Are white noise machines safe?

What the evidence says

White noise machines are small speakers that play steady, soothing sounds to help babies fall asleep or block out household noise. Many parents use them, and some research shows they can help babies fall asleep faster and cry less.

The worry is about how loud these machines get. Researchers in Toronto tested 14 sleep machines and found that even at a normal distance, all of them were louder than the noise limit recommended for hospital nurseries, and three were loud enough that hours of exposure could theoretically damage hearing. A separate study of both machines and phone apps found similar results, especially when a device is placed inside the crib or turned up to maximum volume.

A major children's health group in the United States looked at this evidence and said sleep machines can still be used, but it is safer to keep the machine well away from the crib, use the lowest volume that still works, and not run it non-stop all night at high settings. Canada's own pediatric group also lists white noise as one option that can help soothe a crying baby, without raising a specific volume warning of its own.

Hearing damage from noise depends on both how loud a sound is and how long you're exposed to it, so a machine playing softly across the room is a very different situation from one blasting inside the crib for eight hours straight. No study has actually shown a baby who developed hearing loss from a home sleep machine; the concern is based on measuring the machines themselves, not on tracking outcomes in real children.

A sensible approach is to place the machine at least an arm's length or more from the crib, keep the volume low (roughly as loud as a quiet shower), and use it to help with settling rather than leaving it on at full blast all night.