Accession Number : ADA291604

Title :   Actual Effectiveness of Hearing Protection in High Level Impulse Noise.

Corporate Author : ARMY AEROMEDICAL RESEARCH LAB FORT RUCKER AL

Personal Author(s) : Patterson, James H., Jr. ; Johnson, Daniel L.

PDF Url : ADA291604

Report Date : AUG 1994

Pagination or Media Count : 19

Abstract : Current exposure limits for high intensity impulse noise contain factors for hearing protection which are based on very limited data. Recent studies in the U.S. and in France have provided new insights into the protection afforded by hearing protective devices. For impulses with an A-duration of approximately 3.0 ms, protection was found to be adequate for peak pressures up to 190 dB SPL for 6 impulses and 187 dB for 100 impulses. Protection was found to be adequate for 6 impulses with an A-duration of approximately 0.8 ms up to 196 dB SPL. For this A-duration, protection was adequate for 12 impulses up to 190 dB SPL and for 50 and 100 impulses at 187 dB SPL. The hearing protectors used in these studies were earmuffs with perforations in the cushions which provided essentially attenuation below 500 Hz. In a series of French studies, hearing protection was found be adequate for impulses produced by a variety of weapons with peak pressures ranging from 165 dB SPL to 180 dB SPL. These included small arms with A-durations less than 1.0 artillery with A-durations of approximately 3.0 ms and other weapons with durations between these extremes. A variety of insert hearing protectors (earplugs) was used in these studies. (AN)

Descriptors :   *IMPULSE NOISE, *HEARING, *EAR PROTECTORS, PEAK VALUES, MILITARY PERSONNEL, EXPERIMENTAL DATA, COMPARISON, EXPLOSIONS, LIMITATIONS, SMALL ARMS, HIGH INTENSITY, ACOUSTIC ATTENUATION, NOISE REDUCTION, EXPOSURE(PHYSIOLOGY), SOUND PRESSURE, BACKGROUND NOISE.

Subject Categories : Acoustics
      Protective Equipment
      Anatomy and Physiology
      Noise Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE