Illusonic goes all the way from idea – to proof of concept – to efficient C implementation – to efficient fixed point implementation – to efficient DSP native implementation. This vertical research & development approach enables uncompromised and highly computationally and memory efficient solutions.

Illusonic's competence in audio and acoustics is reflected by more than 60 scientific publications and more than 40 patent filings by its employees:

 Publications: Books/Reports

J. Breebaart and C. Faller, “Spatial Audio Processing: MPEG Surround and Other Applications,” Wiley & Sons, 2008.

C. Faller, “Spatial Audio Coding and MPEG Surround,” in “Mobile Multimedia Broadcasting Multi-Standards,” edited by Fa-Long Luo, Springer, 2008.

C. Faller, “Signal Processing for Audio and Acoustics,” Ecole Polytechnique Fédérale de Lausanne (EPFL), 2006-2008. (200 page course book).

C. Faller, “Parametric Coding of Spatial Audio,” Ph.D. Thesis No. 3062, Ecole Polytechnique Fédérale de Lausanne (EPFL), 2004.

C. Faller, “Transform Coding with Improved Quality for Speech and Other Quasi-Stationary Signals,” Diploma Thesis in Electrical Engineering, Eidgenössische Technische Hochschule Zürich (ETHZ), 1999.

 Publications: Scientific Papers (by topic)

Acoustic Echo and Noise Control

F. Küch, M. Kallinger, M. Schmidt, C. Faller, and A. Favrot, “Acoustic Echo Suppression Based on Separation of Stationary and Non-Stationary Echo Components,” in Proc. Int. Works. on Acoust. Echo and Noise Contrl., Sept. 2008.

A. Favrot, C. Faller, M. Kallinger, F. Küch, and M. Schmidt, “Acoustic Echo Control Based on Temporal Fluctuations of Short-Time Spectra,” in Proc. Int. Works. on Acoust. Echo and Noise Contrl., Sept. 2008.

A. Favrot and C. Faller, “Perceptually Motivated Gain Filter Smoothing for Noise Suppression,” in Preprint 123th Conv. Aud. Eng. Soc., Oct. 2007.

C. Faller, C. Gänsler, and M. Vetterli, “Two Stage Estimation for the Echo Paths in Stereophonic Acoustic Echo Cancellation,” in Proc. IWAENC, September 2006.

C. Faller and C. Tournery, “Stereo Acoustic Echo Control Using a Simplified Echo Path Model,” in Proc. IWAENC, September 2006.

C. Faller and C. Tournery, “Robust Acoustic Echo Control Using a Simple Echo Path Model,” in Proc. ICASSP, May 2006.

C. Faller and C. Tournery, “Estimating the Delay and Coloration Effect of the Acoustic Echo Path for Low Complexity Echo Suppression,” in Proc. Intl. Works. on Acoust. Echo and Noise Control (IWAENC), Sept. 2005.

C. Faller and J. Chen, “Suppressing acoustic echo in a sampled envelope space,” IEEE Trans. on Speech and Audio Proc., vol. 13, no. 5, Sept. 2005.

F. Wallin and C. Faller, “Perceptual quality of hybrid echo canceler/suppressor,” in Proc. ICASSP, May 2004.

C. Faller, “Perceptually motivated low complexity acoustic echo control,”
in Preprint 114th Conv. Aud. Eng. Soc., Mar. 2003.

Acoustic Signal Processing

T. Ajdler, C. Faller, L. Sbaiz, and M. Vetterli, “Sound Field Analysis along a Circle and Its Applications to HRTF Interpolation,” J. of the Audio Engineering Society, vol. 56, no. 3, Mar. 2008.

T. Ajdler, C. Faller, L. Sbaiz, and M. Vetterli, “HRTF interpolation considering wave propagation,” in Preprint 118th Conv. Aud. Eng. Soc., May. 2005.

C. Faller and M. Erne, “Modifying Attributes of Instruments in Stereo Recordings Using Acoustic Information Obtained with Spot Recordings,”
in Preprint 118th Conv. Aud. Eng. Soc., May. 2005.

Microphone Signal Processing

C. Faller and M. Kolundzija, “Design and Limitations of Non-Coincidence Correction Filters for Soundfield Microphones,” in Preprint 126th Conv. Aud. Eng. Soc., May 2009.

M. Kolundzija, C. Faller, and M. Vetterli, “Spatio-Temporal Gradient Analysis of Differential Microphone Arrays,” in Preprint 126th Conv. Aud. Eng. Soc., May 2009.

C. Faller, “Modifying the Responses of Stereo Microphones by Post-Processing,” J. of the Audio Engineering Society, vol. 56, no. 10, Oct. 2008.

C. Faller, “Microphone Front-Ends for Spatial Audio Coders,” in Preprint 125th Conv. Aud. Eng. Soc., Oct. 2008.

C. Faller, “Obtaining a Hightly Directive Channel from Coincident Stereo Microphone Signals,” in Preprint 124th Conv. Aud. Eng. Soc., May 2008.

