Auto-Tune is an audio processor created by Antares Audio Technologies, which uses a proprietary device to measure and alter pitch in vocal and instrumental music recording and performances through use of a phase vocoder.[2][not in citation given] It was originally intended to disguise or correct off-key inaccuracies, allowing vocal tracks to be perfectly tuned despite originally being slightly off-key.

The processor slightly bends pitches to the nearest true semitone (to the exact pitch of the nearest tone in traditional equal temperament). Auto-Tune can also be used as an effect to distort the human voice when pitch is raised or lowered significantly.[3] The overall effect to the discerning ear can be described as hearing the voice leap from note to note stepwise, like a synthesizer.

Auto-Tune is available as a plug-in for professional audio multi-tracking suites used in a studio setting and as a stand-alone, rack-mounted unit for live performance processing.[4] Auto-Tune has become standard equipment in professional recording studios.[5]