When I think of hearing loss, I typically think of an elderly neighbor of mine that wears hearing aids. It has been only recently that we have been hearing more about hearing loss in teenagers. Preventable hearing loss.
Hearing loss from noise can be from sudden loud noises like an explosion or it can be from prolonged exposure to loud noises. The noise affects our hearing through changes in the hair cells of the cochlea. The word cochlea is derived from the Latin word for snail shell and it looks like a coiled sea shell in the middle of our ear. The cochlea is filled with a watery substance that vibrates in the presence of sound, this triggers hair cells within the cochlea which in turn convert motion to an electric impulse that is then sent to the brain for interpretation.
Recent estimates says that 1 in 5 adolescents in the USA will have permanent hearing loss. Noise induced hearing loss is preventable! There are lots of sources of dangerously loud noise: shooting firearms, concerts, car races…but the most common threat to our teenagers is the earphones that up to 90% of teenagers use. The threat with the earphones comes from not only the level of noise but the prolonged usage.
Hearing loss is the not the only result of damage from noise. Tinnitus (abnormal ringing in the ear) and hyperacusis (abnormal perception of loudness) and diplacusis (abnormal perception of pitch) can all be a result of noise exposure.
What are some general guidelines for limits of exposure according to the National Institute for Occupational Safety and Health?
Loud Rock Concert 115 db 30 seconds
Car Horn/Leaf Blower 110 dB 90 seconds
Portable music player 105 dB 5 minutes
(highest level)
Motorcycle/Hair dryer 95 dB 45 minutes
Lawn Mower 90 dB 2.5 hours
Portable music player 80 dB no limit
(comfortable level)
For more information on hearing loss, see the website Noisy Planet from the National Institute of Health.
