Play an audiobook all night to help distract an otherwise excessively active mind. Use a book greater than 8 hours long. Too loud is not helpful, but too soft can make you strain to hear and potentially wake you up. Too interesting can be a problem so consider a story or book you are already familiar with. A science or history book you have already read is perfect!
If you are one of the 15% of the population that suffers from tinnitus, then environmental sounds can help you lose that incessant ring tone into the background.