Blast Overpressure Studies.
Abstract
To satisfy the Army's need for realistic safe limits for heavy weapons noise while wearing hearing protection, a 2-1/2 year study was undertaken. Using active duty military volunteers, 64 subjects established that the auditory system could be adequately protected with the RACAL muff from one to three exposures of the reverberant waveforms obtained from a rocket launcher out of an enclosure. Thus, nonauditory considerations set the exposure limits for this type of waveform. This research was accomplished under Task Order 1. Using 27 subjects, two types of nonlinear (increasing attenuation with level) hearing protection were evaluated using 6 to 100 exposures of a freefield waveform of 1.5-ms duration. With the limited number of subjects, neither plug was adequate to protect the auditory system from this type of waveform. Several subjects had a temporary threshold shift (TTS) of their hearing of more than 25 dB. The compressible foam plug did appear to provide adequate protection up to the auditory limits for this waveform. This research was accomplished under Task Order 4.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1998
- Accession Number
- ADA347634
Entities
People
- Daniel L Johnson
Organizations
- United States Army Aeromedical Research Lab