Last night I listened to a Delta wave recording for 30mins. After 40 mins I started to feel a sedating affect in my head and fell asleep for about 2 hours. Has anyone else tried using the Delta wave? Apparently it helps to reduce cortisol.
Have you heard of binaural beats? It’s a technique that’s been around for a while, but recently is getting a lot of attention for its ability to lower stress and improve sleep, as well as to improve your cognitive performance.
You’ve heard me talk before about how sound can make a difference to sleep. Patients often tell me that they fall asleep to relaxing music, they seem to find it really helps them let go of active thoughts and quiet their mind—which, like yours probably does, tends to race from one thing to the next all day long (aka I can’t turn off my brain syndrome).
Binaural beats are a fascinating and exciting technology that harnesses the brain’s responsiveness to sound in order to move you into a state of deep relaxation, relieve anxiety, and help you sleep better.
What are binaural beats?
Sounds like a new music genre, right? Not exactly. Binaural beats are a technique of combining two slightly different sound frequencies to create the perception of a single new frequency tone.
The theory is that when exposed to two different frequencies at the same time, one in each ear, what the brain actually perceives a single tone that is the difference between the two separate frequencies. Your brain, in a sense, “tunes” to this new frequency.
You listen to binaural beats using headphones. In each ear, you receive sound at a slightly different frequency (often accompanied by some relaxing background sounds). If your left ear receives a 300-hertz tone and your right ear receives a 280-hertz tone, your brain will process and absorb a 10-hertz tone. That’s a very low-frequency soundwave—one you can’t actually hear. But you don’t need to hear the sound for your brain to be affected by it.
Why is exposure to these soundwaves helpful to sleep and relaxation? Science shows that exposure to binaural beats can create changes in the brain’s degree of arousal. Listening to these sounds that create a low-frequency tone, research indicates, triggers a slow-down to brainwave activity—and that may help you relax, lower your anxiety, and can make it easier for you to fall asleep and sleep more soundly.
How brain waves work
To understand how binaural beats may help relaxation, mood, mental performance, and sleep, you need to know a little bit about brain waves and what they indicate about our state of consciousness, emotion, and mental activity.
Brainwaves are created from the pulses of electrical activity our neurons exhibit as they communicate with each other. Our thoughts, feelings, and actions are all expressed through this constant neural communication—so our brainwaves are associated with how we feel and what we can do at any given moment.
For the purpose of this discussion, we’ll talk about four major types of brainwaves:
Beta: These brainwaves are associated with high levels of alertness and arousal. When beta brainwave patterns dominate, we’re primed to focus and concentrate, to make decisions and think analytically. When you’re analyzing an issue at work, you’re probably in a beta-dominant state. Beta waves are fast, with a higher frequency (between 15-40 hertz). At the higher levels of this range, beta waves are associated with anxiety.
Alpha: Alpha brainwave patterns are associated with a state of wakeful relaxation. Slower and lower in frequency (between 9-14 hertz), alpha waves are dominant when we’re calm and relaxed, but still alert. Alpha waves are associated with states of meditation (your yoga class probably puts you in an alpha state), and also with our ability to be creative.
Theta: This brainwave pattern is associated with deep relaxation and with some stages of sleep, including the lighter stages of non-REM (NREM) sleep. REM sleep itself is mostly composed of beta wave and other activity that’s similar to an alert, waking brain. Deep meditation produces theta waves, which are slower and lower frequency (between 5-8 hertz) than Alpha waves. That murky barrier between sleep and wakefulness, when you’re drifting in and out of sleep, and your thoughts feel dreamlike and difficult to remember? That’s a theta-dominant state of consciousness.
Delta: If you’ve been reading this blog for a while, you’ve heard me talk about slow-wave, delta sleep. Delta waves are slow, low-frequency brainwaves (between 1.5-4 hertz) that are the dominant brainwave pattern of deep (stage 3 and 4), NREM sleep.
As you can see, the faster (and higher frequency) the brainwave pattern, the greater your state of arousal. The slower and lower frequency brainwaves are, the deeper your state of relaxation—or sleep.
Sound affects brainwaves
What scientists have observed for decades is that exposure to sound waves can affect brainwave patterns. In a process called entrainment (aka “tuning the brain”), when exposed to sound waves at certain frequencies, brainwave patterns adjust to align with those frequencies.
This is one way scientists think binaural beats work—by exposing the brain to beats that create low-frequency tones in the brain, these sound waves create shifts in brainwaves themselves, generating slower frequency brainwaves that promote deeper states of relaxation.
