Glazik Prod SleepHeart Sutra meditationTheta waves · 30 minutes
Short answer: binaural beats are a real perception, but the evidence that they reliably change brain waves is mixed, and the evidence for sleep is thin. A 2023 review of 14 brain-recording studies found 5 results for, 8 against and 1 mixed. They are safe for most people at a low volume, and they need headphones.
What are binaural beats?
Play a 200 Hz tone in your left ear and a 206 Hz tone in your right ear. Neither tone pulses, yet you hear a slow wobble, six times per second. That wobble exists in no headphone: your brain creates it by comparing the two ears. This effect was described by the biophysicist Gerald Oster in Scientific American in 1973.
The difference between the two tones is named after the brain wave band it matches: delta for very slow beats, theta, alpha, beta, then gamma for the fastest, such as 40 Hz.
Do they change your brain waves?
This is the big promise, called entrainment: if you hear a 6 Hz beat, your brain is supposed to follow it at 6 Hz. In 2023, researchers reviewed 14 studies that measured brain activity during binaural beats. Five supported the idea, eight contradicted it and one was mixed. The studies used very different sounds, durations and measurements, so no firm conclusion was possible.
What studies found on anxiety, pain and focus
A 2019 meta-analysis pooled 35 results from published studies and found a medium, consistent effect of binaural beats on anxiety, pain perception and some memory and attention tasks. That is encouraging, and also limited: many of the studies were small, and an effect on how people feel does not prove the brain waves changed. A calm, steady sound can relax you whatever its mechanism.
Do binaural beats help you sleep?
There is no solid meta-analysis on binaural beats and sleep. The few studies are small and their results vary. If a slow delta track helps you wind down, it is a reasonable part of a bedtime routine. Just do not expect it to fix insomnia, and talk to a doctor if poor sleep lasts.
What about 40 Hz and memory?
The 40 Hz excitement comes from research at MIT. In mice bred to develop Alzheimer’s disease, flickering light at 40 Hz in 2016, then 40 Hz sound pulses in 2019, reduced amyloid plaques and improved memory. Those experiments used flicker and sound pulses, not binaural beats, and they were done in mice. In 2023, another team found that 40 Hz light did not drive the natural 40 Hz rhythm in similar mice. Research in people is still ongoing. Our 40 Hz sessions are made for a focused morning mood, nothing more.
Do binaural beats work without headphones?
No. Through speakers, the two tones mix in the air before reaching you, and you hear an ordinary pulsing sound, called a monaural beat. It can still be pleasant, but it is not a binaural beat. For the real effect, each ear needs its own tone, so use headphones or earbuds.
Are binaural beats safe?
For most people, yes, at a low volume. Do not listen while driving or doing anything that needs your full attention. If you have epilepsy or a history of seizures, ask your doctor first. If a sound makes you uncomfortable, stop.
Which frequency for what?
| Band | Range | Brain state where it is measured |
|---|---|---|
| Delta | 0.5 to 4 Hz | Deep sleep |
| Theta | 4 to 8 Hz | Drowsiness, light sleep, meditation |
| Alpha | 8 to 12 Hz | Relaxed and awake, eyes closed |
| Beta | 13 to 30 Hz | Alert, active thinking |
| Gamma | 30 Hz and above | Intense focus and information processing |
These bands describe brain activity measured by EEG. Listening to a beat in a band does not guarantee your brain will follow it.
Prefer plain noise? Try our brown, white and pink noise generator.
No headphones? Try isochronic tones, which work on any speaker.
Listen to a full session
Hawaiian morning meditation40 Hz · 20 minutes
Questions
Do binaural beats actually work?
They work as a sound illusion. Whether they change brain waves is unproven: a 2023 review found 5 studies for, 8 against and 1 mixed. A 2019 meta-analysis found a medium effect on anxiety and pain.
Do binaural beats work without headphones?
No. Through speakers the two tones mix in the air and become an ordinary pulsing sound. Each ear needs its own tone.
Are binaural beats good for sleep?
The evidence is thin and the studies are small. A slow delta track can be part of a relaxing routine, but it will not cure insomnia.
Are binaural beats safe?
For most people, yes, at a low volume. Avoid them while driving, and ask a doctor first if you have epilepsy.
Does 40 Hz prevent Alzheimer’s?
No one knows. The MIT results come from mice and used flicker and sound pulses, not binaural beats. Studies in people are still ongoing.
Sources
Oster G. Auditory beats in the brain. Scientific American, 1973. PubMed
Garcia-Argibay M et al. Efficacy of binaural auditory beats in cognition, anxiety, and pain perception: a meta-analysis. Psychological Research, 2019. PubMed
Ingendoh RM et al. Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity. PLOS ONE, 2023. PubMed
Iaccarino HF et al. Gamma frequency entrainment attenuates amyloid load and modifies microglia. Nature, 2016. PubMed
Martorell AJ et al. Multi-sensory gamma stimulation ameliorates Alzheimer’s-associated pathology and improves cognition. Cell, 2019. PubMed
Soula M et al. Forty-hertz light stimulation does not entrain native gamma oscillations in Alzheimer’s disease model mice. Nature Neuroscience, 2023. PubMed
This page is for general information and is not medical advice. If you have ongoing sleep or health problems, talk to a doctor.