Baby sleep sounds, done safely
Womb, shush, hairdryer and rain — synthesized live, with the two safety rules pediatric research actually asks for built into the tool: distance and volume.
Sound fades out gently when the timer ends. Manage it anytime in the bottom bar.
🎯 Crib Check — is it too loud where your baby sleeps?
Pediatric guidance suggests keeping sound around 50 dB at the crib (a 2014 Pediatrics study found several infant sound machines exceeded safe levels at max volume). Checking yours takes two devices and one minute:
💻 This device = the sound source
Press play on a sound above and put this device where your speaker normally lives — about 2 m from the crib.
📱 Your phone = the meter
Open this page on your phone (scan the code), tap Start Crib Check below, and hold the phone where your baby's head rests.
Listening…
Estimation only — phone microphones aren't calibrated meters. Everything stays on your device: no audio is recorded or sent anywhere.
Why noise soothes newborns
The womb is loud
Blood flow, digestion, a heartbeat — a fetus lives in continuous low sound, day and night. Silence is what's new and strange after birth. Our Womb preset recreates the familiar: muffled low noise with a soft 60 bpm heartbeat.
Parents knew first
Vacuum cleaners, hair dryers and instinctive shushing calmed babies long before apps existed. Every preset above is one of those time-tested sounds — without the electricity bill.
The research agrees
In the classic study (Spencer et al. 1990, Archives of Disease in Childhood), 80% of newborns fell asleep within 5 minutes with white noise — versus 25% without. Small, old study; matched by millions of exhausted parents every year.
The two safety rules
📏 Distance: 2 meters
Keep the phone or machine at least 2 m (7 ft) from the crib — never inside it, never clipped to the rail.
🔉 Volume: ~50 dB max
About the level of a quiet conversation. If you have to raise your voice to talk over it, it's too loud. That's what the green zone above — and the Crib Check — are for.
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), and never clip a speaker to the crib itself. Our Crib Check tool below helps you sanity-check this in your own nursery.
Which sound works best for newborns — white noise or womb sounds?
The womb is a low-frequency place: blood flow, digestion, a heartbeat. Deep continuous sound often works remarkably well in the first months, which is why our Womb preset layers a soft heartbeat over muffled low noise. Around 3-4 months, many babies do just as well with plain white or brown noise. Try both — the best sound is the one your baby settles to.
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 nap 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 the Crib Check a medical measurement?
No. It uses your phone microphone to give an estimate — microphones vary and are not calibrated sound-level meters. It is a sanity check to catch a clearly-too-loud setup, not a certified measurement. When in doubt, keep the source farther away and quieter.