Binaural beats, free in your browser
Two steady tones, one in each ear. Your brain hears a slow beat that isn’t in either one. Put on headphones and press play.
Headphones needed: each ear has to hear only its own tone. On a speaker you’ll hear an ordinary wobble instead.
The Lab adds visuals, timed sessions and a library of beats for sleep, focus and calm.
How binaural beats work
MeasuredPlay 200 Hz in your left ear and 210 Hz in your right, and you hear a soft wobble 10 times a second: the difference between the two. The wobble isn’t in the air. It’s made where the signals from your two ears meet in the brainstem. Heinrich Wilhelm Dove described the effect in 1839, and Gerald Oster brought it to wide attention in Scientific American in 1973[1]. The beat is easiest to hear with tones below about 1,000 Hz (strongest around 400–500 Hz) and fades above that. The presets here use lower tones, 120 to 250 Hz, because they’re softer and easier to relax to.
The five bands
| Band | Beat | The brain state it’s named after |
|---|---|---|
| Delta | 0.5–4 Hz | Deep sleep |
| Theta | 4–8 Hz | Drowsy, drifting off, deep meditation |
| Alpha | 8–13 Hz | Awake and relaxed, eyes closed |
| Beta | 13–30 Hz | Alert, busy thinking |
| Gamma | 30 Hz and up | Focused attention (40 Hz is the famous one) |
MeasuredThese are the rhythms of brain waves measured with EEG. Whether a beat pulls your brain waves into that band is the open question below.
What the research shows
StudiesA 2019 meta-analysis pooled 22 studies and found a medium overall effect (g = 0.45) on memory, attention, anxiety and pain. The studies differed in design and many were small[2]. A 2023 systematic review checked the core idea, that a beat pulls brain waves toward its own rate, and found the evidence inconsistent: of 14 studies, 5 supported it, 8 contradicted it and 1 was mixed[3].
Short version: some people find binaural beats relaxing or focusing, the effects in studies are medium on average, the studies vary a lot, and the brain-wave story isn’t settled.
How to listen
- Use headphones or earbuds. Left and right must stay separate.
- Keep the volume low. The beat works at a whisper.
- Give it 15–30 minutes and use the timer.
- Don’t listen while driving or doing anything that needs your full attention.
Want a plan instead of a dial?
Calm Week is seven short sessions for a quiet break, with beats and tones side by side. Day 1 is free.
Questions
Do binaural beats work without headphones?
Not as binaural beats. Through speakers both tones reach both ears and mix in the air, so you hear an ordinary “monaural” beat: a real wobble in loudness. Some people prefer that, and the Lab’s pulse sessions make it on purpose.
Which beat is best for sleep, and which for focus?
For sleep, people commonly use delta (0.5–4 Hz) or theta (4–8 Hz): see binaural beats for sleep. For focus, people commonly use alpha around 10 Hz or low beta around 14–18 Hz. For 40 Hz, read the 40 Hz guide first: the famous studies used a different kind of sound.
Are binaural beats safe?
We haven’t found serious side effects reported in the studies above. Keep the volume low and don’t listen while driving. If you have epilepsy, ask your doctor before using pulsing or beating sounds.
Why do the presets use different tones?
The tone sets the pitch you hear; the difference between the ears sets the beat. Lower tones suit sleep sessions, and beats only work when the tones stay below about 1,000 Hz.
Sources
- Oster G. Auditory beats in the brain. Scientific American 229(4):94–102 (1973). doi:10.1038/scientificamerican1073-94
- Garcia-Argibay M, Santed MA, Reales JM. Efficacy of binaural auditory beats in cognition, anxiety, and pain perception: a meta-analysis. Psychological Research 83:357–372 (2019). doi:10.1007/s00426-018-1066-8
- Ingendoh RM, Posny ES, Heine A. Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity, and the implications for psychological research and intervention. PLOS ONE 18(5):e0286023 (2023). doi:10.1371/journal.pone.0286023