Tibetan Singing Bowls with Binaural Beats
Binaural beats are a way of synchronizing your brain waves (which are measured in hertz) with the hertz of the binaural beat. The brain has a frequency following response which causes this to occur. This works best with headphones and is useful for meditation or relaxation.
Here is an article from Wikipedia about Brainwave Entrainment: en.wikipedia.org/wiki/Brainwave_entrainment
The brainwave states (Beta, Alpha, Theta, Delta) are listed on this page (scroll down to the table) en.wikipedia.org/wiki/Electroencephalography
here's a basic rundown of the brains states:
Beta - 30hz-13hz - your normal awake state, in higher ranges or above 30hz you may be experiencing stress. In this case, you gotta chill!
Alpha - 13z-8hz - a relaxed and reflective state
Theta - 8hz-4hz - a very meditative state or getting drowsy and drifting off, if your sleepy)
Delta - 4hz and below - deep sleep or a very deep meditative state. Buddhist Monk's brainwaves have been measured in this state during meditation.
In the unlikely event that you experience any unusual physical or mental discomfort, immediately discontinue use.