C. Faller, “A Hightly Directive 2-Capsule Based Microphone System,”
in Preprint 123th Conv. Aud. Eng. Soc., Oct. 2007.

M. Schellstede and C. Faller, “Recording of Acoustical Concerts Using a Soundfield Microphone,” in Preprint 122th Conv. Aud. Eng. Soc., May 2007.

Perceptual Audio Coding

C. Faller, R. Haimi-Cohen, P. Kroon, and R. Rothweiler, “Perceptually based joint program coding,” in Preprint 113th Conv. Aud. Eng. Soc., October 2002.

C. Faller, B.-H. Juang, P. Kroon, H.-L. Lou, S. Ramprashad, and
C.-E. W. Sundberg, “Technical advances in digital audio radio broadcasting,” Proceedings of the IEEE, vol. 90, no. 8, Aug. 2002.

J. N. Laneman, C.-E. W. Sundberg, and C. Faller, “Huffman code based error screening and channel code optimization for error concealment in perceptual audio coding (PAC) algorithms,” IEEE Trans. on Broadcasting, vol. 48, no. 3, Sept. 2002.

C. Faller, “Audio coding using perceptually controlled bitstream buffering,”
in Preprint 111th Conv. Aud. Eng. Soc., Sept 2001.

B. Edler, C. Faller, and G. Schuller, “Perceptual audio coding using a time-varying linear pre- and post-filter,” in Preprint 109th Conv. Aud. Eng. Soc., Sept. 2000.

M. Erne, G. Moschytz, and C. Faller, “Best wavelet-packet bases for audio coding using perceptual and rate-distortion criteria,” in Proc. ICASSP, vol. 2, Mar. 1999.

Psychoacoustics and Perception

J. Merimaa and C. Faller, “Laterialization of Incoherent Narrow-Band Noise Bursts,” in Proc. DAGA, Mar. 2007.

F. Menzer and C. Faller, “Reduced Localizability in Sequences of Narrowband Noise Bursts,” in Proc. DAGA, Mar. 2007.

S. Winkler and C. Faller, “Perceived Audiovisual Quality of Low-Bitrate Multimedia Content,” IEEE Trans. Multimedia, vol. 8, no. 8, Oct. 2006.

C. Faller, “Binaural Cue Selection for Source Localization: Motivation and Experiments,” in Proc. DAGA, Mar. 2006 (invited).

S. Winkler and C. Faller, “Maximizing Audiovisual Quality at Low Bitrates,” in Proc. Intl. Workshop on Video Proc. and Quality Metrics for Consumer Electronics, Scottsdale, Arizona, USA, Jan. 2005 (invited).

S. Winkler and C. Faller, “Audiovisual Quality Evaluation of Low-Bitrate Video,” in Proc. IS&T/SPIE International Symposium Electronic Imaging, San Jose, CA, USA, vol. 5666, Jan. 2005.

C. Faller and J. Merimaa, “Source localization in complex listening situations: Selection of binaural cues based on interaural coherence,”
J. Acoust. Soc. Am., vol. 116, no. 5, Nov. 2004.

Spatial Audio

F. Menzer and C. Faller, “Binaural Reverberation Using a Modified Jot Reverberator with Frequency-Dependent Interaural Coherence Matching,” in Preprint 126th Conv. Aud. Eng. Soc., May 2009.

M. Kolundzija, C. Faller, and M. Vetterli, “Sound Field Reconstruction: An Improved Approach For Wave Field Synthesis,” in Preprint 126th Conv. Aud. Eng. Soc., May 2009.

C. Faller, “Multi-Loudspeaker Playback of Stereo Signals,” J. of the Audio Engineering Society, vol. 54, no. 11, Nov. 2006.

A. Favrot, M. Erne, and C. Faller, “Improved Cocktail Party Processing,”
in Proc. Digital Audio Effects (DAFx), Oct. 2006.

C. Faller, “Pseudostereophony Revisited,” in Preprint 118th Conv. Aud. Eng. Soc., May. 2005.

A. Härmä and C. Faller, “Spatial decomposition of time-frequency regions: Subbands or sinusoids,” in Preprint 116th Conv. Aud. Eng. Soc., May 2004.

V. Pulkki and C. Faller, “The directional effect of crosstalk in multi-channel sound reproduction,” in Proc. 18th Int. Congr. on Acoust. ICA, April 2004.

Spatial Audio Coding

J. Herre, K. Kjörling, J. Breebaart, C. Faller, S. Disch, H. Purnhagen,
J. Koppens, J. Hilpert, J. Röd´en, W. Oomen, K. Linzmeier, and K. S. Chong, “MPEG Surround - The ISO/MPEG Standard for Effcient and Compatible Multi-Channel Audio Coding,” J. of the Audio Engineering Society, vol. 56, no. 11, Nov. 2008.

J. Herre, K. Kjörling, J. Breebaart, C. Faller, S. Disch, H. Purnhagen,
J. Koppens, J. Hilpert, J. Röd´en, W. Oomen, K. Linzmeier, and K. S. Chong, “MPEG Surround - The ISO/MPEG Standard for Effcient and Compatible Multi-Channel Audio Coding,” in Preprint 122th Conv. Aud. Eng. Soc., May 2007.

