Anyone who sleeps with white noise is likely to tell you they can't fall asleep without it. And when you count up all the apps and white noise machines on the market, it may seem like you've stumbled upon the holy grail of sleeping.
While sleep experts agree that white noise apps or machines (or the original version—fans) are definitely soothing, the data to back up whether it truly helps us sleep is limited at best. Yet with apps listed in the "Health and Fitness" category, and manufacturers who claim "sleep is just a click away," is there really any science behind it?
The Great White Way
For the people who say it helps them sleep, white noise functions as a kind of anti-noise, says Joseph Ojile, M.D., medical director and chief executive officer of the Clayton Sleep Institute. It's a redundant noise, something that distracts your brain but you don’t have to focus on.
Not everyone needs it to catch some zzzs, but for those who do, white noise dampens other sounds, sort of like snow muffles noise. Pink noise: effect on complexity synchronization of brain activity and sleep consolidation. Zhou J, Liu D, Li X. Journal of theoretical biology, 2012, Apr.;306():1095-8541. The whirring of a fan, an app, or a machine covers up all the little sounds that could be distracting to your brain—your partner’s snoring, a dripping faucet, or people talking outside your apartment on a Saturday night, says Christopher Winter, M.D., a fellow at the American Academy of Sleep Medicine and medical director at the sleep center at Martha Jefferson Hospital.
White noise aficionados know there are a ton of options to choose from (from gentle, light rain to a hurricane to the sound of a cat purring, for instance). Which one works best for you just comes down to personal preference, says Shalini Paruthi, M.D., a fellow of the American Academy of Sleep Medicine (AASM) and the director of the Pediatric Sleep and Research Center at Saint Louis University.
But if you tend to wake up in the middle of the night, she says to opt for a machine that'll keep humming all night rather than a timed app that may stop after an hour. Waking up in an environment that's different from what you fell asleep in can make it harder to doze off again, she explains.
Sweet, Routine Dreams
Winding down with a calming sound can be helpful, but making sure it’s part of a nightly bedtime routine is integral to a good night’s sleep, Paruthi says. Often they can be one in the same (lights off, fan on), but the effectiveness of white noise may actually come down to that routine aspect.
“Your body likes to anticipate what’s going to happen,” Winter says. “So if you always end your day by taking a hot shower, dimming your lights, and then turning on your noise machine, every night that your body does those things in that order at that time, it tells your brain sleep is coming up,” Winter says. It's essentially a stage cue for melatonin—enter sleep, right on time.
Easy enough for the 80-year-old’s in the room. But for those of us who don’t have quite such defined schedules (although Paruthi and Ojile both say that’s the gold standard), Winter says even just the routine of hearing your fan can be helpful.
The only danger arises when you feel like you can’t get to sleep without it, Winter says. As helpful as those routines are, there’s also a flip side, when people can't sleep without going through rigid motions, Ojile says. But it’s unlikely for white noise to create dependence in itself—that’s probably some level of anxiety talking.
If your partner truly hates the sound, whether it's waves or a gentle whir, you can wean yourself off the app by setting a timer that shuts it off after a certain amount of time. But if your sleepmate also likes the sound of the rainforest at night? There's no harm in pressing play nightly.
Anti-noise can create a helpful blankness for people who love it, but there’s nothing in the sound itself that will enhance your sleep. For others, it’s the same as going to sleep in a totally quiet room. More essential to sleeping like a baby is having a standard nightly wind-down routine to let your body know it’s time for some shut-eye.