Accession Number:

ADA224108

Title:

Nonauditory Injury Threshold for Repeated Intense Freefield Impulse Noise

Descriptive Note:

Final rept. 1 Jan 1980-1 Jan 1989

Corporate Author:

WALTER REED ARMY INST OF RESEARCH WASHINGTON DC

Report Date:

1990-03-01

Pagination or Media Count:

8.0

Abstract:

Exposure to impulse noise is an important occupational health concern. The risk of injury to auditory structures is well recognized and provides the cornerstone for present safety standards. For freefield impulse noise, nonauditory injury is dependent on peak pressure positive phase duration or impulse, and number of exposures. Trivial laryngeal petechiae are shown to precede nonauditory injury to more critical organs i.e. pulmonary and gastrointestinal systems. This study identifies the critical impulse noise thresholds causing trivial laryngeal petechial changes resulting from exposure to 5, 25, and 100 repetitions of specific levels of impulse noise. Because of anatomical differences, sheep should be slightly more susceptible to impulse noise laryngeal petechial changes than man therefore, it seems reasonable to set the absolute limits for human occupational exposure levels below those causing laryngeal petechiae in sheep for persons wearing adequate hearing protection. This study does not address human auditory injury that may occur above or below these exposure limits even with proper hearing protection. Keywords Blast overpressure limits Nonauditor injury Occupational medicine. Reprints.

Subject Categories:

  • Medicine and Medical Research
  • Environmental Health and Safety

Distribution Statement:

APPROVED FOR PUBLIC RELEASE