CIRMMT workshop on spatial audio

The first CIRMMT workshop on spatial audio will take place on Monday, 23 April 2007 at the Université de Sherbrooke. A bus will leave the Schulich School of Music of McGill University for Sherbrooke at 7:15am that morning. This workshop involves CIRMMT research axes 1, 4, 5 and 6.

Agenda/Ordre du jour

  • 7:15 Departure for Sherbrooke
  • 9:30 Coffee
  • 10:00 Introduction: McAdams, Berry
  • 10:10 Presentation of GAUS: Berry

 Brief individual presentations

  • 10:20 1. Alain Berry
  • 10:30 2. Catherine Guastavino
  • 10:40 3. Bill Martens
  • 10:50 4. Robert Zatorre
  • 11:00 5. Jeremy Cooperstock
  • 11:10 6. Zack Settel
  • 11:20 7. Stephen McAdams
  • 11:30 8. Sean Ferguson
  • 11:40 9. Robert Normandeau
  • 11:50 10. Jean Piché
  • 12:00 Synthesis and discussion
  • 12:30 Lunch
  • 13:30 Tour of GAUS
  • 14:00 Demonstration (Berry, Gauthier)
  • 14:30 Debate I
  • 15:15 Debate II
  • 16:00 Coffee break
  • 16:15 Collaborative projects
  • 17:00 ICAD Workshop
  • 17:30 Departure for Montreal

 

Participants

CIRMMT Researchers
Berry, Alain (UdeS)
Cooperstock, Jeremy (McGill)
Ferguson, Sean (McGill)
Guastavino, Catherine (McGill)
Martens, Bill (McGill)
McAdams, Stephen (McGill)
Normandeau, Robert (UdeM)
Piché, Jean (UdeM)
Traube, Caroline (UdeM)
Zatorre, Robert (McGill)

Other researchers/Autres chercheurs
Lapointe, Robby (Bombardier Aerospace)
Chagnon, Philippe (CAE Electronique)
Settel, Zack (SAT)
Yann Pasco (UdeS)

Post-docs, grad students
Bélanger, Olivier (UdeM)a
Benson, David (McGill)
Gaskell, Eric (McGill)
Gauthier, Philippe-Aubert (UdeS)
Lécaudé, Nathanaël (UdeM)
Marentakis, Georgios (McGill)
Marier, Martin (UdeM)
Peters, Nils (McGill)
Visell, Yon (McGill)
Wozniewski, Mike (McGill)

Issues

Berry: As an acoustician and mechanical engineer, my research interests in relation with
CIRMMT activities are all vibroacoustic aspects related to the generation of sound from
musical instruments or audio sources and its propagation in more or less complex
environments. More specifically, over the past 4 years, I have collaborated with CIRMMT in
the context of a VRQ “projet structurant” and as a member of a FQRSC strategic network, on
the following research: (1) piezoelectric loudspeakers with a controllable acoustic directivity;
(2) Adaptive Wave Field Synthesis, an approach for multichannel sound field reproduction
that compensates for the acoustics of the reproduction space.

Guastavino: Perceptual evaluations of spatial audio reproduction techniques in terms of
ecological validity, sound quality, immersion and localization. Recording/reproduction
techniques investigated include Ambisonics (2D and 3D), transaural, stereophony, pairwise
panning and 5.1. Extensions to WFS in progress.
Guastavino, C., & Katz, B. (2004). Perceptual evaluation of multi-dimensional spatial audio reproduction.
Journal of the Acoustical Society of America, 116(2), 1105-1115.
Guastavino, C., Katz, B., Polack, J-D., Levitin, D., & Dubois, D. (2005). Ecological validity of soundscape
reproduction. Acta Acustica united with Acustica, 91(2), 333-341.
Guastavino, C., Larcher, V., Catusseau, G. & Boussard, P. (2007). Spatial audio quality evaluation: Comparing
transaural, ambisonics and stereo. Invited paper at ICAD 2007, Montreal, Canada, June 2007.

Martens: This presentation will review recent work in the perceptual evaluation of auditory
spatial imagery associated with advanced techniques for spatial sound reproduction, paying
particular attention to optimizing multichannel loudspeaker arrays and multichannel
microphone techniques. Though emphasis will be placed upon what has been learned from
the results of scientific investigations (relating listener preferences to auditory attributes), the
presentation will include discussion of artistic exploration of controllable auditory attributes
of virtual sound sources and the virtual acoustic spaces within which they may be located.
Spatial Audio Workshop CIRMMT Atelier sur l'audio spatial

Zatorre: We performed an fMRI study in which subjects listened to environmental noises
with differing degrees of reverberation added. The data indicate that regions of the brain
involved in processing and interpreting reverb information from the environment are similar
to those involved in voice processing (superior temporal sulcus). We propose that this is
because voices involve a source/filter decomposition, which is a similar operation to that
involved in deconvoluting a sound from the echos it produces.

Cooperstock: Where do the opportunities lie for pushing the envelope further on audio
immersion, whether through perceptual cheats (e.g. relying on multimodal cues to compensate
for deficiencies in audio), improved sound spatialization or environment simulation
techniques, wave field synthesis, or rendering through headphones? Can we create acoustic
spaces that replicate the necessary cues of non-trivial environments (either "live" or synthetic)
so as to provide to multiple participants a sufficient degree of perceptual immersion to
achieve suspension of disbelief in the effect, and to do so at sufficiently low latencies as to
enable group interaction?

Settel: We are interested in 3D audio processing, wireless sensing networks
(position/orientation and other), 3D user interface design, and applications involving userspecific
audio rendering (for multiple users) in the arts and telecommunication areas.

McAdams: An interdisciplinary project on the gestural control of spatialization in a concert
setting will be presented. The project involves the implementation and development of
different models of spatialization over a large loudspeaker array, perceptual testing of spatial
resolution (position, movement), perceptually relevant mapping of gesture to spatialization
parameters, and perceptual testing of limits and possibilities of spatializing multiple virtual
sound sources.

Ferguson: My interests have to do with the artistic application of spatialization in the context
of works for instruments and live electronics. I am concerned with the interaction between the
live sound of the instruments on stage and their "disembodied" spatial representations in the
loudspeakers. An important aspect of my thinking has to do with the possible contributions
that spatialization can make to perceived musical tension.

Normandeau: La spatialisation timbrale ou le médium, c’est l’espace. Marshall McLuhan
écrit en 1967 que le médium, c’est le message. Or la question qui se pose à nous aujourd’hui,
soixante après son «invention», c’est quelle est la part du médium dans la musique
électroacoustique, qu’est-ce qui lui appartient en propre et qui n’est pas redevable à la
musique instrumentale? À notre avis, poser la question c’est y répondre : c’est dans
l’apparition d’un art musical de support, à opposer à un art d’interprétation, que réside toute la
spécificité de l’électroacoustique. La communication d’aujourd’hui vise à présenter un aspect
particulier de la musique électroacoustique, la spatialisation sonore et plus encore, la
spatialisation timbrale, qui la détermine comme un médium unique.

Piché: Une installation expérimentale pour la projection musicale sur grappe de haut-parleurs.
Le système consiste en une grille motorisée sur laquelle un ensemble de 32 haut-parleurs peut
être disposé de façon arbitraire. Rapidement reconfigurable, le système permettra l'exploration
et l'expérimentation de différents modèles de diffusion multi-point comme l'ambisonique, la
synthèse par "wave field" et les dômes de diffusion. Les principlaes fonctionalités seront
présentées.