Efficient rendering of directional sound sources in wave field synthesis

Wave field synthesis (WFS) is a spatial audio reproduction technique that uses arrays of loudspeakers for the physical creation of the sound field of a virtual source. Besides basic source types such as monopoles, the reproduction of virtual sources with angle- And frequency-dependent directivity characteristics attracts increasing interest. While several synthesis approaches for directional sources have been proposed in recent years, the corresponding audio signal processing has not been considered so far. However, since directional sources typically require a nontrivial filtering operation for each combination of a virtual source and a loudspeaker, straightforward implementation creates major complexity and scalability problems. This paper proposes an efficient processing structure for rendering directional sources using time-frequency signal processing. Integrating the building blocks of a fast convolution method into the WFS rendering algorithm enables the reuse of transform operations, resulting in significant complexity reductions. In this way, this paper demonstrates the advantages of time-frequency processing for a given rendering application by exploiting the performance characteristics of signal processing operations in the two domains. Copyright© (2012) by the Audio Engineering Society.