White Noise and Sound Machines at Bedtime: Do They Actually Help?

Somewhere between a nursery must-have and a mild parenting controversy sits the sound machine: a small speaker that hums, rushes or shushes all night. Some families cannot sleep without one; others have never owned one and sleep just fine. Here is what a white noise machine actually does, and where it earns its place.

What white noise actually does

A continuous, even sound does two things well: it masks sudden noises — a door, a sibling, a passing car — that would otherwise startle a light sleeper awake, and it becomes part of the falling-asleep routine itself, so the sound alone starts to signal "this is sleep time". It is not a sedative and will not fix a bedtime that is fighting the child for other reasons.

Choosing one, if you choose one

• Pick continuous over looping. A short track that loops every thirty seconds is more distracting than helpful; true white, pink or brown noise does not repeat in a noticeable pattern.
• Keep the volume low. Roughly the level of a quiet shower running in another room is plenty — louder is not more effective, and can affect developing hearing over time.
• Place it away from the cot or bed. Across the room, not clipped to the rail — distance does the same masking job at a gentler volume.
• Trial it with a phone app first. Before buying a dedicated machine, a free app for a few nights will tell you whether your child even responds to it.
• Turn it off during the day. Keeping the sound exclusive to sleep protects the association that makes it useful in the first place.

When to skip it altogether

Some children are startled rather than soothed by an unfamiliar machine, especially very young babies or sensory-sensitive children — in which case it is doing the opposite of its job. Travelling without the usual machine can also unsettle a child who has come to depend on it completely; it is worth keeping the routine flexible enough to work without one, at least occasionally.

A quiet story does a similar job

A slow, steady reading voice offers much of what white noise offers — rhythm, predictability, a sound to settle into — without any equipment at all. These stories lean on gentle, repeating sounds inside the plot itself: water, song, humming shells.

Whether the last sound in the room is a machine or a voice, the same rule applies: keep it steady, keep it quiet, and keep it the same most nights. For more on building that predictability into the wider evening, see our guide to a calm routine on a hot night — another case where the environment matters as much as the routine — or browse the full bedtime collection.