Analysis has shown that some brainwaves, like intense relaxation, are ideal for learning and retaining new information while delta brainwave states promote relaxed healthy sleep. Until the adaptation of binaural beats tapes, CDs and MP3s, the only technique to create deliberate changes in your brainwave patterns was with deep meditation. For thousands of years this type of meditation has only been possible for practitioners of meditation with over 20 years experience, such as Zen Buddhist Monks.

via Binaural Beats | Meditation | Health and Nutrition Guidelines.