Generating virtual microphone signals using geometrical information gathered by distributed arrays

Conventional recording techniques for spatial audio are limited to the fact that the spatial image obtained is always relative to the position in which the microphones have been physically placed. In many applications, however, it is desired to place the microphones outside the sound scene and yet be able to capture the sound from an arbitrary perspective. This contribution proposes a method to place a virtual microphone at an arbitrary point in space, by computing a signal perceptually similar to the one which would have been picked up if the microphone had been physically placed in the sound scene. The method relies on a parametric model of the sound field based on point-like isotropic sound sources. The required geometrical information is gathered by two or more distributed microphone arrays. Measurement results demonstrate the applicability of the proposed method and reveal its limitations.