Editing Shepard tone (section)

{{Short description|Auditory illusion}}
{{Use dmy dates|date=October 2020}}
[[File:Shepard Tones spectrum linear scale.png|thumb|right|350px|A [[spectrogram]] of ascending Shepard tones on a linear frequency scale]]

A '''Shepard tone''', named after [[Roger Shepard]], is a sound consisting of a [[superposition principle|superposition]] of [[sine wave]]s separated by [[octave]]s. When played with the bass [[Pitch (music)|pitch]] of the tone moving upward or downward, it is referred to as the ''Shepard scale''. This creates the [[auditory illusion]] of a tone that seems to continually ascend or descend in pitch, yet which ultimately gets no higher or lower.<ref name="Shepard1964" />