| 摘要 |
PROBLEM TO BE SOLVED: To allow for appropriate suppression of the echo components depending on the environment, by taking account of the reverberation time of each frequency band.SOLUTION: An echo suppressor includes an echo transmission characteristics estimation unit (14) for estimating the transmission characteristics of an echo signal from the power spectrum of a received signal and the power spectrum of a sound collection signal, an echo signal power spectrum estimation unit (15) for estimating the power spectrum of an echo signal on the basis of the transmission characteristics of the echo signal and the power spectrum of a received signal, and an echo suppression gain calculation unit (16) for calculating the echo suppression gain from the echo signal power spectrum and the power spectrum of a sound collection signal. The echo signal power spectrum estimation unit (15) sets an oblivion coefficient for each frequency band from the reverberation time for each frequency band, and estimates the power spectrum of an echo signal while taking account of the power spectrum of an echo signal in the past, by using the oblivion coefficient thus set. |
