreibung von virtuellen 3D-Audioszenen. 34. Jahrestagung der Deutschen Gesellschaft für Akustik, Dresden, 10. – 13. März, 2008 [ pdf ]
  • Jens Ahrens and Sascha Spors: Analytical driving functions for higher order Ambisonics. IEEE Int. Conference on Acoustics, Speech, and Signal Processing (ICASSP), March 30 – April 4, Las Vegas, Nevada, 2008 [ pdf ]
  • Jens Ahrens and Sascha Spors: Reproduction of a plane-wave sound field using planar and linear arrays of loudspeakers. IEEE Int. Symposium on Communications Control and Signal Processing (ISCCSP), March 12–14, Malta, 2008 [ pdf ]

2007

  • Jens Ahrens and Sascha Spors: Implementation of Directional Sources in Wave Field Synthesis, 2007 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, October 21-24, 2007, New Paltz, NY [ pdf ]
  • Jens Ahrens and Sascha Spors: Rendering of virtual sound sources with arbitrary directivity in higher order Ambisonics. 123rd Convention of the Audio Engineering Society (AES), 2007 October 5–8 New York, NY [ pdf ]
  • Matthias Geier, Jens Ahrens, André Möhl, Sascha Spors, Jonas Loh, Katharina Bredies: The Soundscape renderer: A versatile software framework for spatial audio reproduction. Proceedings of 1st DEGA Symposium on Wave Field Synthesis, Ilmenau, Germany, Sept. 2007 [ pdf ]
  • Sascha Spors and Jens Ahrens: Comparison of Higher-Order Ambisonics and Wave Field Synthesis with Respect to Spatial Aliasing Artifacts. 19th International Congress on Acoustics (ICA), Madrid, 2-7 September 2007 [ pdf ]
  • Alexander Raake, Sascha Spors, Jens Ahrens, Jitendra Ajmera: Concept and Evaluation of a Downward-Compatible System for Spatial Teleconferencing using Automatic Speaker Clustering. ICSLP Interspeech, Antwerp, Belgium, August 27-31 2007 [ pdf ]
  • Jens Ahrens, Alexander Raake, Sascha Spors, Jitendra Ajmera: Ein rückwärtskompatibles räumliches Telefonkonferenzsystem mit automatischer Sprechergruppierung. 33. Jahrestagung der Deutschen Gesellschaft für Akustik, Stuttgart, März 2007 [ pdf ]
  • Sascha Spors and Jens Ahrens: Analysis of Near-Field Effects of Wave Field Synthesis using Linear Loudspeaker Arrays. AES 30th International Conference, Saariselkä, Finland, 2007 March 15–17 [ pdf ]

Sound Engineering

  • Steve Reich: Six Marimbas (1984). Adaptation for wave field synthesis by Jens Ahrens, 2008. Performances:
    – 124th Convention of the AES, Amsterdam, The Netherlands, May 2008
    – Lange Nacht der Wissenschaften, Berlin, Germany, June 2008