Infant sleep machines are designed to generate background noise to aid babies in sleeping soundly. However, a new study has found that these devices can damage their hearing. The findings were published online on May 3 in the journal Pediatrics by researchers at the University of Toronto (Toronto, Canada) and the Hospital for Sick Children (Toronto, Canada).
The study authors note that infant sleep machines (ISMs) produce ambient noise (background noise) or noise to mask other sounds in an infant’s room with the aim of increasing uninterrupted sleep. They noted that the consistent use of these devices raises concerns for increasing an infant’s risk of noise-induced hearing loss. Therefore, they conducted a study to determine the maximum output levels of these sleep machines.
The investigators measured the sound levels of 14 infant sleep machines played at maximum volume; measurements were made at 30 cm (12 in), 100 cm (40 in), and 200 cm (80 in) from the machine. Correction factors were applied to account for a six-month-old infant’s ear canal. The researchers found that maximum sound levels at 30 cm were higher than 50 decibels for all the machines; thus, they all exceeded the current recommended noise limit for infants in hospital nurseries. In addition, three devices produced output levels higher than 85 decibels. Playing a sleep machine at these levels for more than eight hours, exceeds current occupational limits for accumulated noise exposure in adults; therefore, it risks noise-induced hearing loss.
The authors concluded that infant sleep machines are capable of producing output sound pressure levels that may be damaging to infant hearing and auditory development.
Take home message:
If you have one of these machines in your child’s nursery, place it a distance away—NOT in the child’s crib. Do not crank up the volume. Also, listen to the device at the distance it will be from the child and ensure that it is at a low level.