It is soothing and will send you into a relaxing trance state after a about 20-30 minutes or so. I've used it while in pain and I'm not going to say it works absolutely, fantastically, brilliantly, great but it does work to a degree and will help you relax if there is no other options.
Listen with stereo headphone/earphones or it won't work and try not to think, kinda like meditating but focus on the sound. Oh and lie down on your bed comfortably and don't move.
Take a deep breath. Out and in. Out and in. Feel yourself getting calmer. Relax into a peaceful state. You're in a happy place with no cramps or aches of any kind. You are made of lovely silken clouds. You feel no pain. Now close your eyes and think of pretty grassy meadows or some other kind of serene crap, and fall into a blissful sleep.