Patent ID: 9236060
Filing Date: 2016-01-12
CPC Classification: G10L,H04R

Claim Text:
1. A noise suppression device for suppressing noise, comprising: a phase difference utilization range computation section that, based on a predetermined relationship between a sampling frequency and an inter-microphone distance between a plurality of microphones contained in a microphone array, computes, as a phase difference utilization range, a frequency band in which phase difference for each frequency between input sound signals stays within a predetermined range without exhibiting phase rotation, the input sound signals containing the noise and a target voice that are input from each of the plurality of microphones; an amplitude condition computation section that, based on an amplitude ratio or an amplitude difference for each frequency between the input sound signals, computes amplitude conditions to determine whether or not the input sound signals are the noise or the target voice based on the inter-microphone distance and a position of a sound source of the target voice; a phase difference derived suppression coefficient computation section that, over the phase difference utilization range computed by the phase difference utilization range computation section, computes, for each frequency, a phase difference derived suppression coefficient based on a phase difference; an amplitude ratio derived suppression coefficient computation section that computes, for each frequency, an amplitude ratio derived suppression coefficient based on the amplitude ratio or the amplitude difference, and based on the amplitude conditions computed by the amplitude condition computation section; and a suppression section that suppresses the noise contained in the input sound signals based on a suppression coefficient determined using the phase difference derived suppression coefficient and the amplitude ratio derived suppression coefficient.