Speech processing apparatus and speech processing method

摘要

A signal portion is extracted per frame having a specific duration from an input signal, thus generating a per-frame input signal. The per-frame input signal in the time domain is converted into a per-frame input signal in the frequency domain, thereby generating a spectral pattern of spectra. Peak spectra having peaks are detected in the spectral pattern. A harmonic spectrum is determined, in the peak spectra, having a harmonic structure showing a relationship between a fundamental pitch and a harmonic overtone.

主权项

1. A speech processing apparatus comprising:
a frame extraction unit configured to extract a signal portion per frame having a specific duration from an input signal that includes periodic non-speech segments, thus generating a per-frame input signal; a spectrum generation unit configured to convert the per-frame input signal in a time domain into a per-frame input signal in a frequency domain, thereby generating a spectral pattern of spectra; a peak detection unit configured to detect peak spectra having peaks in the spectral pattern by determining at least one spectrum of a first spectrum group of a predetermined number of spectra as the peak spectrum based on a predetermined criterion if an energy ratio of total energy of the first spectrum group to total energy of a second group of the predetermined number of spectra, next to the first spectrum group in the spectral pattern, is equal to or higher than a predetermined threshold level; and a harmonic-overtone determination unit configured to determine a harmonic spectrum, in the peak spectra, having a harmonic structure showing a relationship between a fundamental pitch and a harmonic overtone based on a barycentric frequency weighted by energy of each of the peak spectra; and a noise attenuation unit configured to attenuate energy corresponding to spectra obtained by removing the harmonic spectrum from the peak spectra in the spectral pattern.