Periphonic Sound Spatialization in Multi-User Virtual Environments

As a collaboration with the Center for Research in Electronic Arts Technology (CREATE) at the University of California at Santa Barbara (UCSB), this thesis addresses sound spatialization in the AlloSphere, a research environment currently under construction as a shared facility of the California Nanosystems Institute and UCSB’s Media Arts and Technology program. This spherical construction, which has a diameter of approximately 10 meters and accommodates ten to twenty people on a centered bridge, features interactively controllable projection of visual and aural data on its entire inner surface. The theoretical foundations of spatial hearing and a short history of periphonic sound spatialization are presented. An overview of spatialization techniques (Vector Base Panning, Higher Order Ambisonics, holophonic approaches) is given. A Higher Order Ambisonic C++ library for the CSL framework (CREATE Signal library) has been developed together with J. Castellanos and G. Wakefield, which can be used to set up Ambisonic systems up to third order on distributed computing systems. A periphonic loudspeaker layout design strategy is presented. It bases on a hybrid approach of geodesic spheres and minimal energy configurations, allowing to balance the design process between localization homogeneity and psychoacoustical layout optimization. An according Matlab library has been developed to generate loudspeaker layouts and evaluate them in combination with different spatialization algorithms.