Baby white noise machine:
how loud is too loud?

What the study found

Researchers from the Hospital for Sick Children in Toronto (Hugh and colleagues) published measurements of 14 commercially available infant sleep machines at maximum volume in Pediatrics in 2014.

• The recommended limit for hospital nurseries is 50 dBA averaged over an hour. All but one machine exceeded it at all three distances.
• Three exceeded 85 dBA at 30 cm, the level used as an 8-hour workplace limit for adults.

The researchers’ advice

1. As far away as possible — never in or on the crib.
2. Lowest volume that works.
3. Run it briefly, until the baby is asleep, ideally with a timer.

Doubling the distance cuts the level by roughly 6 dB, so where you put it can matter more than the volume button.

Measuring at head height

• Place the phone where the baby’s head would be (with the baby elsewhere).
• Run the machine at your usual volume for one to two minutes.
• Turn it off and measure the room on its own to see the difference.

Phone readings are not A-weighted, so bass-heavy sounds such as brown noise can read higher than dBA. Use comparisons like "moving it cut 5 dB". For choosing a noise color, see white, pink and brown noise.

Checking with the app

1

Turn on the machine and measure

In Focus Noise Meter, tap Start. Check Avg after one to two minutes.

2

Move it, measure again, compare

Measure again with the machine further away and both sessions sit side by side in Records. The difference in average shows the effect of placement.

FAQ

Related guides

• Choosing a home office room by measuring noise3 rooms × 3 times · windows open and shut · set up for video calls
• Why phone decibel apps differ from sound level metersA-weighting · mic sensitivity and auto gain · averaging · what ±2 dB means
• How to check for noise when viewing an apartment or houseWindows shut and open · roads, elevators, AC units · come back at night
• All Focus Noise Meter guides10 guides in one place