White Noise for Baby Sleep

The two safety rules that matter most

Pediatric noise guidance for infants comes down to two numbers: volume and distance.

• Volume below 50 dB SPL at the crib. That's quieter than a normal indoor conversation. Most parents err on the side of louder than this; resist the urge.
• At least 7 feet (about 2 meters) between the device and the crib. Across the room is fine. Bedside table is usually too close.

The American Academy of Pediatrics' citations suggest these as the safe envelope. Inside that envelope, continuous broadband noise is considered acceptable for infant sleep. Outside it — very close placement, or volumes much above 50 dB — the long-term hearing-protection concern starts to apply.

Why pink instead of pure white

Pure white noise (flat across the spectrum, 0 dB/oct) sounds bright and hissy. It works as a masker, but small ears are more sensitive to high frequencies, and pure white can feel harsh over many hours. Pink noise rolls off at −3 dB/oct, putting more of the energy lower and softer. It sounds more like a steady rain or distant waterfall, and it's the most common default in pediatric sleep guidance.

Brown noise (−6 dB/oct) is softer still — deep, low rumble. Some babies prefer it, especially when room temperature ambient noise is on the higher-frequency side (noisy HVAC, neighbours). Try both. The "right" choice is whichever your specific baby settles to most reliably.

How to set it up

1. Place your phone or computer at least 7 feet from the crib. The dresser across the room is ideal.
2. Press play. Pink is selected by default.
3. Adjust volume so the noise is audible but not loud. As a rough check: if you walk over to the crib and the noise feels louder than a normal indoor conversation at the crib level, it's too loud. Drop it.
4. Use the warm ↔ bright slider to taste. Most parents prefer it slightly warm for overnight.
5. Add NoiseMoon to your home screen (your phone will prompt you). Tomorrow night you can launch it in one tap, no opening a browser.

An external Bluetooth speaker placed across the room often works better than the phone's own speaker — you can keep the phone with you while the noise plays consistently from one location.

What the research actually says

The most cited research is a 1990 paper showing that continuous broadband noise reduced infant crying-to-sleep time substantially in a hospital setting. Many follow-up studies have replicated the basic effect. The hearing-safety concerns come from a 2014 study that measured infant sound machines and found many produced volumes above safe thresholds at typical placement distances — which is the source of the "below 50 dB at the crib, 7 feet away" guidance most pediatricians cite today.

What the research doesn't say with confidence: that white noise is necessary for infant sleep, that babies who use it become dependent, or that one specific noise color is universally better. The available evidence supports it as one helpful tool with sensible volume limits, not a magic sleep solution.

What about leaving it on all night?

Many pediatric sources are okay with overnight use as long as the volume and distance rules are observed. Some parents prefer to fade it out after the baby is asleep using the sleep timer. Both approaches work for most families. NoiseMoon's sleep timer (the no zzz button) lets you set a fade duration; the noise gradually quiets to silence over the timer window so there's no abrupt stop that can wake a light sleeper.

One common trap: parents set the volume while the baby is asleep, then crank it up later when the baby cries, and forget to turn it back down. The cumulative exposure climbs that way. A consistent volume, set during the day at a known level, is safer.