FFT Implementation of the Phase Vocoder

In the 1970s, the phase vocoder was reimplemented using the FFT for increased computational efficiency by Portnoff [201]. The FFT window (analysis low-pass filter) was also improved to yield exact reconstruction of the original signal when synthesizing without modifications. Shortly thereafter, the FFT-based phase vocoder was adopted as the analysis method of choice for additive synthesis in computer music [176]. Since then, numerous variations and improvements of the phase vocoder have appeared, e.g., [95,204,133,131,135,134,132]. For an excellent introductory tutorial, see [61]. A summary of vocoder research from the 1930s to the 60s appears in a review article by Manfred Schroeder [227].

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About the Author: Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.