Neuroacoustic studies at The Center for Neuroacoustic Research show that listening to sounds based on different brainwave frequencies can significantly increase one's ability to achieve a desired state of mind. So it's nice to know that an enterprising company has collected all these sounds (based on Delta, Alpha, or Theta brainwave frequencies) into the Tranquil Moments(R) Sound Therapy System . This system boasts that it can "naturally" coax your brain to "match" these frequencies and possibly enter healthier states of sleep, relaxation or renewal.
So say that you want to relax; try listening to sounds that activate your Alpha brainwave patterns like Thunderstorm ("the sound of distant thunder as gentle rain falls upon a remote lake.") You'll be off into zzzz-land before you know it. (Unless you are afraid of thunder and then you should probably choose another sound.) This system is available for $99 from brookstone.com where customers have given it a 4 star rating (out of five stars). Brookstone says that they worked in close partnership with sound therapy expert Dr. Jeffrey Thompson.
And while you are at it, why not combine with other activities? Drink a cup of Organic Bedtime tea by Yogi Tea while listening to Summer Night (chorus of crickets and NASA-recorded sounds from Jupiter) for a restful night's sleep. (But don't fall asleep holding the cup of tea....) Or, try listening to Meditate (enlightening tones of Tibetan singing bowls) while doing Yoga. Let me know if you have a combination that you really enjoy.
For more ideas for sound therapy check these offerings from amazon.