"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Picture this: you've just applied your favorite night cream and made the bed with a fresh pair of sheets.

Getting a good night’s sleep is hard. A third of all American adults report getting less than the daily recommended amount of sleep nearly every night. Too little noise, and the mind starts to race.

“The sound machine can generate any of several types of sound, from nature [or] music,” Dr. Cory Portnuff, an audiologist at the University of Colorado Health’s Hearing and Balance Clinic, says. In ...