Time/pitch scaling using the constant-Q phase vocoder
John Garas, P.C.W. Sommen · TU/e Research Portal · 1998
Playing a recorded audio signal at faster rate than its original rate results not only in shortening the message but also in changing its spectral contents. Time scaling aims at changing the replay rate of an audio signal without impairing the signal’s spectral contents. Traditional phase vocoders used to perform this operation do not take into account the nonuniform characteristics of the human auditory system. An improved phase vocoder system that performs spectral analysis similar to that performed by the human auditory system is presented in this paper. The improved phase vocoder is derived using warping techniques to transform the constant-bandwidth spectral resolution obtained by the ordinary Discrete Fourier Transform to a constant-Q resolution (percentage