Patent ID: 8897455
Filing Date: 2014-11-25
Classification: G10L,H04R

Abstract:
1. A method of processing a multichannel signal, the method being implemented by an audio sensing device, said method comprising: for each of a plurality of different frequency components of the multichannel signal, calculating a difference between a phase of the frequency component at a first time in each of a first pair of channels of the multichannel signal, to obtain a first plurality of phase differences; based on information from the first plurality of phase differences, calculating a value of a first coherency measure that indicates a degree to which directions of arrival of at least the plurality of different frequency components of the first pair of channels of the multichannel signal at the first time are coherent in a first spatial sector; for each of the plurality of different frequency components of the multichannel signal, calculating a difference between a phase of the frequency component at a second time in each of a second pair of channels of the multichannel signal, said second pair of channels of the multichannel signal being different than said first pair of channels of the multichannel signal, to obtain a second plurality of phase differences; based on information from the second plurality of phase differences, calculating a value of a second coherency measure that indicates a degree to which directions of arrival of at least the plurality of different frequency components of the second pair of channels of the multichannel signal at the second time are coherent in a second spatial sector; calculating a contrast of the first coherency measure by evaluating a relation between the calculated value of the first coherency measure and an average value of the first coherency measure over time; calculating a contrast of the second coherency measure by evaluating a relation between the calculated value of the second coherency measure and an average value of the second coherency measure over time; and based on which is greatest between the contrast of the first coherency measure and the contrast of the second coherency measure, selecting one between the first and second pairs of channels of the multichannel signal, wherein said multichannel signal is received via a microphone array.