Patent ID: 9247347
Filing Date: 2016-01-26
CPC Classification: G10L,H04R

Claim Text:
1. A noise suppression apparatus for suppressing noise components included in a mixed signal, in which audio components and the noise components are mixed, by spectral subtraction, comprising: a noise estimation unit configured to estimate the noise components included in the mixed signal; a fundamental tone detection unit configured to detect a fundamental frequency of the mixed signal; a factor setting unit configured to set a subtraction factor in the spectral subtraction based on the detected fundamental frequency; and a spectral subtraction unit configured to execute the spectral subtraction for the mixed signal using the set subtraction factor and the estimated noise components, wherein said factor setting unit sets a boundary frequency at the fundamental frequency or a frequency lower than the fundamental frequency, and sets a subtraction factor for a frequency lower than the boundary frequency to assume a value larger than a subtraction factor for a frequency not less than the boundary frequency.