Sound signal processing apparatus and degree of speech computation method

摘要

Speech likeliness or a degree of speech is determined with a simple configuration or with a small amount of processing, and speech parts are separated from an input sound signal. The input sound signal is subjected to a waveform slicing process in frame units. The increase and decrease rate of a half wavelength in the frame is computed. The rate of a zero cross in the frame is computed. The increase and decrease rate of a half wavelength is computed by determining the rate of the portion where the upward half-wavelength or the downward half-wavelength of the waveform of the input sound signal changes to increase and decrease alternately or to decrease and increase alternately. The degree of speech is determined using each rate. Speech processing for separating or accentuating/attenuating speech and background noise in accordance with the degree of speech is performed on the sound signal for each frame.