To understand binaural beats it will help to have a basic understanding of the different brainwave states called beta, alpha, theta, and delta.
Beta - Throughout the day our brains are in the beta range with a frequency of about 12hz and up. At this level we are active, busy, and all our emotional responses are at this level. People who are over active, or often depressed, irritable, angry etc., often lose out on the recuperation and recharging that takes place when we are relaxed in the alpha, theta, and delta levels.
Alpha - When we begin to relax and begin to get drowsy, but are still awake and conscious (maybe at pre-sleep) we are said to be at the alpha level which is about 7hz-13hz.
Theta - When we dream, or are in deep meditation, we are at the theta level (4hz-7hz).
Delta - During deep dreamless sleep where there is a complete loss of body awareness we are at the delta level (0-4hz).
So where do binaural beats fit in to all this?
Binaural beats are not a physical noise coming into either the right or left ears. Rather binaural beats are a 3rd tone manufactured by the brain when two different tones (at different hz levels) are played in each ear using stereo headphones. For the binaural beat to be perceived the frequency of the two different tones coming into each ear must be below 1000hz, and no more than 30hz apart. If they are more than 30hz apart you will simply hear a tone in each ear, one louder than the other. But if the difference between the beats below 30hz you hear that "phantom" binaural tone sort of in your head.
For example if you play a tone of 200hz in the left ear, and a tone of 190hz in the right ear (with the difference being 10hz) a beating tone will be perceived which is the binaural beat. What ever the difference is between the tones coming into the ears (in this example the different is 200hz-190hz=10hz) the binaural beat will be that difference (in this case the binaural beat is 10hz).
If you have grasped what has been written thus far then you can easily grasp the concept of binaural beats.
It has been scientifically verified that if you consistently listen to a binaural beat, for example, that is beating between 7hz-13hz, your brain will naturally tune in to that hz level and bring you to the alpha level (which as mentioned at the beginning is roughly between 7hz-13hz). Taking it a step further, if you listen to a binaural beat that is at about 4hz-7hz your brain will adjust to the theta level, and you may experience deep meditation, or lucid dreaming (dreaming while conscious), or even astral projection. (It can take listening to a recording daily for a few weeks for some people before they see results. It depends upon the individual). By listening to a binaural tone that is below 4z you may totally zone out and lose all body awareness as you plung into the delta level. Or, to improve memory, binaural beats are made at about the 16hz-24hz range (well into the beta range). And so on and so forth.
As a result of this discovery several different companies and products have come into being promoting their particular binaural recordings. Most of these binuaral recordings are mixed in with music such as nature sounds, or instrumental sounds. Bare binaural recordings may be dull to listen too. But with music mixed in with the binaural beats it is more pleasant to listen to, and has the same affect on the brain.
Below you will find video information about binaural beats:
