RASPUTIN

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RASPUTIN is a collaborative fundamental research project (PRCE) at the intersection of. digital sciences and technologies. and. psychology, that aims at reducing the cognitive complexity of navigation for the blind in a new interior environment through digital simulations and explorations using virtual reality with 3D audio. These explorations make it possible to mentally create cognitive maps of these environments not yet physically explored. The main technical challenge of the project is to generate a realistic audio rendering of a building (auditory virtual environment) in real-time using, on the one hand, the spatialization library Spat~ and, on the other hand, the Evertims library for the simulation of acoustic propagation in a digital model that describes the architectural parameters of a building. The topology of the locations of interest has prompted us to examine how these coupled volumes can be simulated and auralised effectively. More specifically, the properties of delayed reverberation in such locations make auralisation challenging as they entail the use of multi-exponential decay reverberators. This study led us to propose such a reverberator, based on a Feedback Delay Network (FDN), for which the decay characteristics can be controlled by physical parameters reflecting the coupling effects between the volumes. For this purpose, an acoustic radiosity model has been proposed to account for the heterogeneity and anisotropy of the reverberated acoustic intensity within such volumes and its dependence on the location of sources and receivers. In particular, the model makes it possible to control the way in which the source power is distributed between the different inputs of the reverberator according to its position and orientation in the volume. Similarly, it is possible to estimate how the different outputs of the reverberator must be weighted to obtain the receiver signal. IRCAM's Team : <a href="https://www.ircam.fr/recherche/equipes-recherche/eac/">Acoustic and Cognitive Spaces</a> <img src="/media/uploads/recherche/projets/Rasputin/rasputin1.png" alt="© Ircam-Centre Pompidou" width="486" height="300" style="margin-right: 10px;" /><img src="/media/uploads/recherche/projets/Rasputin/rasputin2.png" alt="© Ircam-Centre Pompidou" width="419" height="300" /> Modeling the acoustic intensity distribution within the volume. Left: distribution of the irradiation density at the walls in the case of two coupled volumes in free decay regime. Large variations can be observed, especially near the opening. Right: evolution of the parameter governing the relative weighting of the outputs of the multi-exponential decay reverberator as a function of the location of the receiver. Similar mappings can be made to control the power distribution of a source to the reverberator inputs as a function of its location. <img src="/media/uploads/logos recherche/anr-finance.jpg" alt="" width="60" height="63" />

RASPUTIN is a collaborative fundamental research project (PRCE) at the intersection of. digital sciences and technologies. and. psychology, that aims at reducing the cognitive complexity of navigation for the blind in a new interior environment through digital simulations and explorations using virtual reality with 3D audio.

These explorations make it possible to mentally create cognitive maps of these environments not yet physically explored.
The main technical challenge of the project is to generate a realistic audio rendering of a building (auditory virtual environment) in real-time using, on the one hand, the spatialization library Spat~ and, on the other hand, the Evertims library for the simulation of acoustic propagation in a digital model that describes the architectural parameters of a building.

The topology of the locations of interest has prompted us to examine how these coupled volumes can be simulated and auralised effectively. More specifically, the properties of delayed reverberation in such locations make auralisation challenging as they entail the use of multi-exponential decay reverberators.

This study led us to propose such a reverberator, based on a Feedback Delay Network (FDN), for which the decay characteristics can be controlled by physical parameters reflecting the coupling effects between the volumes. For this purpose, an acoustic radiosity model has been proposed to account for the heterogeneity and anisotropy of the reverberated acoustic intensity within such volumes and its dependence on the location of sources and receivers. In particular, the model makes it possible to control the way in which the source power is distributed between the different inputs of the reverberator according to its position and orientation in the volume. Similarly, it is possible to estimate how the different outputs of the reverberator must be weighted to obtain the receiver signal.

IRCAM's Team : Acoustic and Cognitive Spaces

Modeling the acoustic intensity distribution within the volume.
Left: distribution of the irradiation density at the walls in the case of two coupled volumes in free decay regime. Large variations can be observed, especially near the opening. Right: evolution of the parameter governing the relative weighting of the outputs of the multi-exponential decay reverberator as a function of the location of the receiver. Similar mappings can be made to control the power distribution of a source to the reverberator inputs as a function of its location.