Endless pitch illusion

Shepard Tone

Explore octave-stacked tones whose layers fade in and out to create the impression of continuous ascent or descent.

Shepard illusion

Build a rise that returns to its starting point

Each tone stacks sine waves an octave apart; their loudness follows a smooth register envelope, strong in the middle and weak at the extremes.

Hear the loop

  1. Choose a version.
  2. Start the sound.
  3. Change speed and layer count.
  4. Compare glissando, discrete scale, and tritone.
Pitch class
Cycle position
Construction

The perceived motion comes from octave layers fading through a register envelope while the pitch class cycles back to its start.