Abstract: Pitch-synchronous speech processing invention involves two main steps: 1) divide the speech into pitch periods, or into pseudo pitch periods for unvoiced speech, where the breaks occur, for example, at the first zero-crossing preceding each glottal pulse for voiced speech and at any arbitrary point for unvoiced speech, and 2) compute the log-magnitude of the Discrete Fourier Transform (DFT) of each pitch-period waveform, and interpolate each log-magnitude spectrum to a common regular grid which can accommodate the spectrum of a waveform having the longest pitch period anticipated.