Patent ID: 7716044
Filing Date: 2010-05-11
Classification: G10L,H04M,H04R

Abstract:
1. A sound acquisition method for acquiring a signal of sound from each sound source by microphones of plural channels according to the present invention, comprising: a state deciding step including an utterance deciding step of deciding an utterance period from signals acquired by said plural-channel microphones; a sound source position detecting step of detecting the position of said each sound source from said acquired signals when the utterance period is decided in said utterance deciding step; a frequency domain converting step of converting said acquired signals to frequency domain signals; a covariance matrix calculating step of calculating a covariance matrix of said frequency domain acquired signals; a covariance matrix storage step of storing said covariance matrix for each sound source based on the result of detection in said sound position detecting step; a filter coefficient calculating step of calculating filter coefficients of said plural channels based on said stored covariance matrix and a predetermined output level; a filtering step of filtering the acquired signals of said plural channels by filter coefficients of said plural channels, respectively; an adding step of adding together the results of filtering in said plural channels, and providing the added output as a send signal; and an acquired sound level estimating step of estimating the acquired sound level for utterance from said each sound source based on a covariance matrix stored corresponding to said each sound source, and wherein said filter coefficient calculating step includes a step of calculating said filter coefficients of said plural channels based on said covariance matrix stored corresponding to said each sound source and said estimated acquired sound level so that the output level becomes a desired level.