Speech processing apparatus and speech processing method

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.