Simple pitch-dependent algorithm for high-quality speech rate changing
Edward P. Neuburg · The Journal of the Acoustical Society of America · 1978
A new time-domain method is described for speeding up or slowing down speech without changing its quality; spectral shape and pitch contours are preserved. The method is easily implementable in real time, and is effective for noisy speech. It consists of a simple pitch detector followed by an algorithm that discards (or repeats) pieces of speech equal in length to a pitch period. The method is not pitch synchronous. Rate changes from 0.5 to 2.0 sound natural; slow down to 0.1 is intelligible.