OneTaskBy Tim King · Updated
Binaural Beats Generator
Set Carrier and Beat Frequency, Free Online
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How the Binaural Beats Generator works
This binaural beats generator plays a different tone in each ear. Put on headphones, set a carrier tone and a beat frequency, and press Play. The left ear gets the carrier minus half the beat, the right ear the carrier plus half the beat, and because each ear hears only one steady tone the slow throb you perceive is made inside your head rather than in the air. The graph shows the beat envelope, the readout names the brainwave band the beat falls in, and a pink noise slider adds a soft wash for people who find a bare tone tiring. The timer counts how long the session has run.
Binaural beats generator: what a binaural beat is
Play two tones a few hertz apart through a loudspeaker and you hear a real, physical beat: the waves add and cancel and the volume wobbles at the difference frequency. Play the same two tones to separate ears and no mixing happens in the air, yet most people still hear a pulse at the difference. The auditory brainstem compares the timing of the two signals to locate sounds, and a small frequency difference shows up there as a beat that exists only in perception. That is why headphones are essential: on speakers you get an ordinary acoustic beat, which is a different thing.
The bands
Binaural beats are usually described by the brainwave band the difference frequency matches. Delta is below 4 Hz and is associated with deep sleep, theta 4 to 8 Hz with drowsiness and meditation, alpha 8 to 13 Hz with relaxed wakefulness, beta 13 to 30 Hz with alert focus, and gamma above 30 Hz with intense attention. The idea behind entrainment is that listening to a beat in a band nudges the brain towards it. The research is mixed: some studies find small effects on mood or attention, others find none beyond what any calm sound provides. Treat it as a pleasant focus or wind-down sound rather than a treatment.
Choosing a carrier
The carrier is the pitch you actually hear, and it matters more for comfort than effect. Binaural beats are perceived most strongly with carriers below about 1000 Hz, and most people find 200 to 400 Hz easy to sit with for a long session. Lower carriers feel warmer and hide the tone under music better; higher ones are clearer but fatiguing. The beat is kept symmetric around the carrier so changing the beat does not shift the overall pitch.
Pink noise and volume
Pink noise falls off with frequency the way most natural sound does, so it masks the room without hissing. A little of it under the tone makes long sessions less tiring and covers the moment the ear starts to fixate on the pure sine. Keep the volume low: a binaural beat works at any level above audibility, and half an hour of a loud tone in headphones is worse for your ears than any benefit the beat could bring.
FAQ
Do binaural beats really work?
They reliably produce the perceived pulse, which is a well-documented auditory effect. The claims about sleep, focus or anxiety are less settled; controlled studies show small and inconsistent results. Many people find them relaxing, which is reason enough to use them, but do not expect them to replace sleep or medication.
Why do I need headphones?
Because the effect depends on each ear hearing only its own tone. Through speakers the two tones mix in the air and you hear a monaural beat, an ordinary volume wobble that anyone in the room can hear. Earbuds are fine; over-ear headphones with good isolation are best.
What frequency should I use?
For winding down, a theta beat around 6 Hz on a 200 Hz carrier is the common starting point; for reading or working, an alpha or low beta beat of 10 to 15 Hz. Very slow delta beats below 2 Hz are hard to perceive as a beat at all. Try a few and keep whatever you find easiest to ignore.
Can I leave it running while I sleep?
Yes, the tone runs until you stop it or close the tab, and the elapsed counter shows how long it has been playing. Turn the volume right down first, and prefer a low carrier with some pink noise so the sound stays unobtrusive through the night. Some browsers pause audio on a locked phone; a laptop will keep playing.
Is this safe?
At low volume, for people without a seizure disorder, a steady tone is as safe as any other sound. If you have epilepsy or are sensitive to rhythmic stimulation, or if the beat makes you uncomfortable or dizzy, stop. Do not use it while driving or doing anything that needs full attention.
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