When you hear a different frequency tone in each ear, your brain will actually perceive two other "phantom" frequencies which are the average and the difference of the two original frequencies.

For example, a 500 Hz sound in one ear and a 510 Hz sound in the other ear will cause you to perceive a 505 Hz tone that pulses 10 times per second.

This happens normally in nature when two sound waves of different frequencies interact, but the human brain also produces this effect internally, even when each sound is isolated to a single ear. If the two sounds are close enough in frequency, the brain will produce these binaural beats.

Under the right frequency and volume conditions, you'll be able to perceive them consciously, so it isn't merely a subliminal effect.

These binaural beats "entrain" brainwave patterns - your brainwaves will synchronize with the beats if the beats fall within a certain range. By manipulating the individual sound frequencies in each ear, binaural beats can automatically adjust your brainwave patterns to "dial in" to a certain frequency and stay there. This effect happens automatically and doesn't require conscious effort.

Various brain frequencies are associated with different states of consciousness, including beta, alpha, theta, and delta.

Beta is your normal waking state.
Delta is the stage of deep, dreamless sleep.
Alpha and Theta are states of deep relaxation where improved concentration, memory, and creativity are commonly experienced -- they're also states associated with dreaming.

Brain entrainment targets somewhere in the alpha-theta range.

Brain Entrainment Products

The best two products on the market today are:

OptiMindzation - Stephen Pierce
Paraliminal CD's - Centerpointe Research Institute's Holosync technology.