Do sound restoration hearing protectors provide adequate attenuation for gunfire noise?
J Acoust Soc Am 2002 Nov; 112(5)(Part 2):2294
Sound restoration earmuffs have an electronics package installed in a passive earmuff shell or earplug body. The electronics package consists of a microphone placed on the outside of the ear cup or earplug and a limiting amplifier driving a loudspeaker placed inside the ear cup or the earplug. The devices are designed to provide unity gain or better to low-level signals and to shut off when sound exceeds a given level. The effects of several sound restoration earmuffs and two nonlinear orifice earplugs on gunfire for several different weapon types were analyzed. In general, the nature of the electronics packages was such that the studied devices provided the same attenuation when turned on as when turned off. However, as with passive devices, a single protector, be it by earplug or earmuff, appears to be inadequate for gunfire when more than just a few shots are fired. Sound restoration earmuffs are best used with a well-fitted earplug, since the electronics can compensate for both the insertion loss of the earmuff and the earplug. However, nonlinear orifice earplugs may not provide sufficient protection for extended sessions of target practice.
Hearing-level; Hearing-protection; Ear-protection; Ear-protectors; Noise-control; Noise-protection; Noise-shields; Electronic-devices; Sound-attenuation; Law-enforcement-workers; Police-officers; Impulse-noise
National Institute for Occupational Safety and Health, Hearing Loss Prevention Section, 4676 Columbia Parkway, MS C-27, Cincinnati, OH 45226-1998
Journal of the Acoustical Society of America