A linear filter for time scaling of speech

The authors present a new method for time scaling of speech signals based on scaling the short-time Fourier transform (STFT) along the time axis while keeping it unchanged along the frequency axis. Because the resultant time-frequency function is not an admissible STFT, they project it on the space of admissible STFTs, i.e., they find a signal whose STFT best approximates the time-frequency function. The time-scaled signal is related to the original signal by a linear periodically-time-varying filter, which is simple to implement. High quality time-scaled words and sentences have been obtained using this method