Patent ID: 7394907

Claim:
A system for finding the direction to a sound source from a microphone array in a prescribed search area, comprising: a microphone array having a plurality of audio sensors; a general purpose computing device; a computer-readable medium having computer-executable instructions, wherein the computing device is directed by the instructions of the computer-readable medium to, (a) package the signals produced by the array microphones into frames, (b) select the frames representing the earliest captured frame of each microphone signal which have not been previously processed, (c) subject the selected frames to a noise suppression procedure, (d) classify the frames based on whether they exhibit evidence of a significant sound source, (e) whenever it is found that the frames do not exhibit evidence of a significant sound source, repeat program modules (b) through (e) as appropriate, (f) whenever it is found that the frames do exhibit evidence of a significant sound source, compute a full spectrum energy comprising an energy value for each of a prescribed set of audio frequency sub-bands within an overall frequency band for a beam in each of a prescribed number of directions, wherein a beam represents a region surrounding a direction extending away from the microphone array wherein sounds originating within that region remain unaffected, while sounds originating outside that region are suppressed, and wherein the prescribed number of directions represent a set of search directions extending away from the microphone array which when a beam is associated with each of the search directions covers the entire search area without significant overlap between adjacent beams extending along those directions, and for each computed energy value, apply a weighting factor associated with the frequency sub-band of the computed energy value, from a set of weighting factors comprising one for each of said set of audio frequency sub-bands, to the computed energy value, wherein each weighting factor reflects an energy level which is expected to be exhibited by the sound source at the frequency sub-band associated with the weighting factor relative to all the other sub-bands within the overall frequency band, (g) identify the search direction exhibiting the maximum energy across the overall frequency band, and (h) designate the maximum energy direction as the direction to the sound source.