Noise Induced Hearing Loss And Technology Use
This is a guest post by of Dr. Marcella Roper Bothwell, MD, FAAP of the American Academy of Otolaryngology-Head and Neck Surgery about their recent survey. I was contacted by them to particpate in a conference call - and then I asked them to write a guess post about hearing loss and use of technology. Here it is.
If you worry about your kids listening to their iPod at full volume or watching their portable DVD player with headphones while you hear the entire dialogue, you are not alone. A recent survey by the American Academy of Otolaryngology – Head and Neck Surgery found that four in five Americans are concerned about hearing loss due to ear buds and that hearing loss is a top medical concern for parents. And with good reason: Three million children under the age of 18 have some form of hearing loss, and nationwide, more than 10 million Americans suffer from noise-induced hearing loss.
Hearing is the brain’s interpretation of sound or sound pressure from the outside world. Loss of hearing can be divided into two categories: conductive and sensori-neural hearing loss. Sound is ‘conducted’ to the nerve for perception. Any abnormality in the external ear, canal, tympanic membrane, or middle ear bones, or fluid in the middle ear can cause conductive hearing loss. This type of hearing loss can sometimes be reversed.
Sensori-neural hearing loss occurs when sound comes through these organs and damages the cochlea, the “nerve” organ for hearing. The cochlea receives the sound signal and transforms it to neural input or electrical impulses to the brain. When these nerves are damaged by exposure to loud sound, hearing loss can result. Senori-neural (or sound-induced) hearing loss is not reversible, which is all the more reason why parents should do all they can to prevent this type of hearing loss.
The Occupational Safety Administration requires hearing protection if a person is exposed to 85 decibels (dB) of sound for 8 or more hours. If you were to go into a closed room and turn on a stereo, but can easily hear someone talking, that’s around 85 dB. Because dBs are log rhythmic, not linear, 95 dB can cause hearing damage within 4 hours. At 110 dB, a range easily attainable through a personal music player, hearing damage can happen in an hour or less.
You can help ensure that your child is using personal music players or other devices with headphones safely.
When buying new devices, look for those with the ability to control the volume limit externally and set the maximum at 60-70% of the maximum volume. For example, on an iPod Classic, click Settings, then Volume Limit. Use the Click Wheel to adjust the maximum volume down. Then click the Center button and set a four digit passcode. Your kids won’t be able to crank their iPods up to full volume, which can reach levels up to 115 dB (louder than the noise from a powersaw).
Be aware of ambient noise which may be as high as 90 dB in a subway. To hear over these noises, it would be natural to turn up the volume by 10 dB, resulting in 100 dB delivered to your ear which can cause damage to your ear in an hour or less. Noise isolating and / or noise cancelling ear phones can be of help but does not replace sensibility in listening.
Have your kids use ear plugs or ear muffs when they’re involved in loud activities, including musical performances, mowing the lawn, etc.
Talk to your kids about noise-induced hearing loss. These are the only two ears they’ve got. Empower them to protect their hearing. There are no quick fixes for noise-induced hearing loss. We’d all hate to have kids be forced to turn in their headphones for hearing aids.