A Field Investigation of Noise Reduction Afforded by Insert-Type Hearing Protectors (Final Report).
Edwards-RG; Hauser-WP; Moiseev-NA; Broderson-AB; Green-WW
NIOSH 1977 Jun:216 pages
A total of 840 attenuation measurements were made using 168 subjects and an audiometric van at six factory sites to determine effective noise reduction levels for inserted hearing protectors. Earplug design, company usage policy, worker activity, noise levels, and the effect of test sequence were correlated to noise attenuation. Protection ranged from 6 decibels (dB) at 125 hertz (Hz) to 20dB at 3,150Hz. These values were only 35 to 50 percent of the potential attenuation. No correlations were found between protection and noise levels, earplug design, or company policy, but test sequence learning occurred and the more physically active workers received better protection at 250 and 2,000Hz. The authors conclude that the lack of protection afforded by the earplug was due to improper fit and usage. Different types of hearing protectors and reasons for equipment misuse also should be investigated. Laboratory attenuation values should be derated by 60 percent to rate workplace performance accurately.
NIOSH-Contract; Contract-210-76-0139; Industrial-workers; Noise-pollution; Noise-control; Ear-protectors; Hearing-protection; Personal-protective-equipment; Noise-measurement;
Control Technology and Personal Protective Equipment; Research Tools and Approaches;
NIOSH Cincinnati, Ohio, 216 pages, 10 references