Attenuation measurements of passive linear and nonlinear hearing protectors for impulse noise.
J Acoust Soc Am 2003 Apr; 113(4):2195
As a part of a NIOSH Health Hazard Evaluation of law-enforcement personnel, the attenuation of several types of earplugs were measured in response to impulse noise produced by small-arms gunfire. The earplugs were primarily flanged premolded plugs produced by EAR/Aearo and Bilsom/Baccou-Dalloz. Measurements for the North Sonic Ear Valve, EAR Classic earplugs, and EAR Ultra 9000 passive nonlinear ear muff were conducted. The EAR premolded earplugs were the Combat Arms passive linear and nonlinear, HiFi and Ultratech earplugs. The Bilsom devices were the 555, 655 NST, and 655 ISL earplugs. The Combat Arms and 655 ISL earplugs both utilize a cartridge developed by the French German Research Institute de Saint Louis that provides nonlinear attenuation. The peak reduction of these devices ranged between 10 and 28 dB. The slope of peak reduction with peak level for the Ultra9000 device was about 0.5 dB/dB, while the slopes for most earplugs were about 0.1 to 0.3 dB/dB for weapons impulses between 159- and 170-dB peak level. The peak reductions ranged from 6 dB for the North Ear valve to 30 dB for the EAR Classic foam earplug.
Hearing-level; Hearing-loss; Hearing-acuity; Health-surveys; Age-factors; Age-groups; Information-retrieval-systems; Physical-examination; Racial-factors; Sex-factors; Audiological-testing; Audiometry
William J. Murphy, NIOSH, Hearing Loss Prevention Section, 4676 Columbia Pkwy., M.S. C-27, Cincinnati, OH 45226-1998
Journal of the Acoustical Society of America