Evaluation of level-dependent hearing protection devices for use with impulsive noises.
NHCA Spectrum 2004 Feb; 21(Suppl 1):24
As a part of a NIOSH Health Hazard Evaluation of law-enforcement personnel, the attenuation of several types of earplugs and earmuffs was measured in response to impulse noise produced by small-arms gunfire. The protectors were measured on a mannequin built by the Institute de Saint Louis for increased acoustic isolation of flanking pathways to the microphone. The earplugs demonstrated a range of peak reduction between 10 and 28 dB while the earmuffs ranged from 25 to 33 dB peak sound pressure level. The slopes of the peak reduction with peak level for most earplugs exhibited a slope of 0.2 dB/dB while earmuffs tended to have a slope of 0.5 dB/dB. Finally, the risk of hearing loss was estimated with the Auditory Hazard Assessment Algorithm for Humans (AHAAH model) and demonstrated a range of Auditory Hazard Units from 450 to 10 for impulses recorded underneath hearing protectors. AHUs could be reliably be predicted for small-arms fire from the peak level reduction.
Hearing; Hearing-conservation; Hearing-protection; Impulse-noise; Noise; Law-enforcement; Law-enforcement-workers; Hearing-loss; Noise-induced-hearing-loss; Risk-factors; Risk-analysis; Auditory-system
Conference/Symposia Proceedings; Abstract