What are binaural beats and can they really help you sleep?
People have been using external substances to help induce sleep for many, many years – teas and supplements, herbs and incense, meditations and rituals, even alcohol (though it doesn’t work very well). But these additions don’t always have a measurable effect on sleep quality.
In more recent years, some scientists have studied the possibility of using the brain’s responsiveness to sound itself to help induce a state of sleep. In theory, this method could help everyone, including those with chronic sleep difficulties, find more restful sleep more reliably.
Researchers have found that producing different kinds of binaural beats can cause study participants to report different effects.
But what are binaural beats? How are they supposed to work? Here’s the lowdown:
Step 1: What are brainwaves?
As your brain functions, it produces electricity. However, that electricity is NOT generated entirely randomly; scientists have found that the electricity generated by someone’s brain is generated in patterns.
These patterns are called “neural oscillations,” also known as brainwaves. These waves can be measured in Hertz (cycles per second) and can have frequencies between 0.5 Hz and 50 Hz.
Scientists can measure some brain activity by using an electroencephalogram (EEG), which measures electrical patterns occurring on the surface of the brain by recording electrical activity on the scalp. Research has shown that, when your brain does different tasks (concentrating, sleeping, meditating, etc.), the patterns of your brain activity change… somewhat reliably.
Five general patterns of oscillation have been discovered so far, and their full roles in brain function aren’t yet fully understood. Certain patterns have, however, become associated with different states of brain activity. The Sleep Foundation makes the following associations in their article about binaural beats:
- Delta pattern (0.5-4 Hz), as the slowest rate of activity, is associated with deeper stages of sleep and dreaming.
- Theta pattern (4-8 Hz) is the pattern for the lightest stages of sleep, associated with drowsiness and meditation.
- Alpha pattern (8-13 Hz) indicates a relaxed and restful mind.
- Beta pattern (13-30 Hz) indicates a mind that is active and alert, but can also be associated with anxiety.
- Gamma pattern (30-50 Hz), as the highest-frequency activity, is associated with alertness, concentration, and problem solving.
Keep all that context in mind – now, we’ll talk about binaural beats.
Step 2: What are binaural beats?
We also know that our brains are incredibly responsive to sound, from the way we process music as infants to being able to pick our own name out of a loud, crowded room.
Binaural beats aren’t some new kind of club music or drumming rhythm. It’s actually a technique produced with headphones and two sounds at slightly different frequencies.
When listening to a binaural beat through headphones, a slightly different tone is played in each ear. The brain, generally, doesn’t like when things don’t quite line up. As such, the brain responds to the difference between the sounds by creating a third beat at the difference between the two tones. This third tone is called the binaural beat.
Example: If you listen to a beat at 200 Hz in one ear, and 225 Hz in another, the binaural beat your brain creates is at 25 Hz.
This binaural beat is only created when the headphones are both in your ears and playing the different tones. If one of the tones is lost (whether because the headphone dies or one earphone is taken out), the binaural beat is no longer created by your brain.
So, why does this matter? Because of how the binaural beat can interact with your brain waves.
Step 3: How do they interact?
Remember how different brain waves have certain frequencies, ranging from 0.5 Hz to 50 Hz?
Well. Scientists theorize that, by forcing the brain to create a frequency in the 0.5 to 50 Hz range, your brain activity will synchronize with that frequency. Therefore, you might find it easier to do things that are associated with that frequency. Like, sleep. Or focus. Or problem-solve.
For our purposes, we’ll stick with theta and delta frequencies (since those are the ones associated with sleep). Ideally, by listening to a binaural beat between the frequencies of 0.5 Hz and 4 Hz, you’d induce deep sleep. If you’re having trouble falling asleep, by listening to a theta-frequency binaural beat, you could induce a state of drowsiness that could help you fall asleep.
The Sleep Foundation cites a study through the National Institute of Health that exposed sleeping participants to binaural beats at a delta frequency of 3 Hz. The study found that “these beats induced delta activity in the brain. As a result, the use of binaural beats lengthened stage three sleep. Stage three sleep is deep sleep and important for feeling refreshed in the morning.”
So, does it work?
Can binaural beats help you sleep? Preliminary research says, “yes,” but that research has its critics and limitations. There’s not enough evidence about its long-term effects either, since the technology is quite new.
For now, it’s safe to assume that binaural beats are effective as part of creating a sleep routine, as any “white noise” playlist or other sleep ritual. Anything more than that is speculation – but this is an exciting technology to consider when thinking about the future of sleep and treatment of sleep-related disorders.