The result of brainwave entrainment is quite amazing when you consider all the things we do, all the drugs we take to alter our consciousness, when there is an alternative that requires no pills, smoking, or injecting. Another name for this phenomenon is frequency following response. When the user is exposed to frequencies that closely match that of brainwaves, the brainwaves begin to naturally match their own frequencies to the frequency of the stimulus, this in entrainment.
Our brainwaves operate at frequencies well below 40Hz, and there is no way to accurately play these subsonic frequencies over conventional speakers. This is why alternative methods but be used to re-create these subsonic tones. This stimulus could be aural, visual, or a combination of the two. This process has been proven and practiced for almost two centuries, and there is even evidence that the process dates back to 200 AD.This practice has been done for so long because it really works, its great for meditation, relaxation, and even a bit of a high.
The Dream Machine is an early of example of an aural-visual brainwave entrainment machine. There are quite a few companies out there now selling complex machines that include a visor that flashes lights at specific frequencies while playing binaural tones over headphones. I mean, thats cool, maybe if your fine with walking around looking like Jordie LaForge from Star Trek. But if your like me and want just the audio end of it, (you know, so you can go out in public not looking like a robot!) then you want to check our Binaural Beats.