White Noise for Babies: The Complete Guide

White noise is one of the most evidence-backed tools for infant sleep. Here's everything you need to know — including the things most guides get wrong.

Why White Noise Works

The womb is loud. Research measures it at around 85–95 decibels — equivalent to a running vacuum cleaner — a constant whooshing, pulsing sound. After 9 months of this, a quiet room is actually foreign and overstimulating. White noise mimics the womb environment and activates a calming reflex in young infants. It also masks sudden household noises that interrupt sleep cycles.

How Loud Should It Be?

The AAP recommends keeping white noise machines below 50 decibels and placing them at least 7 feet (2 metres) from the baby's head. A sound level meter app on your phone makes it easy to check. Too quiet is less effective; too loud causes unnecessary noise exposure. 50–60dB at the baby's head position is the target range.

Which Type Is Best?

True white noise (equal energy across all frequencies) is most effective for newborns. Pink noise (slightly bass-heavy) is preferred by some older babies and many adults. Brown noise is the deepest, most womb-like sound. Nature sounds like rain and ocean waves are effective for older babies and toddlers who respond better to variety. The "best" type is the one your baby responds to — try a few.

All Night vs. Just for Falling Asleep

Running white noise all night is significantly more effective than using it only for settling. The reason is sleep cycles: babies rouse at the end of every 45–50 minute cycle. If white noise is playing during initial sleep but stops, the sudden silence at 1am can fully wake them. Keep it running from when they go down to when they wake for the day.

When to Stop

There's no developmental reason to rush stopping white noise. Many toddlers sleep better with it than without. When you do decide to stop, fade it out gradually over 2–3 weeks rather than going cold turkey.