In short
- Volume: white noise at the cot should stay at or below about 50 dB(A), quieter than normal conversation.
- Distance: the white noise machine as far from the baby as possible, never in the cot or on its rail.
- Time: white noise on a timer rather than all night at full volume.
- Type: white, brown and pink noise differ only in how they sound; none is proven better.
Not medical advice: a parent wrote this guide, summarising published research; if you are worried about your baby's sleep or hearing, talk to your paediatrician.
Does white noise help babies sleep?
White noise helps some babies fall asleep faster, but the evidence is thin. In a randomised trial (Spencer et al., Archives of Disease in Childhood, 1990), 16 of 20 newborns aged 2 to 7 days (80 %) fell asleep within five minutes with white noise, compared with 5 of 20 (25 %) in the group without it.
The Spencer study was small, included only newborns and measured how quickly babies fell asleep, not how long they slept. The common explanation, that steady noise resembles the sounds of the womb and masks sudden noises such as doors, dogs or traffic, is plausible but not proven. White noise is a tool worth trying, not a cure for poor sleep.
How loud should white noise be for a baby?
White noise for a baby should be quiet at the cot, at most about 50 dB(A). That is the limit that Hugh et al. (Pediatrics, 2014) cite as recommended for hospital nurseries, and it is quieter than normal conversation, which the US National Institute on Deafness and Other Communication Disorders (NIDCD) puts at 60 to 70 dB(A).
Hugh and colleagues (Pediatrics, 2014; 133(4): 677–681) measured 14 infant sleep machines at maximum volume at 30, 100 and 200 cm. At 30 cm every machine exceeded 50 dB(A), and three exceeded 85 dB(A), which, played for more than 8 hours, would exceed occupational noise limits for adults.
| Level | What it means | Source |
|---|---|---|
| up to 50 dB(A) | recommended limit for hospital nurseries; a good target at the cot | Hugh et al. 2014 |
| 60–70 dB(A) | normal conversation | NIDCD, 2025 |
| up to 70 dB(A) | unlikely to harm adult hearing, even after long exposure | NIDCD, 2025 |
| 85 dB(A) and above | long or repeated exposure can cause hearing loss; 3 of 14 machines exceeded it at 30 cm | NIDCD, 2025; Hugh et al. 2014 |
Without a meter, a simple rule works: white noise at the cot should be quieter than your normal speaking voice. The Zibko app caps Sleep mode at 60 % of the phone's volume and shows a live estimate in decibels at 2 m. It is an estimate from the volume setting, not a measurement, because phone speakers differ.
How far from the cot should a white noise machine be?
A white noise machine should be as far from the baby as possible and never in the cot or on its rail; in Zibko we recommend at least 2 metres. Hugh and colleagues (2014) give the same advice, because the sound is loudest right next to the cot.
White noise gets quieter with distance: outdoors by about 6 dB each time the distance doubles, indoors a little less, because sound reflects off the walls. So place the phone or white noise machine like this:
- on a chest of drawers or shelf across the room, not on the cot rail;
- never in the cot, under the mattress or next to the baby's head;
- with the charging cable out of the baby's reach;
- with the phone in Do Not Disturb or flight mode, so calls and notifications don't wake the baby.
Can white noise play all night for a baby?
White noise can play all night, but researchers advise a shorter time: Hugh and colleagues (2014) recommend running infant sleep machines for a limited time and at low volume. Noise exposure adds up over time, so with all-night noise it matters even more that it is quiet and far away.
A practical answer is a timer that turns the white noise off once the baby is soundly asleep. Zibko's Sleep mode plays for 30 minutes, 1 hour, 2 hours or all night; over the last 3 minutes the sound fades slowly, so a sudden stop doesn't wake the baby. If your baby wakes when the noise stops, make the timer longer and keep the volume low.
White, brown or pink noise: which is best for babies?
No study shows that white, brown or pink noise is better than the others for babies; they differ only in how deep they sound. Choose the noise that settles your baby best, and play it quietly.
| Noise | What it sounds like | Technically |
|---|---|---|
| White noise | bright, sharp "shhh", like radio static | equal power at all frequencies |
| Pink noise | softer, like steady rain | power falls by 3 dB per octave |
| Brown noise | deep and muffled, like a distant waterfall | power falls by 6 dB per octave |
For sleep, Zibko has white noise, deeper brown noise, steady rain, a slow heartbeat, a gentle "shhh" and Brahms' lullaby. The same rule applies to all of them: volume and distance matter more than the type of noise.
Is white noise safe for babies?
White noise is reasonably safe for babies when it is quiet, far away and on a timer. The main risk described in the 2014 Pediatrics study is a machine that is too loud, too close to the baby's ears and plays for a long time.
- About 50 dB(A) or less at the cot, never at maximum volume.
- The machine as far away as possible, never in the cot or on the rail.
- A timer instead of non-stop playback, when you can.
- White noise does not replace a safe sleep space and an adult's supervision.
Can a baby get used to white noise?
A baby can get used to falling asleep with white noise, just as with any part of the bedtime routine, such as a bath or a lullaby. There is practically no research on whether babies become "dependent" on white noise, so nothing reliable can be said about it.
If you want to stop using white noise, you can turn it down gradually over several nights or shorten the timer. That is a practical suggestion from parents, not a studied method. If you have questions about sleep or hearing, for example if your baby doesn't startle at loud sounds, talk to your paediatrician.
Baby crying on car journeys? Read Why babies cry in the car, and what helps.
Sources
- Hugh SC, Wolter NE, Propst EJ, Gordon KA, Cushing SL, Papsin BC. Infant sleep machines and hazardous sound pressure levels. Pediatrics. 2014;133(4):677–681. PubMed
- Spencer JA, Moran DJ, Lee A, Talbert D. White noise and sleep induction. Archives of Disease in Childhood. 1990;65(1):135–137. PubMed
- National Institute on Deafness and Other Communication Disorders (NIDCD, NIH). Noise-Induced Hearing Loss, updated 16 April 2025. nidcd.nih.gov