From 1976 through 1989, Dr. Andy Hildebrand worked for the oil industry, interpreting seismic data. By sending sound waves into the ground, he could detect the reflections, and map potential drill sites. Dr. Hildebrand studied music composition at Rice University, and then developed audio processing tools based on his knowledge in seismic data analysis. He was a leading developer of a variety of plug-ins, including MDT (Multiband Dynamics Tool), JVP (Jupiter Voice Processor) and SST (Spectral Shaping Tool). At a dinner party, a guest challenged him to invent a tool that would help her sing in tune. Based on the phase vocoder, Hildebrand’s Antares Audio Technologies released Auto-Tune in late 1996.
Auto-Tune was intended to correct or disguise off-key vocals. It moves the pitch of a note to the nearest true semitone (the nearest musical interval in traditional, equal temperament Western tonal music), thus allowing the vocal parts to be tuned. The original Auto-Tune had a speed parameter which could be set between 0 and 400 milliseconds, and determined how quickly the note moved to the target pitch. Engineers soon realised that by setting this ‘attack time’ very short, Auto-Tune could be used as an effect to distort vocals, and make it sound as if the voice leaps from note to note in discrete steps. It gives it an artificial, synthesiser like sound, that can be appealing or irritating depending on taste. This unusual effect was the trademark sound of Cher’s 1998 hit song, ‘Believe.’
Like many audio effects, engineers and performers found a creative use, quite different from the intended use. As Hildebrand said, “I never figured anyone in their right mind would want to do that.” Yet Auto-Tune and competing pitch correction technologies are now widely applied (in amateur and professional recordings, and across many genres) for both intended and unusual, artistic uses.