A NOISE SUPPRESSOR AND METHOD FOR SUPPRESSING BACKGROUND NOISE IN NOISY SPEECH, AND A MOBILE STATION
摘要
The invention concerns a voice activity detection device in which an input speech signal (x(n)) is divided in subsignals (S(s)) representing specific frequency bands and noise (N(s)) is estimated in the subsignals. On basis of the estimated noise in the subsignals, subdecision signals (SNR(s)) are generated and a voice activity decision (Vind) for the input speech signal is formed on basis of the subdecision signals. Spectrum components of the input speech signal and a noise estimate are calculated and compared. More specifically a signal-to-noise ratio is calculated for each subsignal and each signal-to-noise ratio represents a subdecision signal (SNR(s)). From the signal-to-noise ratios a value proportional to their sum is calculated and compared with a threshold value and a voice activity decision signal (Vind) for the input speech signal is formed on basis of the comparison. <IMAGE>
申请公布号
WO9722116(A3)
申请公布日期
1997.07.31
申请号
WO1996FI00648
申请日期
1996.12.05
申请人
NOKIA MOBILE PHONES LTD.;VAEHAETALO, ANTTI;HAEKKINEN, JUHA;PAAJANEN, ERKKI;MATTILA, VILLE-VEIKKO