How binaural beats might improve sleep
Your brainwave activity during sleep is largely distinct from your brain activity when you’re awake. (REM sleep is one exception to this—during REM, your brain is active in ways very much like when you’re awake.) During non-REM sleep, the slower, lower frequency theta and delta waves dominate, compared to the alpha and beta waves that are prominent when you’re alert and active.
A therapy that slows brainwave activity, helping to produce low-frequency waves, is likely to aid relaxation and sleep. But it’s not only lowering brainwave frequency that binaural beats may offer to sleep and relaxation. A small study (19 people) has found that exposure to binaural beats is associated with changes to three hormones important to sleep and well being:
DHEA functions as a kind of master hormone, helping to produce other hormones in the body on an as-needed basis. DHEA is critical to immune function and disease protection. Particularly significant for sleep is that DHEA works to suppress cortisol, a hormone that stimulates alertness and provokes stress at elevated levels.
The study found that 68 percent of participants had increases to DHEA after using binaural beats.
Cortisol is an arousal hormone, stimulating alertness and attention. Cortisol levels rise and fall in connection to circadian rhythms—cortisol levels rise to their peak levels first thing in the morning, just in time for you to be active for the day. Too-high cortisol levels are associated with insomnia, as well as more time spent in light sleep, rather than deep sleep.
The study found that 70 percent of participants experienced a reduction in cortisol after exposure to binaural beats.
Melatonin promotes and regulates sleep. Melatonin levels rise dramatically in the evening, and the hormone works to relax your body and mind, preparing you to fall asleep.
The study found 73 percent of participants had higher levels of melatonin after using binaural beats. The average increase was more than 97 percent.
In addition to potentially boosting sleep-promoting hormones, binaural beats may also reduce our perceptions of pain. A 2017 study found binaural beats used in combination with visual stimulation led to reductions in patients’ perception of acute pain. Other recent research showed binaural beats helped improve pain perception in patients with chronic pain.
This is good news on its own—and also promising news for sleep. Pain often interferes with sleep (and poor sleep can make pain worse). Reducing pain is one effective way to improve sleep.
Binaural beats for anxiety reduction
There’s a growing body of research suggesting that binaural beats can reduce different forms of anxiety, from mild to chronic. One especially interesting study looked at the effects of binaural beats on anxiety among patients preparing to undergo surgery—a life circumstance that is pretty anxiety provoking for most anyone. Over a period of six months, patients spent 30 minutes on the day of their surgery listening to binaural beats. Compared to patients who listened to a soundtrack that did not include binaural beats—and patients who received no “beats” therapy at all—the binaural beat listeners experienced significantly greater reductions in their anxiety levels.
Another study looked at whether binaural beats help anxiety in patients preparing for cataract surgery, and found binaural beats led to reduced anxiety levels and lower blood pressure levels, before surgery.
Scientists are also looking at how binaural beats affect cognitive abilities, and whether this is a therapy that can be used to enhance cognitive functions such as learning, memory, focus, and creativity. Here’s some of what we know:
Research suggests that binaural beats can help working memory and long-term memory, and also strengthen connections among networks within the brain.
Attention may also be improved by using binaural beats, research shows.
Studies have shown binaural beats may affect levels of dopamine, a hormone that plays a broad role in cognition and a particular role in creative thinking. This has scientists examining the possibility that binaural beats can be used to stimulate creativity. (If you’re looking to be more creative and innovative in your thinking, keep in mind that sleep itself is a powerful tool!)
A few important notes here:
Some studies have found that binaural beats can affect cognitive function positively or negatively, depending on the specific frequency that’s generated. For example, a study of long-term memory found that beta-frequency binaural beats improved memory, while theta-frequency binaural beats interfered with memory. This is something for scientists to continue to examine closely. For people who use binaural beats, it’s important to understand that different frequencies will produce different effects.
When studying the impact of binaural beats on cognition, researchers often find that individual differences matter in whether the therapy delivers a benefit. Right now, it looks as though at least some the benefits of binaural beats may work for some people, and not for others.
Research into binaural beats is growing—but it’s still early. We’ve got a lot more to learn about how this technique affects brain function and ways we might use it most effectively. That goes for cognitive enhancement, as well as for sleep, relaxation, and mood.
There is a lot to like about this technology as a potential treatment for sleep problems. It’s low impact and non-invasive, it doesn’t rely on chemical drugs, it’s inexpensive and for most people likely easy to adopt and maintain. In this way, it’s similar to the other behavioral therapies for sleep that I like so much, including meditation and relaxation techniques, and other mind-body therapies.
Michael J. Breus, Ph.D., DABSM
The Sleep Doctor™