Check out http://brainwaventrainment.net for the full brainwave entrainment experience
There are 3 types of Brainwave Entrainment of differing popularity:
Binaural Beats, the most commonly known type of Brainwave Entrainment
Isochronic Tones, the second most commonly known type of Brainwave Entrainment
Monaural Beats, the third most commonly known type of Brainwave Entrainment
