Publications de Christof Faller

Social rules govern vocal competition in the barn owl

To resolve the share of limited resources, animals often compete through exchange of signals about their relative motivation to compete. When two competitors are similarly motivated, the resolution of conflicts may be achieved in the course of an interacti ...

Elsevier2015

Echo thresholds for reflections from acoustically diffusive architectural surfaces

Christof Faller, Andreas Walther

When sound reflects from an irregular architectural surface, it spreads spatially and temporally. Extensive research has been devoted to prediction and measurement of diffusion, but less has focused on its perceptual effects. This paper examines the effect ...

Acoustical Society of America2013

Perceptual Coding of High-Quality Digital Audio

Christof Faller, Karlheinz Brandenburg

This paper introduces high-quality audio coding using psychoacoustic models. This technology is now abundant, with gadgets named after a standard (mp3 players) and the ability to play high-quality audio from literally billions of devices. The usual paradig ...

Ieee-Inst Electrical Electronics Engineers Inc2013

Interaural correlation discrimination from diffuse field reference correlations

Christof Faller, Andreas Walther

Just noticeable differences in interaural correlation (rho-jnds) from diffuse sound field reference correlations are obtained. In a three-interval, three-alternative forced-choice procedure, rho-jnds are measured for positive and negative deviations from n ...

Acoustical Soc Amer Amer Inst Physics2013

Big brother is watching you: eavesdropping to resolve family conflicts

Christof Faller

Adult animals can eavesdrop on behavioral interactions between potential opponents to assess their competitive ability and motivation to contest resources without interacting directly with them. Surprisingly, eavesdropping is not yet considered as an impor ...

Oxford University Press2013

Multi-channel low-frequency room equalization using perceptually motivated constrained optimization

Martin Vetterli, Christof Faller, Mihailo Kolundzija

We consider the problem of multiple-loudspeaker low-frequency room equalization for a wide listening area, where the equalized loudspeaker is helped using the remaining ones. Using a spatial discretization of the listening area, we formulate the problem as ...

Ieee2012

Obtaining Binaural Room Impulse Responses from B-Format Impulse Responses Using Frequency-Dependent Coherence Matching

Fritz Menzer, Christof Faller, Hervé Lissek

Measuring binaural room impulse responses (BRIRs) for different rooms and different persons is a costly and time-consuming task. In this paper, we propose a method that allows to compute BRIRs from a B-format room impulse response (B-format RIR) and a set ...

Institute of Electrical and Electronics Engineers2011

Direct-Ambient Decomposition and Upmix of Surround Signals

Christof Faller, Andreas Walther

Various direct-ambient signal decompositions, applicable to two-channel stereophonic signals, have been proposed previously. Strategies to enhance these decompositions for multi-channel surround audio signals are not obvious. A method is proposed, which es ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

Spatiotemporal Gradient Analysis of Differential Microphone Arrays

Martin Vetterli, Christof Faller, Mihailo Kolundzija

The literature on gradient and differential microphone arrays makes a distinction between the two types, and nevertheless shows how both types can be used to obtain the same directional responses. A more theoretically sound rationale for using delays in di ...

2011

Reproducing Sound Fields Using MIMO Acoustic Channel Inversion

Martin Vetterli, Christof Faller, Mihailo Kolundzija

Sound fields are essentially band-limited phenomena, both temporally and spatially. This implies that a spatially sampled sound field respecting the Nyquist criterion is effectively equivalent to its continuous original. We describe Sound Field Reconstruct ...

2011

Method and Device for Removing Echo in an Audio Signal

Christof Faller

Acoustic echo control and noise suppression is an important part of any "handsfree" telecommunication system, such as telephony or audio or video conferencing systems. Bandwidth and computational complexity constraints have prevented that stereo or multi-c ...

2010

Baffled Circular Loudspeaker Array With Broadband High Directivity

Martin Vetterli, Christof Faller, Mihailo Kolundzija

Super-directional loudspeaker arrays can be used to achieve high directivity in a limited low-frequency range. As opposed to microphone arrays, the distance between the loudspeakers has to be relatively large, resulting in aliasing starting at relatively l ...

2010

Feeling in control of your footsteps: Conscious gait monitoring and the auditory consequences of footsteps

Martin Vetterli, Fritz Menzer, Christof Faller, Olaf Blanke, Pär Halje

A fundamental aspect of the “I” of conscious experience is that the self is experienced as a single coherent representation of the entire, spatially situated body. The purpose of the present study was to investigate agency for the entire body. We provided ...

2010

Method And Device For Removing Echo In A Multi-Channel Audio Signal

Christof Faller

Acoustic echo control and noise suppression is an important part of any "handsfree" telecommunication system, such as telephony or audio or video conferencing systems. Bandwidth and computational complexity constraints have prevented that stereo or multi-c ...

2008

Sound Field Analysis Along a Circle and its Application to HRTF Interpolation

Martin Vetterli, Luciano Sbaiz, Christof Faller, Thibaut Ajdler

The sampling and interpolation of a sound field in two and three dimensions along a circle is discussed. The Fourier domain representation of the sound field is used, and an angular sampling theorem is developed for the sampling of the sound field along a ...

2008

Method to generate multi-channel audio signals from stereo signals

Christof Faller

A perceptually motivated spatial decomposition for two-channel stereo audio signals, capturing the information about the virtual sound stage, is proposed. The spatial decomposition allows to re-synthesize audio signals for playback over other sound systems ...

2007

Parametric joint-coding of audio sources

Christof Faller

The following coding scenario is addressed: A number of audio source signals need to be transmitted or stored for the purpose of mixing wave field synthesis, multi channel surround, or stereo signals after decoding the source signals. The proposed techniqu ...

2007

Christof Faller

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Social rules govern vocal competition in the barn owl

Echo thresholds for reflections from acoustically diffusive architectural surfaces

Perceptual Coding of High-Quality Digital Audio

Interaural correlation discrimination from diffuse field reference correlations

Big brother is watching you: eavesdropping to resolve family conflicts

Multi-channel low-frequency room equalization using perceptually motivated constrained optimization

Obtaining Binaural Room Impulse Responses from B-Format Impulse Responses Using Frequency-Dependent Coherence Matching

Direct-Ambient Decomposition and Upmix of Surround Signals

Spatiotemporal Gradient Analysis of Differential Microphone Arrays

Reproducing Sound Fields Using MIMO Acoustic Channel Inversion

Method and Device for Removing Echo in an Audio Signal

Baffled Circular Loudspeaker Array With Broadband High Directivity

Feeling in control of your footsteps: Conscious gait monitoring and the auditory consequences of footsteps

Method And Device For Removing Echo In A Multi-Channel Audio Signal

Sound Field Analysis Along a Circle and its Application to HRTF Interpolation

Method to generate multi-channel audio signals from stereo signals

Parametric joint-coding of audio sources

Recording of Acoustical Concerts Using a Soundfield Microphone

Matrix Surround Revisited

MPEG Surround - The ISO/MPEG Standard for Efficient and Compatible Multi-Channel Audio Coding