ABSTRACT

For most of the history of recorded sound, time and pitch have been inextricably linked. A few professional products make tiny edits automatically to change timing, and then apply as little pitch shift and speed change as possible. Large pitch shifts can have problems, even if the software does the job without glitches. Despite the ability of today's systems to change time or pitch independently, doing it the old-fashioned way —changing both together —is sometimes more desirable. The time and pitch manipulations are used as a special effect rather than a problem solver. Most audio editors come with a pitch shifter that can preserve duration while changing the pitch, or a tempo changer that changes duration without affecting frequencies. Pitch shift is useful as a corrective device. Special shifters are available that analyze singers' voices, spot when they're off-key, and nudge them back.