Shepard Tone Generator: The Infinite Audio Illusion
Experience the auditory equivalent of a barber pole. Our free Shepard Tone generator creates a sound that rises forever but never gets higher.
The Shepard tone is an auditory illusion that tricks your brain into hearing a sound that ascends (or descends) forever, without the pitch actually getting higher or lower. It is often called the "sonic barber pole."
Shepard Tone Generator
Experience the auditory illusion of a tone that seems to rise (or fall) forever
How It Works
The Shepard tone creates an illusion using multiple sine waves spaced an octave apart. As each tone rises, it fades out while a new lower tone fades in. Your brain blends these together, perceiving an endlessly ascending pitch—even though the frequencies are cycling.
Named after cognitive scientist Roger Shepard, who first described this auditory illusion in 1964.
How It Works
The illusion layers multiple sine waves separated by octaves. As the tones rise:
- Low tones fade in at the bottom.
- Mid-range tones are loudest.
- High tones fade out at the top.
Your brain focuses on the rising movement but misses the subtle fade-ins and fade-outs, creating a seamless loop of "infinite" rising.
Info
Fun Fact: This effect is used in The Dark Knight (Batpod sound) and Super Mario 64 (endless stairs) to create a sense of relentless tension.
The Science
Named after cognitive scientist Roger Shepard, this illusion exploits "pitch class" (the note name, e.g., 'A') vs. "pitch height" (the octave). By keeping the pitch class moving but the overall height ambiguous, your brain assumes the sound is constantly traveling in one direction.
Common Uses
- Film: Hans Zimmer often uses it to build suspense that never resolves (e.g., Dunkirk).
- Music: Pink Floyd ("Echoes") and The Beatles ("A Day in the Life") used similar rising textures.
- Psychology: Used in experiments to test auditory perception.
Warning
Feeling Dizzy? The Shepard tone can be disorienting or induce mild vertigo in some listeners due to the conflict between what you hear and what you expect.
Related Tools
- Binaural Beats — Brainwave entrainment.
- Hearing Test — Check your frequency range.
- White Noise — Mask distracting sounds.