Whenever an individual undergoes an astral projection or an out of body experience, the brain is generating waves (frequencies) in the range of 4 to 7 Hz (Hertz are the measuring unit for frequencies). These are called theta waves and they are the same ones occuring when we dream, are in deep meditation or in a state of hypnosis. Compared to our normal awake and busy states of mind (13 to 40 Hz - beta waves), the theta waves are slower. We are then much more relaxed.
To get the brain to generate the theta frequencies we need to relax our senses, mind an body to a significant extent. Binaural beats (available at www.outofbodyexperience.info) are sound waves that influence the brain into generating these desired frequencies and they will be the subject of the next post.