C. Tournery and C. Faller, “Improved Time Delay Analysis/Synthesis for Parametric Stereo Audio Coding,” in Preprint 120th Conv. Aud. Eng. Soc., May 2006.

V. Pulkki and C. Faller, “Directional Audio Coding: Filterbank and STFT-based Design,” in Preprint 120th Conv. Aud. Eng. Soc., May 2006.

C. Faller, “Parametric Joint-Coding of Audio Sources,” in Preprint 120th Conv. Aud. Eng. Soc., May 2006.

C. Faller, “Parametric multi-channel audio coding: Synthesis of coherence cues,” IEEE Trans. on Speech and Audio Proc., vol. 14, no. 1, Jan. 2006.

J. Breebaart, J. Herre, C. Faller, J. Röden, F. Myburg, S. Disch, H. Purnhagen, G. Hotho, M. Neusinger, K. Kjörling and W. Oomen, “MPEG Spatial Audio Coding / MPEG Surround: Overview and Current Status,”
in Preprint 119th Conv. Aud. Eng. Soc., Oct. 2005.

J. Herre, H. Purnhagen, J. Breebaart, C. Faller, S. Disch, K. Kjörling, E. Schuijers, J. Hilpert, and F. Myburg, “The Reference Model Architecture for MPEG Spatial Audio Coding,” in Preprint 118th Conv. Aud. Eng. Soc., May. 2005.

J. Herre, P. Kroon, C. Faller, and S. Geyersberger, “Spatial Audio Coding: An enabling technology for bitrate-effcient and compatible multichannel audio broadcasting,” Society of motion picture and television engineers (SMPTE) Journal, 2005.

J. Herre, C. Faller, S. Disch, C. Ertel, J. Hilpert, A. Hoelzer, K. Linzmeier, C. Spenger, and P. Kroon, “Spatial Audio Coding: Next-generation effcient and compatible coding of multi-channel audio,” in Preprint 117th Conv. Aud. Eng. Soc., Oct. 2004.

C. Faller, “Parametric coding of spatial audio,” in Proc. Digital Audio Effects (DAFx), Oct. 2004 (invited).

C. Faller, “Coding of Spatial Audio Compatible with Different Playback Formats,” in Preprint 117th Conv. Aud. Eng. Soc., Oct. 2004.

J. Herre, P. Kroon, C. Faller, and S. Geyersberger, “Spatial audio coding - an enabling technology for bitrate-effcient and compatible multichannel audio broadcasting,” in Proc. IBC, Amsterdam, Sept. 2004.

J. Herre, C. Faller, C. Ertel, J. Hilpert, A. Hoelzer, and C. Spenger, “MP3 Surround: Efficient and compatible coding of multi-channel audio,”
in Preprint 116th Conv. Aud. Eng. Soc., May 2004.

F. Baumgarte, C. Faller and P. Kroon, “Audio Coder Enhancement using Scalable Binaural Cue Coding with Equalized Mixing,” in Preprint 116th Conv. Aud. Eng. Soc., May 2004.

F. Baumgarte and C. Faller, “Binaural Cue Coding - Part I: Psychoacoustic fundamentals and design principles,” IEEE Trans. on Speech and Audio Proc., vol. 11, no. 6, Nov. 2003.

C. Faller and F. Baumgarte, “Binaural Cue Coding - Part II: Schemes and applications,” IEEE Trans. on Speech and Audio Proc., vol. 11, no. 6, Nov. 2003.

C. Faller, “Binaural Cue Coding: Rendering of sources mixed into a mono signal,” in Proc. DAGA 2003, Aachen, Germany, Mar. 2003 (invited).

C. Faller and F. Baumgarte, “Binaural Cue Coding applied to audio compression with flexible rendering,” in Preprint 113th Conv. Aud. Eng. Soc., Oct. 2002.

F. Baumgarte and C. Faller, “Design and evaluation of Binaural Cue Coding schemes,” in Preprint 113th Conv. Aud. Eng. Soc., Oct. 2002.

F. Baumgarte and C. Faller, “Why Binaural Cue Coding is better than Intensity Stereo Coding,” in Preprint 112th Conv. Aud. Eng. Soc., May 2002.

C. Faller and F. Baumgarte, “Binaural Cue Coding applied to stereo and multi-channel audio compression,” in Preprint 112th Conv. Aud. Eng. Soc., May 2002.

F. Baumgarte and C. Faller, “Estimation of auditory spatial cues for Binaural Cue Coding (BCC),” in Proc. ICASSP, vol. 2, May 2002.

C. Faller and F. Baumgarte, “Binaural Cue Coding: A novel and effcient representation of spatial audio,” in Proc. ICASSP, vol. 2., May 2002

C. Faller and F. Baumgarte, “Effcient representation of spatial audio using perceptual parametrization,” in Proc. IEEE Workshop on Appl. of Sig. Proc. to Audio and Acoust., Oct. 2001. Scientific Papers: Spatial Audio Processing:

C. Faller, “Matrix Surround Revisited,” in Proc. AES 30th Int. Conf.,
Mar. 2007.