vocoder
An electronic device that imposes the spectral characteristics of a vocal signal onto a synthesiser sound.
In Depth
The vocoder analyses the frequency spectrum of speech or singing and uses that analysis to shape the output of a synthesiser, creating the impression of a talking or singing machine. Originally developed for military speech encryption in World War II, it was adopted by musicians in the 1970s. Kraftwerk, Herbie Hancock, and Daft Punk made iconic use of vocoders. The vocoder differs from Auto-Tune in that it requires a separate carrier synthesiser signal.
The vocoder was invented by Bell Labs in 1938 to compress telephone signals, then used to encrypt Churchill and Roosevelt's wartime conversations before musicians got hold of it.