Can you slip into a more relaxed state and sharpen your focus by simply listening to a couple of slightly different tones? That’s the idea behind binaural beats, an auditory phenomenon that’s increasingly getting headlines as a cure for procrastination and everyday stress.
The idea of binaural beats is hardly new. Heinrich Wilhelm Dove, a physicist and meteorologist, first recorded the phenomenon in 1839. But, nearly 190 years later, scientists are still exploring what they are and what they can and can’t do, Bopanna Ballachanda, past president of the American Academy of Audiology and an expert in auditory neuroscience, tells Popular Science. Here’s what binaural beats are, and what the science says about their effectiveness.
What are binaural beats?
Sounds are measured by their frequency in hertz, which counts how many times a sound wave vibrates per second. Low tones have low frequencies and a lower hertz value, while high tones have high frequencies and a higher hertz value.
A binaural beat occurs when two tones with different frequencies are played in each ear, producing a third phantom tone, or binaural beat. The frequency of that third beat is the gap in the frequencies between the two separate tones.
So, if you play a 400-hertz tone in the right ear and a 404-hertz tone in the left ear, the brain perceives an imaginary binaural beat of four hertz, Ballachanda says. “That difference in the frequency of sound creates an image in the brain as a beat, the basis of the binaural beats.”
In short, binaural beats are auditory illusions your brain creates when it hears different tones in each ear. But be sure you’re wearing headphones (perhaps these or these), or else you won’t hear that phantom binaural beat.
Binaural beats are when two different frequencies are played in each ear, prompting your brain to create a third illusionary tone. Credit: The Anxiety Guy
Why do we hear a binaural beat?
When a brain creates an imaginary binaural beat, some researchers believe it could lead to “brain entrainment.” The brainwave entrainment hypothesis, as a 2023 systematic review explains, suggests that when the brain is exposed to a binaural beat, the brain’s electrical activity syncs up to that frequency.
Specific frequencies have been connected to different emotions or cognitive abilities. For example, researchers have found delta brainwaves, measured at 0.5 to four hertz, are linked to deep sleep and pain relief. Theta waves, measured at four to seven hertz, can help with deep relaxation. Alpha waves, measured at eight to 12 hertz, are associated with learning.
Binaural beats can be perceived from about one to 30 hertz, the systematic review says. So syncing up our brains to a binaural beat that generates a relaxing frequency could allow us to manipulate our brains to chill out a bit. But the jury is still out on whether binaural beats trigger brainwave entrainment, according to the review. Among the 14 studies reviewed, five supported the idea, eight contradicted it, and one ended with mixed results.
What does science say about binaural beats?
The science also is still very much evolving on the actual impact of binaural beats to our mood and cognitive abilities, Ballachanda says.
Some studies show promising results. A 2018 meta-analysis of 22 studies, for example, found that the beats can boost cognition, including memory and attention, and reduce anxiety and pain. The effectiveness, researchers found, depends on the frequency used, the time under exposure and the moment when the exposure took place.
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In a 2020 study, participants who combined psychiatric treatment with binaural beat meditation had larger reductions in anxiety compared to those who used only binaural beats or psychiatric care.
Then in a 2025 study, 80 undergraduate students listened to both control sounds and binaural beats. The study found that specific binaural beats with a low tone and white nose improved general attention but didn’t stop focus from eventually fading. The results confirmed brain entrainment, but it varied with the binaural beat and background noise.
But not every study shows positive effects. One 2023 study of 1,000 people found that listening to binaural beats at home while taking a test reduced their performance, while silence or listening to other sounds had no impact.
If you want to give binaural beats a try, there’s no harm, Ballachanda says, as long as you don’t turn the volume up too loud. “Beats do not cause damage by itself,” he says.
So, if you’re eager to unwind or focus on that big assignment, it could be worth giving binaural beats a shot. Online options on YouTube and elsewhere make it easy to tune in and, possibly, reframe your state of mind.
This story is part of Popular Science’s Ask Us Anything series, where we answer your most outlandish, mind-burning questions, from the ordinary to the off-the-wall. Have something you’ve always wanted to know? Ask us.
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