Binaural or isochronic beats are different ways in which the sound can be presented to the brain. You may have heard of binaural beats as these are the best known entrainment method. With this, a sound of a slightly different tone is played separately to each ear. When this is done the brain will mix the two sounds and produce a frequency that is the difference between the two.
Sound Waves For Headphones
So, if for example, a tone of 400 hz is played in your left ear and one of 410 hz in your right ear, the brain will begin to produce waves of 10hz, the difference between the two.
So here is the answer to your insomnia problem. You want to sleep and so you would play your brain the sleep frequency.
Binaural or Isochronic Beats
Although the best known, it has been found by many researchers that binaural beats are not the most effective method of entraining the brain. Dr. Oster, in his 1973 paper in Scientific American, found that binaural beats were less effective than monaural and other types of beats. And Arturo Mans, in his 1981 paper, showed that isochronic beats were more effective than either binaural or monaural beats.
This is all a bit technical and I won't go into it in any more detail here. I really just wanted to show you that there are more and better ways to achieve entrainment than binaural beats because to read some sales material you would think that binaural was all there was.
In fact, any type of beat will produce entrainment, if it is played at the right frequency for long enough.
Most of the brain wave entrainment programs on the market use binaural beats to produce the entrainment effect but the much stronger effect of isochronic beats is better. Another benefit from isochronic beats is that you can listen without wearing headphones. It can be a little uncomfortable to wear headphones in bed.
Other related pages at Relax and Sleep