The short version
Put on headphones. Your left ear hears a steady tone at 400 Hz and your right ear hears one at 410 Hz. Neither tone pulses on its own, but together your brain perceives a soft "wah-wah" at 10 beats per second: the 10 Hz difference between them. That perceived pulse is the binaural beat.
People use binaural beats as background sound to help them focus, relax, meditate or fall asleep. The idea is that a steady rhythm at a particular rate can nudge your mind toward a matching state.
How they work
Each binaural beat has two parts:
- The carrier is the tone you actually hear, usually between 100 and 500 Hz. Lower carriers sound warmer; higher ones sound brighter.
- The beat is the difference between the two ears, usually between 1 and 40 Hz. This is the rhythm your brain picks up, and it's what the presets are named after.
The beat is created inside your auditory system, in the brainstem, where signals from both ears meet. That's why the effect is called binaural, meaning "two ears".
Why you need headphones
If you play the two tones through speakers, they mix in the air before they reach you, and each ear hears both. You'll hear an ordinary acoustic beat, not a binaural one. Stereo headphones or earbuds keep the tones separate, so each ear gets only its own tone. Any reasonable pair works. They don't need to be expensive.
Frequency bands and what they're used for
Beat frequencies are usually grouped into the same bands used to describe brainwaves:
- Delta (0.5–4 Hz): deep sleep and rest.
- Theta (4–8 Hz): meditation, drowsiness, daydreaming and creativity.
- Alpha (8–13 Hz): calm, relaxed alertness. A good first frequency to try.
- Beta (13–30 Hz): active thinking, focus and alertness.
- Gamma (30 Hz and up): concentration and attention. 40 Hz is the most popular.
What the research says
The honest answer is: promising but mixed. A 2019 meta-analysis by Garcia-Argibay and colleagues, which pooled the results of many earlier studies, found small to moderate effects of binaural beats on memory, attention, anxiety and pain perception. The results varied a lot between studies, and many of the studies were small.
In practice, binaural beats work well for some people and do little for others. Because they're free and low-risk, the easiest way to find out is to try them for a few sessions and see how you feel.
How to try them
- Put on stereo headphones and set your volume low. The beat works at a quiet level.
- Choose a goal: focus, relaxation, meditation or sleep.
- Play a matching preset for 15 to 30 minutes while you work, rest or lie down.
- Try it a few times before deciding. Most people need a session or two to get used to the sound.
Binaural, monaural and isochronic tones
You may also come across monaural beats, where the two tones are mixed before they reach your ears, and isochronic tones, a single tone switched on and off at a steady rate. Both work through speakers. Binaural beats are gentler and smoother to listen to, but they need headphones.
Are binaural beats safe?
For most people, yes. Keep the volume comfortable, and don't use them while driving or doing anything that needs your full attention. If you have epilepsy, a seizure disorder or another neurological condition, check with a doctor first. Stop if you get a headache or feel uncomfortable.
Common questions
How long should I listen to binaural beats?
Fifteen to thirty minutes is a good starting point. For focus or study you can listen for a full work session, and for sleep, set a 30 to 45 minute timer so the sound stops on its own.
Can I listen to binaural beats with music?
You can, but busy music, especially with lyrics, tends to drown out the beat. A low level of pink or brown noise is a better companion, because it masks distractions without competing with the tone.
What carrier frequency should I use?
Anything from about 100 to 500 Hz works. The beat is easiest to perceive on carriers below about 1000 Hz. Lower carriers sound warmer and suit relaxation and sleep, and slightly higher ones sound brighter for daytime focus.
Do I need to concentrate on the sound?
No. Binaural beats work as background sound. Most people stop consciously noticing the tone after a few minutes.