Phase vocoding is a complex signal-processing technique which includes elements of LPC (Linear Predictive Coding). It uses continuous and overlapping Fourier transforms of a sound for several related objectives, ranging from resynthesis, and timbral interpolation from one sound to another, to ’time-stretching’ (altering the speed of a sampled sound without affecting the pitch) and ’pitch shifting’ (transposition of a sound without altering the speed). The phase vocoder is so called to distinguish it from the more familiar ’channel’ vocoder. (Source - Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press.)
See also:
FFT, Linear Predictive Coding, Time-stretchingBibliography:

