Patent ID: 7286980

Claim:
A speech processing apparatus comprising: a frequency dividing section that divides a speech spectrum of an input speech signal into predetermined frequency bands; a speech identifying section that identifies whether or not each frequency band of the speech spectrum includes a speech component based on the frequency-divided speech spectrum and a noise base that is a spectrum of a noise component; a comb filter generating section that generates a comb filter in which frequency bands containing speech components are passed and frequency bands containing non-speech components are attenuated; a pitch frequency estimating section that estimates a speech pitch frequency; a pitch modifying section that modifies the width of pitch harmonics in the comb filter based on the speech pitch frequency and the divided speech spectra; a noise suppressing section that multiplies attenuation coefficients that are based on frequency characteristics of the comb filter with the modified width of pitch harmonics and sets the attenuation coefficients of the respective predetermined frequency bands, and suppresses a noise component of the divided speech spectra by multiplying the divided speech spectra by the attenuation coefficients of the corresponding frequency bands; and a frequency combining section that combines the frequency-divided speech spectrum in which the noise component is suppressed with a speech spectrum continuous in a frequency region.