Infant sleep machines and hazardous sound pressure levels.
Level 5 - mechanism / opinion, no new human data
Laboratory bench acoustic testing without human clinical subjects
PubMed 24590753 · doi:10.1542/peds.2013-3617
What was done
Sound levels of 14 infant sleep machines were tested at maximum volume across three distances (30 cm, 100 cm, and 200 cm). Output measurements incorporated correction factors to account for the acoustic properties of a 6-month-old infant's ear canal.
What was found
At 30 cm on maximum volume, all 14 devices produced maximum sound levels >50 A-weighted dB (dBA), exceeding recommended hospital nursery limits. Three machines produced sound levels >85 dBA, exceeding adult occupational limits if played for >8 hours.
Why it matters
Commercially available infant sleep machines can output sound levels exceeding recommended nursery and occupational thresholds, presenting a risk of hearing loss if operated at maximum volume near an infant.
Limits
The study tested only 14 devices and evaluated only maximum volume settings. It did not measure real-world parental usage patterns, nursery room acoustics, or direct clinical hearing outcomes in infants.
Cited by
- context Research recommends setting sound machines below 40 decibels, especially when used for children's sleep.