The ABCs of Protecting our Children’s Hearing

February 9, 2012
The ABCs of Protecting our Children’s Hearing When thinking about hearing loss resulting from exposure to loud noise, one may often think this only concerns workers in industrial settings.

However, our children’s hearing may also be at risk if they are exposed to loud sounds or noises. This article briefly presents a few points that parents should be aware of regarding their children’s hearing and how noise may affect it.

What happens when the ear is exposed to high levels of noise?

A noise-induced hearing loss may occur whenever the ear is exposed to either a steady high level of noise (or sounds) for a long period of time (the risk typically starts at around 85 dB A based on 8 hours/day of exposure), or to a very intense noise (typically over 110 dB A) for a shorter period of time.

The damage happens inside the inner ear. The hair cells are destroyed as a result of the high level of sound exposure. Once the hair cells are destroyed the process is irreversible (meaning these cells are never going to recover or repair themselves). This loss of cells in the inner ear deprives the ear of hearing sounds normally and may cause difficulty hearing and understanding speech. Tinnitus (“ringing” in the ears) is also very often reported with noise-induced hearing loss. If the hearing loss occurs in the early years, it may impede the child’s speech and language development. Later on in school settings it may cause difficulties in understanding speech (especially from a distance) and may affect the child’s academic performance, social interactions and so on.

What are the risk factors?

The risk of developing hearing loss from high sound level exposure mainly depends on two factors: how loud is the sound (or noise) and how long have you been exposed to it. To get a better idea of what can be damaging to your hearing, here is a scale showing the decibel level of different day-to-day noises as a function of the risk.

It is important to mention that the dB scale is logarithmic. This means that for every 3 dB increase in the actual intensity of a sound, the sound is perceived as being twice as loud. For example, if you measure the level of a hair dryer, you will record a reading of 70 dB. If you add another hair dryer, you will subjectively feel the sound is twice as loud. However, the reading on the sound level meter is going to be 73 dB NOT 140 dB.

The ABCs of Protecting our Children’s Hearing

REFERENCES
National Institute on Deafness and Other Communication Disorders, National Institute of Health, Bethesda, USA.
Mémoire de l’Ordre des Orthophonistes et Audiologistes du Québec. Mémoire présenté dans le cadre de la consultation publique sur les véhicules hors route (juin 2005).