Speech coding based on determining a noise contribution from a phase change

摘要

An audio equivalent signal is coded by determining a noise value for harmonic frequencies. The noise value is determined by the change of phase of the harmonics in successive segments of the signal. The noise value for a harmonic frequency represents a contribution of a periodic component and an aperiodic component to the segment at the harmonic frequency. To this end, the pitch development of the signal is determined, and the signal is broken into segments of, e.g., one or two pitch periods wide. For each of the analysis segments an amplitude value and a phase value is determined for the harmonic frequencies. The noise value for each of the harmonics is determined by comparing the phase value for the harmonic of the segment to a corresponding phase value for at least one preceding or following segment. Each segment is coded as the amplitude value and the noise value for each of the harmonics. The method is preferably used for speech synthesis.