Binaural beats generator: for sleep, calm and focus

What are binaural beats, in plain words

Picture two strings tuned almost the same. When they sound together, the sound starts to swell and fade slowly. That swelling is called a beat, and its rate equals the difference between the two frequencies.

A binaural beat is the same thing, except that it is born in the head, not in the air. One tone goes to the left ear, a slightly different one to the right. Each ear hears only its own tone, the brainstem combines them, and you hear a third sound: a slow pulse that is not actually present in either earphone.

The phenomenon was described in 1839 by the German physicist Heinrich Wilhelm Dove and became widely known after the biophysicist Gerald Oster's article in Scientific American in 1973. Binaural means “with two ears”.

How the binaural beats generator works

The generator makes the sound in your browser, so there is nothing to download and the frequencies are exact. You choose two things: the carrier tone and the beat frequency. With a 200 Hz carrier and a 6 Hz beat, the left ear hears 200 Hz, the right ear 206 Hz, and the brain hears a 6 Hz pulse.

The carrier only decides how the sound feels: lower is softer, higher is brighter. The beat frequency is what matters for the effect, so pick a carrier you find pleasant.

The isochronic tones mode works differently: one tone is switched on and off at the chosen rate. The pulse is then in the sound itself, so no headphones are needed.

• Both tones must be below 1000 Hz, otherwise the brain no longer combines them.
• The beat is clearly heard when the difference is roughly 1 to 30 Hz.
• Set the volume so the tone is barely audible. A louder sound does not make the effect stronger.

Which frequency to choose: delta, theta, alpha, beta or gamma

The electrical activity of the brain is divided into five frequency bands, and each is seen more often in a certain state. Binaural beats are named after the same bands: you choose the beat that matches the state you are after.

The borders between the bands are not strict, and people differ. If 10 Hz calms you and 6 Hz makes you sleepy, that is normal. Try a few frequencies and keep the one after which you feel the way you wanted.

Binaural beats benefits: what the research shows

The strongest evidence is a 2019 meta-analysis in which Spanish researchers pooled the results of 22 studies. The overall effect of binaural beats on memory, attention, anxiety and pain perception was medium (g = 0.45), significant and consistent across studies. The authors concluded that binaural-beat exposure is an effective way to affect cognition and to reduce anxiety and the perception of pain, without prior training.

The same analysis showed three practical things. First, longer listening works better. Second, listening before the task, or before and during it, gives better results than during the task only. Third, the beat does not have to be hidden under noise or music: a plain tone works just as well.

An anxiety study worth knowing: in a UK hospital, patients waiting for day surgery were randomly split into three groups. Anxiety fell by 26.3% in those who listened to a recording with binaural beats, by 11.1% in those who heard the same recording without them, and by 3.8% in those who listened to nothing.

• Less anxiety and tension before a stressful event.
• Better attention and memory when you listen before the task.
• Weaker perception of pain.
• Better self-rated sleep quality.

It is fair to say what studies have not settled yet. In a 2023 review of 14 studies that measured brain waves themselves, five showed that brain activity follows the beat, eight did not, and one gave mixed results. In other words, the effect on how people feel and perform is measured better than the mechanism behind it.

Binaural beats for sleep

For sleep people use delta beats, most often 2 to 3 Hz. In a pilot study by Iranian researchers, 20 students listened to a delta beat for a week: they fell asleep faster, woke less often at night, slept longer and rated their sleep and their mornings better. Anxiety and anger decreased as well.

In a study at the German Sport University, 15 young football players slept with 2–8 Hz binaural beats for eight weeks. Their ratings of sleep quality, awakening and motivation improved, while a control group that slept without the sound showed no change.

Not every study is that clear-cut. In a double-blind trial in South Korea, 43 people with mild insomnia listened to music with or without theta beats before bed for two weeks. Sleep improved in both groups, and the difference between them was not statistically significant. So treat binaural beats as one tool next to darkness, a cool room and a regular bedtime, not as a replacement for them.

• Choose the delta preset (2 Hz) and a 30-minute timer; the sound fades out by itself.
• Listen lying down, with your eyes closed.
• If headphones get in the way, use isochronic tones through a speaker or sleep headphones.

Binaural beats for focus and studying: beta and 40 Hz

For attention people use beta (14–30 Hz) and gamma (40 Hz) beats. In a Leiden University study, people who listened to a 40 Hz beat focused on detail better than those who heard a constant tone. In a memory study, participants recalled more words after a 20 Hz beta beat and fewer after a 5 Hz theta beat than the control group.

Hence a practical rule: slow beats do not suit the time before study and work. Keep theta and delta for the evening, and listen to a beta or gamma beat for 15 minutes before you start.

40 Hz is often mentioned together with research at the Massachusetts Institute of Technology. That work uses a different method, a light flickering and a sound clicking at 40 Hz, not binaural beats, so those results cannot be applied to binaural beats directly.

Binaural beats for anxiety and meditation: alpha and theta

An alpha beat (8–14 Hz) matches the state of sitting with your eyes closed, calm but awake. It suits the end of a working day, the minutes before an important conversation, or the moment when thoughts go round in circles.

A theta beat (4–8 Hz) is slower and is associated with deep meditation and the state between waking and sleep. It helps beginners in meditation by giving attention something to rest on: you listen to the pulse instead of fighting your thoughts.

Listen sitting or lying down for 15 to 20 minutes. Breathe slowly: in for a count of four, out for a count of six.

Isochronic tones vs binaural beats

A binaural beat is made by the brain out of two tones, so it is gentle and needs headphones. An isochronic tone pulses by itself: sound, no sound. The pulse is sharper and can be heard through a speaker.

In a study by researchers in Canada and France, a sound whose pulse is in the signal itself entrained the activity of the cortex more strongly than a binaural beat. So if you can barely hear the binaural beat, or it does nothing for you, try the isochronic mode.

Are binaural beats dangerous

In studies with healthy people and with patients before surgery, no serious side effects have been described. It is a quiet sound that you listen to for as long as you like.

A few things are worth knowing.

• Volume. Hearing is harmed by loudness and duration, not by frequency. The World Health Organization considers sound of no more than 80 dB safe for up to 40 hours a week. For binaural beats a barely audible level is enough.
• Epilepsy. Rhythmic stimuli can trigger a seizure in some people with epilepsy, so talk to your doctor before listening.
• Driving. Delta, theta and alpha beats calm you down and make you sleepy. Do not listen while driving or operating machinery.
• Unpleasant sensations. If you get a headache, feel dizzy or uneasy, switch the sound off. Next time choose another frequency and a lower volume.

Sound is only one tool

Binaural beats work best when they are not alone. Sleep also depends on the light you get in the morning and in the evening, a calm nervous system also depends on breathing, and focus also depends on how you slept.

Use the generator as part of a routine: a beta or gamma beat before work, an alpha beat after it, a delta beat in bed. Keep the same time every day for a week and note how you feel; that tells you more than any single session.