White noise for babies
It often works startlingly well — and it comes with exactly two safety rules. Here is the honest version, without the parenting-blog fluff.
Why noise soothes newborns
The womb is not a quiet place: blood flow, digestion and a heartbeat surround a fetus with continuous low-frequency sound day and night. Silence is what's new and strange after birth. Continuous noise recreates something familiar — which is why a vacuum cleaner, a hair dryer or a shushing parent has calmed babies since long before apps existed.
The classic study here is Spencer et al. (1990, Archives of Disease in Childhood): 80% of newborns exposed to white noise fell asleep within five minutes, versus 25% without. It is a small, old study — but it matches what millions of exhausted parents discover independently every year. White noise also masks household sounds (doorbells, siblings, dishes) that cut naps short.
The two safety rules
In 2014, researchers measured popular infant sleep machines and found that several, at maximum volume close to the crib, exceeded safe sound levels for infants (Hugh et al., Pediatrics). The fix is simple and costs nothing:
1. Distance: keep the phone or machine at least 2 meters
(about 7 feet) from the crib — never inside it or clipped to the rail.
2. Volume: aim for roughly 50 dB or less at the baby's position —
about the level of a quiet shower heard from the next room. If you have to raise your
voice to talk over it, it is too loud.
Follow those two rules and continuous noise is a low-risk, reversible, free tool. Ignore them and you are pointing a speaker at developing ears all night — don't.
Try it now (at grown-up distance)
Tip: many parents find brown noise's deeper texture works as well as white noise at lower perceived loudness — worth testing during the fussy evening hour rather than at 3am.
Frequently asked questions
How loud should white noise be for a baby?
Quieter than most machines ship at. After a 2014 Pediatrics study found some infant sound machines could exceed recommended limits at maximum volume, the practical guidance became: place the sound source at least 2 meters (7 feet) from the crib, keep volume at or below roughly 50 dB (about the level of a quiet conversation or gentle shower heard from another room), and never clip a speaker to the crib itself.
Should white noise play all night, or just at bedtime?
Both approaches are common and there is no strong evidence either way. All-night noise keeps masking working through the night; timer-based use limits total exposure. If in doubt, use a timer for settling and switch to all-night only if night wakings from external noise are the actual problem.
Will my baby become dependent on white noise?
Babies form sleep associations with whatever is present at bedtime — noise, rocking, feeding. A noise association is one of the easiest to keep (travel-friendly, free) or to fade later by lowering volume over a week or two. It is a reasonable trade-off, not a trap.
Is brown noise safe for babies too?
The same rules apply: distance and moderate volume. Some parents prefer brown noise because it is less hissy at the volumes that soothe newborns. The womb is a low-frequency place, and deep continuous sound often works remarkably well in the first months.
For the nursery, with the screen off
Our free iOS app Brown Noise Machine plays white, pink and brown noise all night in the background — set the volume, set the distance, and go (finally) sleep.
Download on the App Store