An alternative solution for positioning sound sources in loudspeaker-based virtual environments

In auditory virtual environments it is often required to position an anechoic point source in three-dimensional space. When sources in such applications are to be displayed using multichannel loudspeaker reproduction systems, the processing is typically based upon simple amplitude-panning laws. This paper describes an alternative approach based on an array of virtual microphones. The aim of the system architecture design was to comply with the expectations of audio engineers and to create sound imagery similar to those associated with standard sound recording practice. In the newly designed environment, the microphones, with adjustable directivity patterns and axis orientations, can be spatially placed as desired. This way, time-delay panning can be included by simulating a non-coincident microphone array. By the use of omnidirectional microphones the panning is almost solely based on time-delay panning and thus performance can take advantage of the precedence effect. Also, the proposed architecture is flexible enough to include classic amplitude panning laws by translating the requested panning law into physically non-existing microphone directivity patterns. Moreover, the virtual directivity patterns do not have to be rotationally symmetrical. [Work supported by VRQ.]