My difficult child sleeps with a sound machine. She has been for at least since she was about 3, maybe younger. Can't sleep at night without it. If the power goes out, we put batteries in. She has complained that she hears this hu hu hu (almost like a heavy breathing) in her ear or buzzing or ringing. My father has slept with a sound machine since I was 9 or 10. he has buzzing in his ears and is losing his hearing, but I think it's because of him being in construction his whole life. I sleep with a sound machine, but don't have to. I only do it to drown out some of the noise the kids make when they get up in the morning. I've gotten used to it and notice I don't sleep as well without it now. I'm just curious....how many of your difficult children sleep with a sound machine? Why and is it because of a sensory issue or is it the bipolar or something else? Who will possibly go and buy one for their difficult child, after reading this post?