Autodirective microphone systems for natural communication with speech recognizers
James L. Flanagan, Richard J. Mammone, Gary W. Elko · 1991
Two technological advances support new sophistication in sound capture; namely, high-quality low-cost electret microphones and high-speed economical signal processors. Combined with new understanding in acoustic beamforming, these technologies permit spatially-selective transduction of speech signals several octaves in bandwidth. Spatial selectivity mitigates the effects of noise and reverberation, and digital processing provides the capability for speech-seeking, autodirective performance. This report outlines the principles of autodirective beamforming for acoustic arrays, and it describes two experimental implementations. It also summarizes the direction and emphasis of continuing research.