The maker of the Sleep Shepherd, an ear-hugging sleeping cap with built-in speakers, says it monitors your brain waves and “optimizes your time asleep” while “drowning out distractions like a snoring partner.”  

The product literature claims that the hat uses the natural patterns of your brain waves to generate sounds that simulate the soothing sensation of side-to-side swaying—similar to being in a hammock.

Does It Work?

The company points to small studies in Europe, one of 20 adults and another of 15 teens, to support its claims that the Sleep Shepherd sounds can influence brain wave signals and promote sleep.

“Biofeedback is a fairly legitimate way to train your body and alter your behavior,” says Nathaniel Watson, M.D., president of the American Academy of Sleep Medicine. “But these kinds of devices need to prove their worth more than they have up to this point.”

Our tester found that the sleeping cap was comfortable, though warm, and functioned well as a white-noise machine­—though, at $149, an expensive one.

Note that the Sleep Shepherd does not claim to be a medical device (intended to diagnose or treat a disease or condition), and it's not regulated by the Food and Drug Administration.