Binaural beat generator
This generator makes two pure tones live in your browser, one for each ear. Put on stereo headphones, switch it on, and turn difference: the slow pulse you hear is a binaural beat, and its rate is the difference between the two tones.
Put headphones on, then switch it on.
- left ear
- Hz
- right ear
- Hz
How to use it
- Put on stereo headphones or earbuds. Speakers won't work: the two tones have to reach your ears separately.
- Turn your volume down, then press Switch on. The generator fades in quietly.
- Drag the difference knob up (or focus it and use the arrow keys). At 0 Hz both ears hear the same tone. At 7 Hz you hear a pulse seven times a second.
- Drag pitch to move both tones up or down. Lower pitches tend to feel softer; the beat is easiest to hear below about 1,000 Hz.
What the numbers mean
Pitch is the tone your left ear hears, in hertz. Difference is how much higher the tone in your right ear is. The beat you perceive has the rate of the difference: 200 Hz and 207 Hz give a 7 Hz beat.
The bottom line on the scope is the two tones added together, which is what a single speaker would play. Through headphones that sum never exists in the air. It is put together by your hearing, which is why the effect is called binaural.
| Name | Difference between the ears | Usually used for |
|---|---|---|
| Delta | 0.5–4 Hz | Winding down at night |
| Theta | 4–8 Hz | Rest, drifting attention |
| Alpha | 8–13 Hz | Calm, easy focus |
| Beta | 13–30 Hz | Alert work |
| Gamma | 30 Hz and up | Hard to hear as a beat at all |
What makes this different from a recording
Most binaural beat tracks are files: fixed pitch, fixed beat, compressed audio. Lossy compression and Bluetooth can smear the small difference between the channels. Here the tones are computed sample by sample as you listen, so the difference is exact and you can change it while it plays.
The binaural app for iPhone works the same way, and goes further: sessions that move through several beat rates, a check of each ear, pulsed tones for people who can't pick out the binaural beat, and coloured noise.
Keep it safe
Keep the volume low; louder is not stronger. Don't listen while driving or doing anything that needs your full attention. If you have epilepsy, a history of seizures, or a neurological or heart condition, ask a clinician before using audio stimulation.
Questions people ask
- Is this binaural beat generator free?
- Yes. It runs entirely in your browser, with no account, no download and no time limit.
- Do I need headphones?
- Yes. A binaural beat only exists when each ear hears a different tone. Through speakers the tones mix in the air and you hear an ordinary acoustic beat instead.
- What frequency should I set?
- There is no single correct setting. Studies have used beats from about 2 Hz to 40 Hz. Lower rates (delta, theta) are usually chosen for winding down and higher rates (beta) for alert work, but the evidence that any rate produces a reliable effect is mixed. Choose what is comfortable to listen to.
- Why can't I hear a beat?
- Check that both earbuds are in and playing, that the difference is above about 1 Hz and below about 30 Hz, and that mono audio is switched off in your device's accessibility settings. Some people find binaural beats faint; that is normal.
- Does it work on a phone?
- Yes, in any modern mobile browser with wired or wireless stereo headphones. Drag a knob up and down to turn it.
Sources
- Oster, G. (1973). Auditory beats in the brain. Scientific American, 229(4), 94–102.
- Ingendoh, R. M., Posny, E. S., & Heine, A. (2023). Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity. PLOS ONE, 18(5), e0286023. doi.org/10.1371/journal.pone.0286023