White noise for babies: how loud, how long, how close

The short answer: set white noise to roughly the volume of a soft shower, place it a metre or more from the cot, and either use the timer or leave it on all night at a low level. Steady, low sound helps babies settle because the womb was never quiet.

Why white noise works

Inside the womb a baby hears a constant wash of sound: blood flow, heartbeat, digestion. Researchers estimate it sits somewhere around the volume of a vacuum cleaner. Silence is the unfamiliar part of the outside world, and a quiet room can make every creak and car door a wake-up call. Steady sound gives a baby something familiar to settle into and masks the noises of a normal household.

How loud

Quieter than most parents think. Aim for the level of a soft shower or gentle rain heard from the next room. If you have to raise your voice to talk over it, turn it down. Zazu machines like Dex the Dog have several volume steps so you can find the lowest one that still masks the house.

How close

Keep the machine a metre or more from the cot, never inside it or on the cot rail. Distance is the simplest way to keep the sound at a safe level where your baby's head is.

How long

Both approaches work. A timer that fades after 15 or 30 minutes helps a baby fall asleep and then lets the room go quiet. All night at a low volume helps babies who wake at every sound. Zazu's cry sensor sits between the two: the sound switches off on the timer and restarts on its own if your baby cries, so you are not the one getting up to press play.

Which sound

Newborns often settle fastest to a heartbeat. From a few months, rain or a slow shush tends to work best. Avoid anything with a tune; the brain follows melodies, which is the opposite of what you want. Pick one sound and keep it for at least three nights before judging it.

Will they become dependent on it?

They will come to expect it, the same way they expect a dark room and a familiar sleeping bag. That is a cue, not a dependency. When you want to stop, turn the volume down one step every few nights and let it fade out of the routine.

What to buy

For newborns and the pram, Suzy plays a heartbeat and clips on anywhere. For the cot, Dex the Dog has six sounds, a cry sensor and a timer. If your child is also unsettled by the dark, Emmy the Elephant combines white noise with a slow breathing light to copy.

This guide is general information from the Zazu Australia team, not medical advice. If you are worried about your child's sleep, breathing or development, talk to your GP or maternal and child health nurse.