Why small babies enjoy white noise

There is surprisingly little activity taking place, for the amount of noise coming from the room. Wired with sleep deprivation, Nic slouches in an armchair, holding a hairdryer the wrong way round, blasting air at the wall behind him. His tiny son is lying perfectly still, across his chest.

“Look at his face,” Nic says, with quiet excitement.

As I move to see the baby’s face, I’m expecting an expression of serenity. Instead Jake’s eyes are wide and his mouth is forming a perfect ‘o’. This isn’t bliss, this is fascination. Right now, the hairdryer is the most interesting thing in Jake’s world – albeit a world he’s known for just thirteen days.

“They sell white noise generators. A recording of white noise, with a player and a speaker,” Nic says. “But people don’t realise you can use a detuned radio, or a hairdryer. For some reason, it’s the ultimate distraction. They love it.”

To prove the point, he switches off the hairdryer. The trance broken, Jake begins to squirm.

Like all babies of his age, Jake’s digestive tract is not yet fully online. As it’s now a couple of hours since his last feed, Jake has wind; his writhing limbs respond to the miniature storm inside his belly.

White noise is the only thing that takes his mind off it and, with another click of the hairdryer switch, the baby is once again mesmerised by the sound of whooshing air. It’s like magic.

If you were to walk into this room, you might think nothing was happening; it’s surprisingly calm in here despite all the din. The hairdryer noise is creating a rare moment for Nic to relax. But right here, right now, everything is happening for baby Jake. The hairdryer evidently means something. But what exactly?

Why do babies like white noise?

Here’s the theory. When a baby is born, it’s a massive change in living conditions. The world ‘in utero’ is one of constant motion – every time mum moves, baby is moved. It’s also extremely loud, with the sound of whooshing blood greater than the noise from a vacuum cleaner.

Imagine coming from that jiggly, noisy environment to one where everything is dead still and eerily quiet. It would unnerve you. So small babies have a low threshold to discomfort; they are a bit freaked out from the moment they are born.

That’s why slowly rocking, or gently jiggling, a baby, makes them feel calm. (Baby Jake particularly enjoys having his pram pushed over the tactile paving you get near pelican crossings. It’s the guaranteed way of getting him to sleep.)

It’s also why the sound ‘ssshhh’, tends to make babies go quiet; it simulates the sound of rushing blood in the womb, which sounds like home to a newborn. And if that white noise is nearly as loud as a vacuum cleaner, so much the better.

These are the theories of Dr Harvey Karp who has studied the baby-calming techniques used by mothers across the world and was struck by the similarities. Rocking or gently jiggling the baby is common, as is making a loud ‘ssshhh’.

He also noticed the prevalence of swaddling – loosely wrapping the baby in cloth – his theory being that the resulting restriction of the baby’s limbs further recreates the conditions in the womb.

Based on his observations, Dr Karp formulated a five-step plan to calm a small baby, which he demonstrated on Richard and Judy in 2008. The interesting part starts at 3min 30 seconds.


The five steps are:

  1. Swaddling
  2. Laying the baby on his/her side or stomach
  3. Swinging, or rocking, or jiggling
  4. Shushing
  5. Giving the baby something to suck

Karp is keen to stress that he uses a swaddling technique that does not restrict the baby’s hips, which is important for proper growth.

It’s striking how loudly the doctor shushes, and how close to the baby’s ear he does it, to create white noise.

Karp advocates these five techniques in sequence, but I wonder if this is strictly necessary. Baby Jake was happy with just two of them: laying on his front, on his father’s chest, and white noise.

If you’re a parent with a restless newborn, Harvey Karp’s method is surely worth a try – he says it calms 98% of babies. Or you may simply want to try Nic’s technique and keep the hairdryer next to the sofa.

UPDATE: Nic and his partner now have a white noise app on their mobile phones to help Jake drift off to sleep, which is especially useful when he’s grouchy in his car seat. Jake that is, not Nic.