Spatial processing of sound in MPEG-4 virtual worlds

MPEG-4 is a standard for interactive multimedia applications, where tools are specified for presenting sound in 3-D virtual scenes. This includes parametric representations of 3-D sound source models and the environment where the sound is heard. This article gives an overview on how interactive sound environments are parametrized in the scene description language of MPEG-4. Furthermore, DSP issues for the implementation of the acoustic environment are discussed.