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The Project AUDIENCE

Sounding with AUDIENCE

Scientific and Technological Production

Call for Works, Contributions and Opportunities

Team, Colaboration, Support, Partners, Associated Projects and Groups



The Project AUDIENCE

The project AUDIENCE was initiated in 2003 having as objective the research of flexible and scalable immersive (surround) audio systems for applications in complete virtual reality, that is, applications where the sound and the image are complementary and acting jointly to produce an experience of immersion in the virtual world.

For this, it was conceived an architecture for the audio chain involving from the production, the distribution, till the final presentation (reproduction), taking care of the requirements to generate the spatial audio of a virtual scene.

Faria (2005) proposed a modular architecture for auralization, oriented to independent functional layers. In this, there are 4 main groups of functions (processes) to be executed in the spatial audio production and reproduction chain:

  • the scene production, contemplating the composition of the auditory scene through the description of the environment, the sound sources and other objects with their respective properties, audiovisual positions and parameters;
  • the acoustic scene simulation (or rendering), contemplating the functions and techniques responsible for calculating the acoustic propagation of the sounds in scene, and getting an auditory representation of the sound at a certain hearing position;
  • the spatial sound codification of the scene, contemplating the generation of the transport media that contains the temporal and space description of the sounds in scene;
  • the decoding and reproduction of the auditory scene (multichannel reproduction), responsible for the spatial audio decoding and for the generation of the sounds that feed each channel (each loudspeaker) used in the configuration or reproduction setup chosen by the user (ex: stereo, quadriphonic, biaural, ring with 8 loudspeakers, surround 5.1, etc.).

The main functions chain for auralization used in the AUDIENCE system

Each functional group is properly implemented within one "functional layer" in the AUDIENCE system, as shown in figure below:

AUDIENCE functional layers architecture, showing possible signals between layers and audio output modes

This approach presents several advantages from the point of view of implementation, for decoupling in a systematic way the main processes of the chain, allowing that they are carried through by independent modules (in software and/or the hardware). A consequence of its adoption is in the necessity of specifying (or standardizing) sets of (interface) signals, parameters and valid messages that must pass from a layer to another, so as to make compatible the output of one layer with the input ports of another.

Once a representative set of signals to be adopted is defined, the solutions developers will be able independently to specialize or to focus their efforts in the development of components for one functional layer independently from the others, stimulating the diversification of solutions for each layer. The user or designer of a final auralization system will be able then to adopt the desired solutions in each layer, selecting component of different developers, and extending the possibility of synthesis of a component system that combines the techniques that he/she selects to use.

Based in this architecture, this project has as main objective the development of a modular and scalable integrated software and the hardware system for production, distribution and reproduction of spatial/multichannel audio. The deployment of a family of software distributions of auralization machines is foreseen, gradually incorporating improvements in the usability, integrability and advanced functionalities. Parallel, initiatives for the conception of new products with industrial partnerships are in progress.


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