Efficacy of hearing-conservation programs in the mining industry

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:7194383

Dechant, D L

In a laboratory study, 20 young, healthy males with normal hearing were exposed to mine-drilling noise at a level of 110 dB(A). Exposures were of a two-hour duration and were repeated on five consecutive days. At all times during exposures, participants wore foam-insert protectors with a noise-reduction rating of 35dB. The audiometric threshold of participants were monitored prior to and immediately following exposures. Results showed substantial TTS development at all frequencies despite hearing conservation measures which were, in theory, thoroughly protective for the exposure conditions in question. Mean TTS ranged from 1.3 to 6.5 dB, with the largest mean value occurring at 4000 to 8000 Hz. In a field study, audiometric thresholds of 11 miners were monitored before and after routine 8-hour work shifts. Exposures were to a variety of mining noise sources and were variable in level and duration. Foam-insert protectors were worn by participants during all exposure periods. Results indicated that TTS had developed in the field study group at all frequencies. Mean shift severity ranged from 0.1 dB to 2.8 dB. These acuity decreases were not of sufficient magnitude as to have the high significance noted in the laboratory study. However, shifts in the higher frequencies were sizable enough to prevent drawing of firm conclusions.

• Research Organization: Colorado State Univ., Fort Collins (USA)
• OSTI ID: 7194383
• Country of Publication: United States
• Language: English

Related Subjects

560400* -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AUDITORY ORGANS
BODY
CLOTHING
DATA ANALYSIS
FIELD TESTS
FREQUENCY DEPENDENCE
MINING
NOISE POLLUTION
ORGANS
POLLUTION
PROTECTIVE CLOTHING
SENSE ORGANS
TESTING