In 2014, a study of sound machines kicked up a lot of questions about white noise. Researchers tested 14 machines (marketed specifically for sleeping babies), placed 12 inches from the babies’ heads and cranked them to max volume. When they measured how much sound reached the baby, they found that 3 devices exceed 85 dB.
The researchers warned that, if played at that intensity for 8 hours straight, that amount of noise (85 dB) would exceed safety standards and might reach a level that could hurt hearing. They advised: 1) moving machines as far away as possible, 2) playing them at 50 dB and 3) stopping the sound after the baby fell asleep.
Can Noise Machines Hurt a Baby’s Hearing?
That advice may seem logical, but I believe it is wrong...and even dangerous. By reducing infant crying and boosting a baby’s (and mother’s) sleep, white noise may prevent many of the terrible problems triggered by these 2 stressors including postpartum depression, SIDS and child abuse. But it only works if it is loud enough! As you can see in the figure below, white noise at 50 dB offers absolutely no benefit for your baby’s sleep. Sound doesn’t start boosting sleep until it gets to 60 to 65 dB.
Needless to say, don’t blast sound at the maximum volume...all night...right next to your baby’s head. However, loud sound for minutes (not hours) is super helpful for calming crying. And it’s a heck of a lot less trauma to your baby’s ears than her own crying!
Bottom line: When your baby cries, boost the sound–for several minutes–to the level of her cries. After she’s been asleep for 5 or 10 minutes, reduce the sound to the level of a soft shower, around 65 dB.
Did you know that SNOO Smart Sleeper is the only baby bed with a responsive white noise machine—that reacts to your baby's cries and delivers the right level to soothe her. The sound increases to match the level of fussing and decreases when she calms. And, all-night "rain-on-the-rooftop" sound helps reduce night wakings. Learn more.