⚠️ Note: This illusion can be disorienting. Start at low volume and stop if you feel uncomfortable. Not recommended for those prone to vertigo or motion sickness.
What is a Shepard Tone?
A Shepard tone is an auditory illusion that creates the impression of a tone that continuously ascends or descends in pitch, yet never actually gets higher or lower.
Named after cognitive scientist Roger Shepard, it's created by layering multiple sine waves separated by octaves, with carefully controlled volume levels that fade in and out.
How Does It Work?
The illusion works by layering 8 sine waves, each an octave apart. As one tone rises and fades out at the top, another fades in at the bottom, creating a seamless loop.
Your brain focuses on the middle frequencies and ignores the fading extremes, creating the illusion of infinite ascent or descent.
The "Sonic Barber Pole"
The Shepard tone is often called the "sonic barber pole" because it's the auditory equivalent of the visual barber pole illusion - stripes that appear to move continuously upward but never reach the top.
Both illusions exploit the way our brains process cyclical patterns.
Famous Uses
- • Film: Dunkirk, The Dark Knight (Hans Zimmer)
- • Games: Super Mario 64 (endless stairs)
- • Music: Pink Floyd, Radiohead
- • Research: Psychoacoustics studies
Psychoacoustic Effect
The Shepard tone demonstrates how our auditory system processes pitch and how our brain can be "tricked" by carefully constructed sounds.
It reveals the difference between physical sound waves and our perception of them.
Tips for Best Experience
- • Use headphones: Better stereo effect
- • Start slow: Easier to perceive the illusion
- • Close your eyes: Focus on the sound
- • Listen for 30+ seconds: Let the illusion sink in
- • Try both directions: Different experiences
Try Our Other Audio Tools
Online Tone Generator
Generate single tones with precise frequency control. Perfect for quick audio testing and tuning.
Professional Tone Generator
Advanced tone generation with enhanced controls for audio engineers and professionals.
Multiple Tone Generator
Play multiple frequencies simultaneously with independent volume and panning controls.
Frequency Sweep Generator
Create linear or exponential frequency sweeps for speaker testing and room acoustics analysis.
Binaural Beats Generator
Generate binaural beats for meditation, focus, and relaxation. Requires headphones for proper effect.
DTMF Tone Generator
Generate telephone dial pad tones (Dual Tone Multi Frequency). Interactive touch-tone dial pad.
Online Metronome
Professional metronome with tap tempo, time signatures, subdivisions, and tempo trainer for musicians.
Noise Generator
Generate white, pink, and brown noise for sleep, focus, tinnitus relief, and speaker burn-in.
Instrument Tuner
Reference tuning notes for guitar, bass, ukulele, violin, cello, and more at concert pitch (A440).
Subwoofer Test
Test your subwoofer with a 60-second frequency sweep (150Hz-1Hz) and individual bass test tones.
Hearing Test
Test your hearing range from 8kHz to 20kHz. Find your hearing age and compare with averages.
Solfeggio Frequencies
Ancient healing tones including 528Hz (DNA repair). For meditation, chakra activation, and spiritual healing.
Speaker Balance Test
Test stereo balance with panning control and left/right channel testing. Perfect for speaker setup.
Pitch Pipe
Chromatic pitch pipe with all 12 notes across 3 octaves. Perfect for singers, choirs, and a cappella groups.
Mosquito Tone
Can you hear the mosquito tone? High-frequency test (15-20kHz) that only young people can hear. Find your hearing age!
Soundscape Builder
Create relaxing ambient soundscapes with singing bowls, nature sounds, and binaural beats.