Sit in a quiet room with a pair of headphones, play a pure 200Hz tone into your left ear and a 210Hz tone into your right, and something curious happens. Neither ear is receiving anything but a smooth, unbroken tone — yet somewhere between them, a slow pulse appears. Ten gentle beats every second, as vivid to your ears as a drum, produced by nothing more than two steady sounds that refuse to quite agree with each other.

That pulse is a beat frequency, and it sits at the heart of two of the most talked-about techniques in relaxation and meditation audio: binaural beats and monaural beats. The two are often mentioned in the same breath, and often confused, because both begin with the same ingredients — two tones of slightly different frequency. But the way those tones meet, and the way the rhythm reaches you, is quite different. Understanding that difference helps you choose the listening experience that actually suits you.

What are binaural beats?

Binaural beats are built on separation. One tone is played into the left ear and a slightly different tone into the right, and the two never physically mix. Take the classic example: 200Hz in the left ear, 210Hz in the right. What you perceive is not two tones but a single tone that seems to waver ten times per second — a 10Hz beat.

The remarkable part is where that beat happens. There is no 10Hz fluctuation in the sound itself; if you measured the signal at either earcup, you would find a perfectly steady tone. The beat is assembled inside your auditory system, as the brain compares the slightly mismatched signals arriving from each ear and renders their difference as a rhythm. It is, in a sense, a rhythm your brain composes for itself.

This is why headphones are normally required for conventional binaural beats. Play the same two tones through speakers and they blend in the air before reaching you, and the delicate comparison between the ears that the effect depends on is lost. Each ear needs its own private channel.

The effect has a long pedigree. It was first described by the Prussian physicist Heinrich Wilhelm Dove in 1839, and brought to wider scientific attention by Gerald Oster's 1973 paper in Scientific American, which remains one of the most cited references in the field.

What are monaural beats?

Monaural beats take the opposite approach: the two frequencies are combined before they reach you. Mix 200Hz and 210Hz into a single signal and the two waves physically interfere — reinforcing each other, then partially cancelling, ten times every second. The result is a real, measurable fluctuation in loudness: an actual 10Hz pulse travelling in the sound.

Because the beat exists in the signal itself, both ears hear the same pulsing tone, and no separation is needed. Monaural beats work through ordinary speakers as well as headphones, although the experience still depends on your equipment and listening conditions. A small speaker that rolls off low frequencies, or a room full of hard reflections, will soften the effect; a comfortable pair of headphones or a decent speaker in a quiet room will let it breathe.

Binaural beats vs monaural beats

Binaural beatsMonaural beats
How the beat is createdTwo tones kept separate, one per ear; the beat is assembled by the auditory systemTwo tones mixed into one signal; the beat is a physical interference pattern
Headphones requiredYes, for the conventional effectNo
How the rhythm is perceivedA gentle internal wavering, often described as subtle or spaciousAn audible pulsing in the sound itself, usually more pronounced
Listening through speakersThe effect is largely lost as the tones blend in the airWorks, though equipment and room acoustics shape the result
Typical listening characterSoft and immersive, easy to sit inside for long periodsA clearer rhythmic presence, more obviously beating
Potential applicationsMeditation, relaxation and focus sessions where headphones are comfortableSpeaker listening, shared spaces, and listeners who prefer a more tangible rhythm

It is worth saying plainly: neither technique is scientifically proven to be superior. They are two different ways of arriving at a similar destination, and which one feels better is a genuinely personal matter.

Brainwave frequencies and entrainment

You will often see beat frequencies described in the language of brainwaves. The bands most commonly referenced are delta (around 0.5–4Hz, associated with deep sleep), theta (4–8Hz, drowsiness and deep meditation), alpha (8–12Hz, relaxed wakefulness), beta (12–30Hz, alert thinking) and gamma (30Hz and above, heightened processing). We explore the slowest of these in our guide to delta waves and sleep.

These ranges are referenced because of an idea called entrainment — the suggestion that the brain's electrical activity might gently follow a rhythmic stimulus, the way a room full of pendulum clocks can drift into sync. It is an elegant idea, and it is why a 10Hz beat is so often described as an alpha beat.

Two cautions are worth holding on to. First, the frequency of the beat is a property of the sound, not a measurement of your brain; a 10Hz pulse in your headphones is not the same thing as 10Hz activity on an EEG. Second, the research is genuinely mixed. Reviews of auditory beat stimulation, such as Chaieb and colleagues' 2015 overview, describe promising but inconsistent findings, and a 2019 meta-analysis found effects that were real but small and variable. Listening to a 10Hz beat does not guarantee that your brain settles into a 10Hz alpha state — and anyone who promises you otherwise is overstating the science.

Which is better for meditation, relaxation or focus?

The honest answer is: whichever one you actually enjoy listening to. Binaural beats tend to suit people who like a subtle, spacious effect and are happy wearing headphones for a seated or lying-down practice. Monaural beats suit those who prefer a more pronounced, tangible pulse, or who want to listen through speakers — perhaps while stretching, journalling or sharing the space with someone else.

Comfort matters more than theory. A beat you barely notice, at a volume that feels easy, will serve you better than a perfectly chosen frequency listened to through aching ears. What neither method can honestly promise is a medical outcome: these are listening experiences, not treatments, and they work best approached with curiosity rather than expectation.

Can binaural and monaural beats be combined with music?

Very much so, and this is where the craft comes in. Both techniques can be woven into ambient music and evolving soundscapes — the carrier tones tucked inside warm pads, the beat sitting underneath like a slow tide rather than a metronome. Done thoughtfully, the rhythm becomes something you feel more than hear.

Good sound design makes all the difference. The beats should sit at comfortable levels, the frequencies chosen to blend musically rather than clang, and the overall intensity kept gentle — excessive rhythmic stimulation is tiring, not relaxing. This is the approach we take in our own recordings: the frequencies are part of the music, not a machine bolted onto it.

Experience the difference for yourself

The Sound Lab lets you experiment with binaural and monaural beats directly in your browser — adjust the frequencies, switch between the two modes and discover which rhythm feels right to you. It is free to explore, with nothing to install.

Explore the Simply Hypnotic Sound Lab

Final thoughts

Binaural and monaural beats are a lovely reminder that listening is not a passive act. Given two steady tones, your hearing finds a rhythm — sometimes in the air, sometimes in the mind. Which version speaks to you is something only your own ears can answer, and that is rather the point. The most interesting instrument in any listening room is the one between them.

References