We tend to associate white noise with babies…and for good reason. White noise mimics sounds baby has recently been hearing all day and night in the womb. (It’s very noisy in there!) So when toddlers hear that familiar low, rumbling sound coming from a white noise machine, it does something quite magical. This helps activate their innate calming reflex, or their built-in “reset button” to bring calm and sleep back.
In fact, white noise – a combination of various sounds at different frequencies – helped 80% of babies fall asleep in just 5 minutes, according to a study of 40 babies published in the peer-reviewed journal Archives of childhood illnesses.
In short, we are all born with a craving for white noise. And that desire doesn’t just…poof!-disappear once we run out of layers. This is changing however.
When babies reach around 3-4 months, their innate calming reflex wears off, but white noise continues to work as an amazing sleep aid. The reason? First, white noise helps distract children from some common sleep hiccups that can occur, such as teething pain, a slightly stuffy nose, or mild hunger. Essentially, white noise gives baby something else to pay attention to, which helps them fall asleep.
Second, once you start using white noise during your baby’s bedtime routine, he starts to expect it. Toddlers recognize that white noise means it’s time for bedtime. Everything is very Pavlovian. Think about it: do you still get a little sleepy when you get a little jostled around while driving a shotgun in the car, listening to the steady hum of the freeway? If so, you already know that the power of rocking and white noise lasts long after infancy.
But even if you never heard white noise as a baby, it could still work for you. Once you start adding white noise to your own bedtime routine, your adult brain will soon start connecting sound to sleep…just like little babies do.
Another reason why white noise works as a sleep aid, regardless of your age, is that it drowns out sleep sounds that could be disruptive, such as a noisy television next door, a truck passing by your window. room or a snoring partner. Appropriate white noise creates a sort of “sound blanket” that masks the sudden changes in sound coherence that often wake people up.
A 2017 report in Frontiers in Neurology found that white noise used in noisy hospitals helped reduce the time it takes patients to fall asleep by about 40%. The key, of course, is to select the law white noise. Low-end sounds that are buzzy, hypnotic, and constant, like the monotonous rumble of car journeys, do the trick. Inconsistent sounds, such as music, waves, or birds chirping don’t provide the same sleep rewards.
Ultimately, I like to think of white noise like I think of my favorite pillow or my cozy duvet. It’s yet another healthy sleep tool designed to help us get to dreamland and stay there.