When you apply slightly different frequency tones to each ear, a beating effect is created in your brain due to your brain's internal wiring. When listening to these tones, as you relax and let your mind go, your mind will naturally synchronize with the beat frequency.
So, for instance, when a pure tone of 400Hz is fed into one ear and a pure tone of 410 Hz is fed into the other ear (through stereo headphones), in your brain a third tone is produced at a frequency of 10 Hz - this is a binaural beat. Your brain then begins to resonate at 10 Hz which is known as the Alpha brainwave state.
In this way it is possible to tune the frequency of your brain waves to particular frequencies that you have selected.
| Delta | 1 - 4 Hz | Deep sleep, increased immune functions |
| Theta | 4 - 8 Hz | Deep relaxation, meditation, memory, creativity |
| Alpha | 8 - 13 Hz | Light relaxation, learning, positive thinking |
| Beta | 13 - 100+Hz | Normal waking consciousness, alertness |
These basic states can be further refined by using precise binaural beats. For example, a frequency of 3.4 Hz is good for aiding sound sleep. And to reduce stress and anxiety a frequency of 8 - 8.6 Hz is beneficial.
All of these frequencies occur in nature - the crashing of waves, a babbling stream, wind through trees, etc, and are usually associated with a relaxed state of mind, and as such, when used correctly are very safe. Native American Indians produce theta and delta rhythms with their tribal drum rituals.