Real Time Capture of Audio Images and their Use with Video

Spherical microphone arrays provide an ability to compute the acoustical intensity corresponding to different spatial directions in a given frame of audio-data. These intensities may be exhibited as an image and these images updated at a high frame rate to achieve a video stream if the data capture and intensity computations can be performed sufficiently quickly, there by creating a frame-rate audio camera. We describe how such a camera can be built and the processing done sufficiently quickly using graphics processors. The joint processing of captured frame-rate audio and video images enables applications such as visual identification of noise sources, beamforming and noise-suppression in video conferencing and others, provided it is possible to account for the spatial differences in the location of the audio and the video cameras. Based on the recognition that the spherical array can be viewed as a central projection camera it is possible to perform such joint analysis. We provide several examples of real-time applications.