SonicSenses Lab
Binaural beat demo
Send one steady tone to each ear, a few hertz apart, and most listeners perceive a slow pulsing that is not present in either ear on its own.
Binaural beat demo: how this works, in words
- What it does
- Sends one steady tone to your left ear and a slightly different tone to your right, so the difference between them can be heard as a slow pulse.
- What it accepts
- No input of your own. Both tones are generated on this page. Headphones are needed, because the effect depends on each ear receiving a separate tone.
- What you control
- A carrier frequency control, a beat frequency (the difference in hertz between the ears), play and stop, and a Level slider.
- What changes
- Audio only. A wider difference gives a faster pulse; a narrower one gives a slower pulse. The carrier and beat values are printed as text.
- What it illustrates
- A perceptual effect: the pulse is created by your auditory system combining the two ears, not by anything present in either tone on its own.
- What it does not claim
- It does not show that a beat frequency changes brainwaves, mood, sleep or focus. Evidence on those outcomes is mixed and mostly small-scale, and this page is a demonstration of perception only.
- Keyboard and screen readers
- Frequency controls are native inputs adjustable by keyboard, and the carrier and beat frequencies are announced as text in a polite live region, so the settings are readable without a graph. The pulsing itself is audible only, and headphones are required.
200 Hz left / 206 Hz right · 6 Hz beat
Headphones are required. Over speakers the two tones combine in the air and you hear an ordinary acoustic beat instead, which is a different phenomenon.
What is well established: the perceptual beat itself. It is created in the auditory system when the two ears receive slightly different frequencies, which is why headphones are required.
What is mixed: effects on state. Reviews of human trials report small and inconsistent changes in reported anxiety, attention or mood, with wide variation in methods, dose and blinding.
What is not supported: claims that a specific beat frequency reliably "tunes" brainwaves, treats a medical condition, or produces a guaranteed neurological outcome. Read the fuller summary in binaural beats evidence.
Every Lab demo is generated by your own browser and stops when you leave the page. Start quiet, raise slowly, and see our listening safety guidance. Nothing here is medical advice or a treatment.