Binaural beats and pulsing tones
What Are Binaural Beats? A Plain-English Guide
Two steady tones, one in each ear, and a slow pulse that neither contains. How binaural beats work, why headphones matter, and what the research says so far.
Put on a pair of headphones and picture two sounds. In your left ear, a steady hum at 200 Hz. In your right, another at 206 Hz. Neither one pulses. Yet what you hear is a slow wobble, six times a second, that seems to sit somewhere in the middle of your head. That wobble is a binaural beat, and it isn’t in either tone.
What a beat actually is
The arithmetic is plain. The difference between 200 Hz and 206 Hz is 6 Hz, and that difference is the beat you perceive. It feels like a pulse, though no single sound is pulsing. Think of a shadow: it has no substance of its own, yet it is plainly there.
Two terms do most of the work here:
- Carrier tones. The two tones you actually play. They set the pitch you hear.
- Beat frequency. The difference between the carriers. It sets the speed of the pulse.
A review of the research describes the beat as a perception built by the brain from the two ears’ signals, in the part of the brainstem that compares sound between the ears. Nothing in the air is pulsing. Listen to either ear alone and you would hear only a steady tone.
Why the headphones matter
The trick depends on each ear getting its own tone. Through stereo headphones, that is easy. Through a speaker, both ears hear both tones mixed together, and the beat is no longer a private illusion in your head.
Mixed tones do beat, in the ordinary physical way: two close tones in the same air produce a loudness that rises and falls at the difference rate. That is called a monaural beat, and the beat itself exists in the sound before it reaches you. So a speaker can play a pulsing sound, but it is not a binaural beat.
Pitch matters too. Researchers report that binaural beats are heard only when the carrier tones are fairly low, below about 1,000 Hz. For that reason, carriers in the 100–1,000 Hz range are a sensible place to stay.
Three kinds of pulse
The words binaural, monaural and isochronic get tangled together. A table untangles them quickest.
| Type | What plays | Headphones needed? |
|---|---|---|
| Binaural beat | A different tone in each ear; the beat is perceived | Yes |
| Monaural beat | Two close tones mixed together in both ears; the beat is in the sound itself | No |
| Isochronic tone | One tone switched on and off at a steady rate | No |
An isochronic tone is a single tone that pulses, so it can be played on any speaker. Sometimes it is simply called a pulsing tone.
Why a beat has a name
Beat speeds are often given a name borrowed from brain research, such as delta, theta, alpha and beta. The name is just a label for a number. In OscillaMind, which is coming to iOS and Android, you will see labels like “Theta · 6 Hz” and “Alpha · 10 Hz”: a name and a number that describe the sound you hear. They are not a promise about what the sound does.
Researchers say a binaural beat can be perceived across roughly 1–30 Hz, which is the range listening guides use.
What the research says so far
Here the picture is mixed.
Some analyses combine many small studies. A 2019 meta-analysis in Psychological Research pooled 22 studies and reported a medium-sized average effect across studies of memory, attention, feelings of worry and pain perception. A 2023 meta-analysis of 15 studies, also in Psychological Research, found a medium-sized average effect on memory and attention. Its authors still called the evidence mixed, with conflicting results for theta and beta beats in particular.
Other reviews are more cautious. A 2015 review in Frontiers in Psychiatry found that many studies report contrasting results, and suggested possible reasons: the beat can be hard to perceive, studies use different carrier tones, background noise differs, and listening times and protocols are not always fully reported.
A 2023 systematic review in PLOS ONE asked one narrow question: does the brain’s electrical activity follow the beat? Of 14 studies, five reported results consistent with that idea, eight reported results that contradicted it, and one was mixed. The authors called the picture inconclusive and urged caution with claims of effects.
Put together, that is why OscillaMind labels binaural beats Emerging / Mixed. The label rates the evidence for what people link with the sound, not the sound itself. There are studies, but they are small, varied, and they don’t agree. When the evidence is unclear, we use the lower label.
If you want to try one
Picture a quiet evening, a pair of stereo headphones and the volume turned well down. That is about all it takes. A few simple habits help, whether you listen at a desk or settle in for the evening:
- Use stereo headphones, not a speaker.
- Keep the volume low. There is no need for loud.
- Start with short sessions and stop if you feel uncomfortable.
- Think of it as a sound to explore, not a method. Notice whether you enjoy it.
A carrier in the 100–1,000 Hz range at low volume is a comfortable place to start.
Sound is for listening and routines, not medical care. If you have a health concern, talk to a doctor.
Sources
- Ingendoh, Posny and Heine (2023), systematic review of binaural beat studies using brain recordings, PLOS ONE. https://pmc.ncbi.nlm.nih.gov/articles/PMC10198548/
- Chaieb, Wilpert, Reber and Fell (2015), review of auditory beat stimulation, cognition and mood, Frontiers in Psychiatry. https://pmc.ncbi.nlm.nih.gov/articles/PMC4428073
- Garcia-Argibay, Santed and Reales (2019), meta-analysis of binaural beat studies (22 studies), Psychological Research. https://doi.org/10.1007/s00426-018-1066-8
- Basu and Banerjee (2023), meta-analysis and systematic review of binaural beats, memory and attention (15 studies), Psychological Research. https://doi.org/10.1007/s00426-022-01706-7
- Beat (acoustics), Wikipedia. https://en.wikipedia.org/wiki/Beat_(acoustics)
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