White noise for a baby should stay at or below 50 decibels at the crib, roughly the volume of a quiet conversation or a gentle shower. The American Academy of Pediatrics recommends placing the machine at least 7 feet from your baby’s head, which naturally brings the volume down to a safer range. Getting the volume right matters because infant ears are more vulnerable to noise damage than adult ears, and many commercial machines can produce surprisingly loud output.
The 50 Decibel Target
There’s no single official decibel number stamped on a pediatric guideline, but the practical consensus among sleep consultants and pediatric researchers lands around 50 dB at the level of the baby’s ears. For reference, 50 dB is about as loud as moderate rainfall or a refrigerator hum. The AAP notes that the occupational safety threshold of 85 dB averaged over eight hours was designed for adults and “should not be assumed as safe for children or teens.” Babies need a significantly lower ceiling.
A good rule of thumb from the AAP: if the environment sounds too loud for you, it’s too loud for your child. When you stand next to the crib with the machine running, the sound should blend into the background. You shouldn’t need to raise your voice to talk over it.
Why Distance Matters More Than the Dial
Volume drops quickly with distance. A 2021 study testing 14 white noise devices found that at maximum volume and just 4 inches from the speaker, 64% of devices exceeded 85 dB. But when those same machines were moved to about 3 feet away, none of them exceeded that threshold, even at full blast. At minimum volume, no device exceeded 85 dB at any distance.
The AAP’s current recommendation is to place the machine at least 7 feet from your baby’s head. That distance alone provides a large safety margin. In practice, this means putting the machine on a dresser across the room or near the door rather than on the crib rail or a bedside table. If your nursery is small and 7 feet isn’t possible, turn the volume down further and aim for the farthest spot you can manage.
How to Check the Volume
A smartphone decibel meter app can give you a reasonable estimate, though it won’t be laboratory-precise. Research comparing Android sound meter apps against a calibrated meter found that most performed well at lower volumes (25 to 40 dB range), with nine out of ten apps achieving strong accuracy. Performance dropped at higher levels, particularly around 85 dB, where some apps underestimated the true reading. For nursery purposes, where you’re checking that sound stays in the 50 dB range, a well-reviewed app like “SPL Meter” or “Sound Meter” by Pony AI will get you close enough.
To measure, open the app and hold your phone where your baby’s head rests in the crib. Let it read for 10 to 15 seconds. If the number hovers around 50 dB or below, you’re in good shape. If it’s creeping toward 60 or higher, turn the machine down or move it farther away.
How Long to Run It
A scoping review of continuous white noise during sleep found that moderate-intensity exposure throughout the night showed potentially negative effects on early development in animal models, and human data generally pointed in the same direction. Lower-intensity exposure, by contrast, appeared to be beneficial. The researchers concluded that both intensity and duration should be limited on commercial devices.
The practical takeaway: keep the volume low and consider using a timer. Many machines have 30, 60, or 90 minute auto-shutoff settings. Running white noise during the falling-asleep phase, when it’s most useful for blocking household sounds and soothing your baby, then letting it taper off is a reasonable approach. If your baby wakes easily when the sound cuts out, a continuous low setting (well under 50 dB) is a better option than a loud one on a timer.
White Noise vs. Pink Noise vs. Brown Noise
Not all “noise” sounds the same, and different types may work better for different babies.
- White noise plays all sound frequencies at equal intensity, producing a steady “shhh” similar to radio static or a fan. It’s the most effective at masking sudden, unpredictable sounds like a dog barking or a door closing.
- Pink noise emphasizes lower frequencies, creating a softer sound like steady rainfall or wind through trees. Some research suggests it may promote deeper, more stable sleep.
- Brown noise goes even deeper, with a rumbling quality like a waterfall or distant thunder. It can be more comforting for babies who seem bothered by higher-pitched sounds.
All three types follow the same volume and distance guidelines. The “best” choice is whichever one helps your baby settle. It’s perfectly fine to experiment.
Common Setup Mistakes
The biggest mistake parents make is cranking the volume up to drown out a noisy household. A white noise machine doesn’t need to overpower every sound in the house. It works by creating a consistent audio backdrop that makes other noises less jarring by comparison. Even at 50 dB, it smooths out the contrast between silence and a sudden noise, which is what actually wakes babies.
Another common issue is placing the machine inside the crib or clipping a portable sound device to the crib rail. Portable sound machines designed to attach to strollers or car seats are convenient for travel, but they sit far too close to a baby’s ears when clipped onto the crib. Always use them from across the room when you’re at home.
Finally, avoid using white noise to compensate for an already loud environment. If your home regularly exceeds 60 to 65 dB from traffic, construction, or other sources, adding white noise on top of that raises the total sound exposure. In that case, addressing the ambient noise first (closing windows, adding soft furnishings to absorb sound) will do more good than turning the machine up.