What new parent doesn’t want a good night’s sleep? White noise machines, also called sleep machines, are popular items in a nursery. These machines offer a variety of noises, ranging from white noise, to a heartbeat, to nature sounds, in order to help babies fall asleep. A new study published online by the journal Pediatrics found that these machines may pose a hearing risk for infants.
The U.S. National Institute for Occupational Safety and Health currently recommends that the noise level for an eight-hour period for adults should be limited to 85 decibels. The current recommendation for young children in hospitals is no more than 50 decibels averaged over an hour.
Fourteen different sleep machines were tested in the study. When placed in or next to the crib, all of the machines tested were able to produce sound that exceeded the 50 decibel recommendation. Three of the machines produced noise over 85 decibels when placed 30 centimeters away. At 200 centimeters away, all but one sleep machine produced noise greater than 50 decibels.
These levels show that using sleep machines may put infants in danger of hearing loss, especially when used all night. Dr. Blake Papsin, chief otolaryngologist at the Hospital for Sick Children in Toronto and chief author of the study said, “Completely removing all informational content at a loud, potentially damaging level is the worst.” This is because an infant’s brain is learning about sounds, even when asleep. Sleep machines used all night are robbing infants of a chance to differentiate between different sounds.
Lisa L. Hunter, scientific director of research in the division of audiology at Cincinnati Children’s Hospital, explained, “If you’ve conditioned them to white noise, there’s every indication that they might not be as responsive as they otherwise should be to soft speech.”
The study does not include the specific brands that were used, because Dr. Papsin wants to start the conversation that all of the sleep machines available are capable of causing hearing damage if they are used incorrectly.
Dr. Papsin decided to do the study after hearing a sleep machine parents brought to the hospital, which sounded as loud as a car wash.
The use of sleep machines is advised in a variety of parenting books and websites. Many of these machines come with limited instructions or even without any instructions at all.
The study recommends that manufacturers include instructions on how to use the device properly. They also recommend that manufacturers set a limit to the level of sound that the machines are capable of producing.
The authors of the study are not suggesting for parents to discontinue using sleep machines, but rather to use them cautiously. Recommendations include using them at a low volume setting, placing them far away from the infant’s crib, and turning them off once the infant is asleep, which will cut down on the amount of time the infant is exposed to the noise.
Following the recommendations will help parents to be decrease the risk of hearing loss in infants from sleep machines.
By Ashley Campbell