Sound machines: Are they affecting your child's hearing?

A past study has revealed a link between commonly used noise machines and noise-induced hearing loss in infants. We talked to Le Bonheur Audiologist Tracy Ambrose to see what she had to say about this finding.

Many parenting resources currently encourage parents to use a sleep machine to block out ambient noise, like TV playing from the next room, for example. The thought behind this recommendation is that sudden noises will be masked by the sleep machine to allow the baby to get a good rest. They recommend playing these machines at levels equal to or louder than the volume of a baby’s cry (which averages 110 decibels). This level of exposure for more than a few minutes at a time far exceeds adult safety regulations mandated by OSHA (Occupational Safety and Health Administration).

Maximum acceptable noise exposure levels for adults are as follows:

85 Decibels (A weighted) = 8 hours allowed time exposure (without hearing protection)
88 Decibels = 4 hours
91 Decibels = 2 hours
94 Decibels = 1 hour
97 Decibels = 30 minutes
100 Decibels = 15 minutes
103 Decibels = 7.5 minutes
106 Decibels = less than 4 minutes
112 Decibels = less than 1 minute
115 Decibels = about 30 seconds

Children may be even more sensitive to noises due to the size of their ear canals.

To give you an idea of what these levels sound like, here are some common sounds in decibels:

  • Normal conversation = 60 Decibels
  • Vacuum cleaner = 60-85
  • Blender = 80-90
  • Lawn mower = 85-95
  • Rock concert = 110-120
  • Airplane taking off = 140
  • Fireworks (at 3 feet) = 162
  • Shot gun = 170

While parents may be using sound machines to give their baby a better night’s sleep, research actually indicates that background noise can cause sleep disturbances, as well as additional body responses, such as increased heart rate or apnea episodes.

More concerning yet is that research done on neonatal rats implies that white noise exposure during early development leads to distorted processing of auditory signals through the brain pathways. If this applies to humans, it could lead to speech and language development difficulties among other problems.

Here’s the bottom line. High levels of noise exposure over a long period of time is bad for a person’s hearing at any age, but by introducing these high levels of noise exposure during infancy, you can create a permanent hearing handicap for your child that could have adverse effects on their ability to communicate for the rest of his or her life. If you do use a sound machine, remember to:

  • place the sound source as far away from your baby as possible
  • turn the volume down as much as possible
  • limit the time of use

infant, sleep