A laboratory simulation of selected in-field influences on hearing protector performance.
Proceedings of the Human Factors Society 33rd Annual Meeting, October 16-20, 1989, Denver, Colorado. Santa Monica, CA: Human Factors Society, 1989 Jan; 2:946-950
A study of the influence of work related factors on hearing protector performance was conducted. The study group consisted of 40 paid volunteers (20 males), 19 to 35 years old, with normal hearing. The subjects wore foam cushion earmuffs, slow recovery foam or flanged polymer earplugs, or an earmuff plus foam earplug combination for 2 hours during which they performed simulated job tasks that involved body and jaw motion while being exposed to 70 decibel-A pink noise. The hearing protectors were fit either by the subjects themselves or by a trained experimenter. The ability of the hearing protectors to attenuate the noise was evaluated by measuring occluded thresholds at 125, 250, 500, 1000, 2000, 3150, 4000, 6300, and 8000 hertz before and after 1 and 2 hours of exposure. Unoccluded thresholds were measured after exposure ended. The ability of all hearing protectors to attenuate noise decreased with exposure time. The slow recovery foam earplug showed the least degradation in attenuation. Attenuation was generally poorer when the subjects fit the hearing protectors than when the experimenter fit them. The authors conclude that the performance of hearing protectors is seriously degraded if the worker initially fits them poorly and makes vigorous movements. The slow recovery foam earplug appears to be more resistant to noise attenuation loss resulting from body movements than other protectors. Laboratory hearing protector tests should be conducted under more realistic conditions.
NIOSH-Grant; Noise-exposure; Hearing-protection; Hearing-tests; Hearing-threshold; Humans; Laboratory-testing; Ear-protectors
Indus Engr and Operations Res Virginia Polytechnic Institute Blacksburg, VA Blacksburg, VA 24061
Proceedings of the Human Factors Society 33rd Annual Meeting, October 16-20, 1989, Denver, Colorado
Virginia Polytechnic Inst and St Univ, Blacksburg, Virginia