Hearing Protection of Earmuffs Worn over Eyeglasses
AIR FORCE AEROSPACE MEDICAL RESEARCH LAB WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
The hearing protection ordinarily provided by earmuffs is reduced when worn by persons who also wear eyeglasses because sound enters the device through air leaks around the eyeglass temple - earmuff cushion interface. This study examined the acoustic fit of different earmuff protectors and various types of eyeglass frames found in a population, measured the loss of attenuation due to programmed air leaks and measured differences in earmuff protection for subjects while wearing and not wearing eyeglasses. Results demonstrated that earmuffs worn over eyeglasses lose from 1 dB to 10 dB of attenuation at individual frequencies. The amount of loss is related to type of earmuff, type of eyeglasses as well as frequency of the sound. Two remedial approaches were identified as authorizing for use by eyeglass wearers only earmuffs that demonstrate by test satisfactory sound protection with eyeglasses, and the use of an insert or pad at the eyeglass temple - earmuff cushion interface to minimize and eliminate the acoustic leak.
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