A new study has found that “sleep machines” used for infants can actually have the ability to damage a baby’s hearing. The devices use a constant sound, such as a heartbeat, “white noise” or a babbling brook, to help infants fall asleep and stay asleep. However, researchers have found that these machines can actually produce noise levels above what is recommended for workplace noise.
The study, published online today in Pediatrics, tested 14 sleep machines widely available in the US and Canada. All of them were able to surpass the noise 50 decibel noise limit recommended for hospital nurseries and 3 were able to surpass the 85 decibel level recommended for workplace noise if placed on the rail of the crib. Thirteen out of 14 machines were able to top 50 decibels even from across the room.
Hearing experts say that, given this information, parents should position the machine far away from the crib and have the volume on low. Dr. Blake Papsin, senior author on the paper and chief of otolaryngology, head and neck surgery at the Hospital for Sick Children in Toronto, Canada, notes that these precautions are not on the packaging of the devices.
Another concerning factor, according to Papsin, is that parenting websites encourage the use of these sleep machines all night and at a volume loud enough to overpower other noises that might be heard in the baby’s room. As a result, “some parents are probably overexposing their babies to noise,” he said. Papsin says he is skeptical about exposing developing infants to constant, monotonous noise for the entire night rather than letting them experience the sounds of their natural environment. He says that the brain pathways for hearing are still developing in babies, and animal studies have shown that prolonged exposure to white noise can change the way animals process sounds.
There is no evidence to show that sleep machines interfere with how infants develop, but Papsin is not the only expert who feels that it is an important thing to consider. Patti Martin, director of audiology and speech pathology at Arkansas Children’s Hospital in Little Rock, questioned “Is it a good thing to train infants to need steady noise to go to sleep?” Martin said that it’s possible this could make it difficult for some children to filter out everyday background noise. Papsin says that parents should consider trying a warm bath or a lullaby before buying a sleep machine.