South Park creators Trey Parker and Matt Stone have used pitch shifting for most of their characters throughout the show's run. The Eventide H910 Harmonizer was used to downward pitch-shift the characters' voices back to normal after the episode was sped up. In the '70s, reruns of shows like I Love Lucy were sped up in order to run more advertisements during commercial breaks. Voice artist Mel Blanc used pitch shifting techniques to create the voices of Tweety and Daffy Duck. Alvin and the Chipmunks recordings with David Seville (aka Ross Bagdasarian) were created by recording vocal tracks at slow speeds, then playing them back at normal speeds. Numerous cartoons have used pitch shifters to produce distinctive animal voices. Pitch shifting may raise or lower all sounds in a recording by the same amount, whereas in practice, pitch correction may make different changes from note to note. Pitch correction is a form of pitch shifting and is found in software such as Auto-Tune and Melodyne to correct intonation inaccuracies in a recording or performance. Older digital processors could often shift pitch only in post-production, whereas many modern devices using computer processing technology can change pitch values virtually in real time. In digital recording, pitch shifting is accomplished through digital signal processing.

On November 10, 1976, Eventide filed a trademark registration for 'Harmonizer' and continues to maintain its rights to the Harmonizer trademark today. The Eventide H910 Harmonizer, released in 1975, was one of the first commercially available pitch-shifters and digital multi-effects units. Pitch shifters are included in most audio processors today.Ī harmonizer is a type of pitch shifter that combines the pitch-shifted signal with the original to create a two or more note harmony.

Simple pitch shifters raise or lower the pitch by one or two octaves, while more sophisticated devices offer a range of interval alterations. For example, a pitch shifter set to increase the pitch by a fourth will raise each note three diatonic intervals above the notes actually played. For other uses, see Harmonizers (disambiguation).Ī pitch shifter is a sound effects unit that raises or lowers the pitch of an audio signal by a preset interval.

Eventide h910 harmonizer usage