How loud, and how far from the crib
Distance does more than the volume slider does, and there are numbers behind that. In 2014, researchers writing in Pediatrics played 14 infant sleep machines at full volume and measured them at three distances. Every one was louder at 30 cm, roughly the distance of a crib rail, than hospital nurseries allow, and three were loud enough to breach an adult workplace limit over an eight-hour shift. Their advice was to keep the machine as far from the baby as the room allows, never in the crib or on the rail, at the lowest volume and for the shortest time.
So do it in that order. Put the device across the room first, at crib height or above and pointing away, then start the sound, walk over and set the level standing beside the crib. Doing it the other way round is how people end up with a loud speaker turned down a little. A check that needs no equipment: someone talking normally from the doorway should still be easy to hear over it. If you'd rather have a number, a sound meter app at crib height gives you a rough one, and it's worth doing once. Anything you're unsure about is a question for your pediatrician.
Don't leave the phone by the crib
The usual setup is a phone propped against the crib bars, because that's where you were standing when you started the sound, and at three in the morning it's the easy thing to do. It puts a small, bright speaker within arm's reach of an ear that has no way of moving away from it. Carrying it to a shelf across the room takes ten seconds and does more than any change on this screen.
One softer point, and it isn't a safety one. If the sound runs for every nap and every night for a year, a quiet room starts to feel unfamiliar, and you'll have some unwinding to do later on. Nothing goes wrong, and it is easier to loosen early than late: drop the level a notch every few nights, then shorten the timer so the room goes quiet once the hard part of the evening is over.
Why it opens quiet
The slider starts low, and it assumes a speaker across a room: not a phone on the crib rail, and nothing in a baby's ears. Treat it as a place to begin. No slider position is safe on its own, because what reaches your baby depends on the device and how far away it sits, which is why the walk over to the crib does more than any setting on this screen.
What a nursery sound is for is softening the things you can't control: a door, a television in the next room, an older sibling who doesn't whisper. It isn't meant to be audible over crying, and turning it up until it is competes with the one sound you actually need to hear. It won't make a baby sleep, either. A baby who is hungry, too warm or working through something new isn't a volume problem, and that's worth remembering before you reach for the slider again.
Setting it up tonight
- Put the phone or speaker across the room first, well away from the crib, at crib height or above and pointing away.
- Press play. The preset opens at white noise 40%, with the sleep timer set until morning.
- Walk over and set the level standing at the crib, not at the device. Someone talking normally in the doorway should still be easy to hear over it.
- Tap 30 min or 60 min instead if you only want cover for the settling, which is closer to the shortest-time advice.
Frequently asked questions
How loud should white noise be for a baby?
Clearly quieter than a speaking voice, judged from beside the crib and not from the speaker. Where the speaker sits does more than the volume slider does, so move the device across the room first, then set the level. When researchers measured 14 infant sleep machines at full volume in 2014, all of them were louder at 30 cm than hospital nurseries allow, which is why the advice is the lowest volume and as far away as the room allows.
Where should the speaker go?
As far from the crib as the room allows, at or above crib height, pointing away. The setup to avoid is a phone propped on the crib bars, which is also the most common one.
Can white noise play all night for a baby?
The timer arrives set until morning, at a low level, and 30 min and 60 min are one tap away. The authors of that 2014 study advised the shortest time you can manage, so a short timer is the more cautious choice, while an all-night one keeps the background steady through a garbage truck at five. Which suits your child is a conversation for you and your pediatrician; this page is a player and not medical advice.
Will my baby become dependent on it?
A room with sound in it every night becomes the normal room, so a quiet one can feel strange for a few nights. That's a habit and not a harm, and it loosens more easily early than late. Drop the level a notch every few nights, then shorten the timer, then stop.
White, pink or green noise for a nursery?
They are the same kind of sound spread differently. White is a bright, even hiss. Pink is softer and rounder, and green sits in the middle and sounds a little like distant water. None of them is the correct one, so pick whichever you can run at a lower level and still stop noticing, because the level and the distance matter far more than the color.