Thursday, April 21, 2005
Noise, Noise Noise, Noise - Protect the Ears
It's easier than you might think to develop noise-induced hearing loss. Even short brief very loud noises can cause cause permanent damage to delicate hair cells. The danger zone is about 80 dB, but even lower levels can cause damage if its continuous. Warning signs include temporary shifts in hearing, ringing or buzzing in the ear, difficulty hearing in noise, and symptoms of hypersensitivity along with hyposensitivity (when one area of frequency gets lost, neighboring frequencies may become more sensitive).
The pictures below are from Chang and Merzenich, showing how white noise in young rats caused disorganized patterns in the auditory cortex. They also found that providing low level structured sounds as adults corrected some of the abnormality, so look for more interesting auditory training approaches for humans in the future.
1/3 of Americans with hearing loss have their loss from noise. Some rock bands have caught on (Quiet Concert), but there are also obvious dangers from listening to music on headphones (at level 5, 100 dB - can damage after just 15 minutes per day), Barbie CD player on high(84-114 dB), NICUs (neonatal ICUS) 80 dB, Game arcades 115 dB. The entertainment industry needs to jump on the wagon too.
Chang and Merzenich paper
Noise-induced hearing loss
Noise Rewires the Brain
Loud rock music, Baby Boomers, Hearing Aids
CBC News: Noisy toys damaging kids' hearing
Noise-Induced Injury in NICU Kids