I’m going to warn you upfront. This is amazing technology that is definitely in the geek fringe where music meets physics and cognitive neuroscience. There are a lot of pieces to put together here, but if you bear with me, there are some amazing things here.
If you don’t want to read the whole thing but are interested in the results, you can skip to the end.
I first experienced binaural beats when I was not yet 16. I was at a science conference with my dad, and there was a booth where they were selling mind-flight machines. And, you could try them out for free.
The device looked like a walkman that had a pair of goggles and studio headphones to go with it. The goggles had LED lights in them that would flash at a certain frequency. The walkman would play any cassette you put in it with a binaural beats sequence playing underneath it that was synchronized with the flashing LED lights.
At this point, you are probably wondering what binaural beats are, and I will get to that. But first, I want to tell you about my experience in the mind-flight machine.
I put on the headphones, and the goggles, and put in a cassette. It was MC Hammer, and I remember that the song I heard first was “You’ve got to Pray“. I laid back in the chair and relaxed. I then began to lucid dream while I was still kind of awake. I remember seeing 3D geometrics moving, and then I was flying over a canyon.
I was having a heck of a time whirling around the canyon when I heard the voice of a Evelyn, a friend of my dad’s who had attended the conference with us. When I heard her gravelly voice, I was roused from my dream state, and I took off the goggles and looked around for her thinking she must be near.
I spied her across the trade show hall, 50 or more feet away. There were at least 300 people in that room!
Since that moment, I have been fascinated by the technologies of sound.
What Are Binaural Beats?
The easiest way to describe binaural beats is to say that they are a beat frequency that is created by your brain. You probably don’t know what a beat frequency is yet, so I will start at the beginning.
In physics, when 2 frequencies (pitches) are played simultaneously, a 3rd pitch emerges from the interaction of the first 2. In classical music, this 3rd pitch is called a tartini tone. Playing violin, you will hear a tartini tone when you play a double stop perfectly in tune.
There are 2 kinds of combination tones, sum and difference tones. Difference tones are the ones that are of importance here.
If I play two tones, one at 220Hz, and one at 260Hz, you will have a difference tone created at 40Hz. The difference tone is caused by the waves going in and out of sync (phase) with each other so that sometimes they make each other louder, and sometimes they make each other quieter.
When the tones are in phase with each other, the signal is louder. When they are out of phase, they cancel each other out.
The beat that you hear is the sound getting quieter and louder as a result of this effect. The graphics below demonstrate this concept.
You can also hear the effect by listening to this track.
Sound In Your Brain
When you listen to a pitch, that pitch exists in your brain in a very real way. The tone you hear is measurable in your brain waves! The auditory channel into your brain is one of the most direct and least filtered.
And, a large portion of your brain is dedicated to auditory processing. In fact playing music engages your whole brain in a way that little else does.
Now that we know what a beat is, we can explore what it means to have a binaural beat.
Binaural means 2 ears. In essence, a binaural beat is a beat frequency that is created when you listen to the two pitches with one pitch in each ear rather than having them interact in the air.
Wikipedia Defines a binaural beat as:
A binaural beat is an auditory illusion perceived when two different pure-tone sine waves, both with frequencies lower than 1500 Hz, with less than a 40 Hz difference between them, are presented to a listener dichotically (one through each ear).
Now here’s where it gets crazy. When you listen to the pitches with one pitch in each ear (slightly off from each other,) Your brain will create the difference frequency. In order to do this, your brain has to engage both of its hemispheres (right and left brains).
If you play this next track in headphones, you will still hear that difference pitch (40Hz in this case), but this time the interaction of the two tones is happening in your brain.
Frequencies and Brain States
Our brains have underlying frequencies that correspond to different brain states. When we are asleep, our base level frequency is slower, and when we are active, it’s faster. Scientists have given the brain states labels using Greek letters that correspond to the frequencies.
The general chart of brain states looks something like this:
Delta – .5-3.5Hz – Asleep
Theta – 4-7.5Hz – Meditation/Twilight – Waking or Falling Asleep
Alpha – 8-12Hz – Awake, Calm and relaxed
Beta – 13-25Hz – Focused, Fight or Flight
Gamma – 25-50Hz – Creative Bursts, also during REM sleep
NOTE: The edges of the states are fuzzy, so you will see some variation on the exact ranges for the frequencies.
When you hear a binaural beat tone for a certain amount of time (30 minutes or so) your brain will start to adopt the frequency you are listening to as its own. If you are listening to an alpha frequency binaural beat, your brain will change its underlying frequency to one that is more in the direction of Alpha from where it was before.
Entrainment exists all around us from the tendency of our heart to slow down when the pulse of a song is slower than our heartbeat to our tendency to clap in time with each other.
An example of this general entrainment phenomenon that you might be familiar with is a pacemaker. Your heart synchronizes itself to the frequency of the pacemaker. (Neural Entrainment on Wikipedia)
New Alzheimer’s Research at MIT
An MIT Alzheimer’s research study just published (Dec 8, 2016) shows that when you stimulate mice with Alzheimer’s disease using a 40Hz (Gamma) oscillating light for 1 hour, you substantially reduce the amount of beta amyloid plaques in their brains! AND memory function is also improved.
This is an amazing development in Alzheimer’s disease, and it’s an amazing recognition that stimulation with a frequency can cause the kind of positive action that wasn’t previously recognized by western medicine.
I emailed the lead researcher asking her if they had considered using sound as the stimulus instead of light, and she said:
You bet, we are on the auditory stimulation.
Hopefully you will see something in print on the auditory stim next year.
Needless to say, I’m excited to see what comes out next!
What does the Future Hold?
The study of sound as a tool for healing has generally been dismissed by mainstream medicine as quackery and pseudoscience. Perhaps as we study it scientifically, we will find that music has a more important place in medicine than has been acknowledged for the last few hundred years.
It’s easy to dismiss what you don’t understand, but it’s better to study it.
Give it a Try
If you are interested in trying out binaural beats yourself, here are a few free apps that you can use:
Gnaural – PC, Mac, Linux – Open Source binaural beats generator, Also has the ability to generate and save your own beat sequences. If you are interested in the beat sequences I’ve created, contact me, and I will email them to you.
Binaural – IOS – This is the App I use for binaural beats on my iPhone. There are lots of other free and paid apps for IOS, this is just the one I use and like the best. The only problem is that this one may be discontinued, because I can’t find it when I search.
Another IOS app I have used is: iBrainWave SE It’s not as flexible as Binaural, but it’s good, and it’s free.
If you have an app that you like for android, please leave it in the comments below.
And, if you have used Binaural Beats, let me know what your experiences have been in the comments section too!