Binaural Beats

About 10 years ago a friend asked me about binaural beats. I had to admit at the time that I was oblivious, and had never heard of them. He proceeded to describe a fun audio effect, one that only works through a pair of headphones. If you play an audio tone (frequency) in each ear, and make the tone in each ear a little different, the difference between the frequencies of these two tones - their interference pattern - can be heard as a third audio tone that sounds like it's originating from somewhere between your ears. So, if you play a 550Hz tone in your left ear, and a 500Hz tone in your right ear, you will also “hear” a 50Hz tone between your ears: 550 - 500 = 50.

This seemed plausible to me, so why was my friend bringing me this topic, as something of skeptical interest. Well, it turns out that, as seems to be the case with many interesting discoveries, some people had taken this cool phenomenon and started selling it, promising people that it could do magical things, like helping people to sleep, improving their mood, and treating health conditions. Some of these audio files were being sold for up to US$1,000!

Here's an example that took me about 10 seconds to find on YouTube - a binaural beat that will apparently treat allergies:

And here's another that can apparently heal tinnitus:

A browse of the YouTube results for “binaural beats treatment” brought up audio that supposedly treats not just allergies and tinnitus, but also:

  • Nausea
  • Stomach issues
  • Nerve damage
  • Toothache
  • Dementia
  • Dyslexia
  • Alzheimer's
  • Hangovers
  • Pain
  • Premature ejaculation
  • ADHD
  • ADD
  • Hair Loss
  • Sinus issues
  • Eye bags
  • Migraines
  • Depression
  • Bronchitis
  • Asthma

There's a lot more, but you get the idea!

There's no lack of supposedly reputable websites that will tell you about the benefits of binaural beats, usually with some kind of disclaimer at the end that they might not actually do anything, and there's no real evidence of efficacy. Here are a few:

_How do you relax before you fall asleep? Maybe you follow a guided meditation, or perhaps you listen to a podcast or peaceful music. Another possible auditory strategy is listening to binaural beats as you drift off to sleep.

Binaural beats aren't a music genre. They are an auditory phenomenon created by your brain in response to hearing specific tones in each ear. Early research of the experimental treatment indicates that listening to binaural beats can reduce feelings of anxiety and improve your ability to fall asleep…

How Do Binaural Beats Work?

When each ear hears a tone at a slightly different frequency, your brain tries to compensate by creating the perception of a third sound. This creation of a third sound is caused by the same part of the brain that helps you determine the location of a sound. To hear the binaural beat, you must have sound coming in each ear. If you take out one of your earbuds, you'll no longer hear the binaural beat.

When binaural beats are sustained over a period of time, they can synchronize with your brain waves. As a result, binaural beats can alter your brain wave activity as well as your levels of arousal._

_[https://www.sleepfoundation.org/noise-and-sleep/binaural-beats](https://www.sleepfoundation.org/noise-and-sleep/binaural-beats)_

_Listening to audio with binaural beats may benefit your mental health and promote creativity and focus…

While most studies on the effects of binaural beats have been small, there are several that provide evidence that this auditory illusion does indeed have health benefits, especially related to anxiety, mood, and performance…

With several human studies to back up the health claims, binaural beats appear to be a potential tool in the fight against anxiety, stress, and negative mental states.

[https://www.healthline.com/health/binaural-beats](https://www.healthline.com/health/binaural-beats)_

_Benefits of binaural beats include:_

- _Increased creativity and cognitive enhancement_
- _Reduced anxiety and improved mood_
- _Helping you enter a meditative state_
- _Improved sleeping habits_
- _Helping to improve focus, attention, and memory retention_

_[https://www.webmd.com/balance/what-are-binaural-beats](https://www.webmd.com/balance/what-are-binaural-beats)_

_Can binaural beats reduce depression?

For those who are suffering from depression, listening to music and/or binaural beats in the frequency range corresponding with alpha, theta, or delta brain waves can provide some relief. Binaural beats music can reduce depression for some people, but most depressed individuals will get better results if they try binaural beats in addition to traditional therapy…

Can binaural beats lower anxiety?

One of the common applications of binaural beats is to reduce anxiety. Several studies found that listening regularly to binaural beats in the delta and theta frequency ranges can be relaxing and ease anxiety symptoms.

[https://www.psychologytoday.com/nz/basics/binaural-beats](https://www.psychologytoday.com/nz/basics/binaural-beats)_

As is often the case, Steven Novella has something to say about this, specifically for the claim of improving memory:

_"Applying my usual criteria to the claim that binaural beats improves memory, I would say the current research is suggestive but not definitive, genuinely warranting further research. Such claims become convincing when they not only replicate, but survive increasingly rigorous methodology, without suffering from the “decline effect” to either clinical or statistical insignificance. I also suspect that there may be a non-specific effect at work here, and at least this would need to be ruled out with careful controls. The question is, if there is a real memory-enhancing effect from specific frequencies of binaural beats, is that due to the increased cross-talk we are seeing in the brain, or is it rather due to a non-specific alerting effect from the stimuli itself? Might any stimulus that is sufficiently annoying or stimulating have the same effect?

This, in my opinion, is the critical question, assuming there is a real effect here at all. Are we really hacking the brain, or is this just a complicated way of producing a non-specific alerting effect."_

https://sciencebasedmedicine.org/the-binaural-beat-goes-on/

The overall idea with binaural beats seems to be that the audio frequencies that are used can adjust the frequencies that our brain uses. Alongside this, is the idea that there are certain brain frequencies that are more beneficial to us, so altering our brains to work at those frequencies can give us benefits. And, thirdly there's an assumption that once our brain has been “improved”, this will presumably in turn allow the brain to help the body to heal - and it seems that different frequencies are meant to tune the brain to help with different health conditions.

An overview of brain waves suggests that there are 5 major wavelengths we see when the brain is operating, and that these are correlated to different functions:

These waves are pulses of electrical activity, at the following frequencies:

  • Gamma, > 35Hz
  • Beta, 12 - 35Hz
  • Alpha, 8 - 12Hz
  • Theta, 4 - 8Hz
  • Delta, 0.5 - 4Hz

Different parts of our brains can be operating at different wavelengths at the same time.

It seems to me, though, that there are a lot of assumptions in this sequence of events. Let's see how many I can spot:

  • Can the frequency of these brain waves actually be altered?
  • If so, can this be done in a reliable way?
  • If so, can this be done in a way that targets only the parts of the brain that may need altering?
  • Can a rhythmic audio beat alter our brain waves?
  • If so, does a beat alter brain waves to match the beat's own frequency?
  • Does this process also work for an illusory binaural beat?
  • Are there preferred, healthy frequencies for each of our brain waves?
  • If so, would inducing these frequencies to match the healthy frequencies cause the desired effects? (this is the causation directionality problem - being happy makes us smile, but forcing someone's mouth into a smile doesn't make them happy)

Having looked at the summaries of some of the preliminary studies for binaural beats, it seems that none of this has really been answered. Of course, as skeptics we know that it's not hard to find a positive result if you're looking for one, but the prior plausibility of this seems very iffy - and the lack of reliable evidence isn't helping matters.

If it ends up that all we need in the future to treat our medical ailments is to don a pair of headphones and listen to some sick beats, I'll be happy to be proven wrong. But, so far, this looks like a case of wishful thinking and the usual snake oil salesmen trying to make a quick buck out of a fun, quirky little piece of science.