SPEECH ANALYSIS METHOD AND DEVICE FOR SUPPLYING DATA TO SYNTHESIZE SPEECH WITH DIMINISHED SPECTRAL DISTORTION AT THE TIME OF PITCH CHANGE

A method for speech analysis applicable to a speech analysis/synthesis system employed for producing a synthetic speech. Voiced and unvoiced segments of input speech signals X(n) are discriminated. An amplitude information A(.omega.) and a phase information P.sub.X (.omega.) are extracted from the voiced segments of the input speech signals. A pitch period is detected from the voiced segments of the input speech signals. A pulse train S(n) as a sound source information is generated so that its period corresponds on the time scale to the detected pitch period of the input speech signals. A phase information P.sub.S (.omega.) is extracted from the pulse train S(n). A difference P(.omega.) between the phase information P.sub.S (.omega.) of the pulse train S(n) and the phase information P.sub.X (.omega.) of the input speech signal is found and is supplied as the phase information of the desired one-pitch period within the input speech signals.