Auditory characteristics of noise-exposed memberscrossing age-related groups()

OBJECTIVE: To report audiological characteristics in a group of noise-exposed crew members on board ships. METHODS AND MATERIALS: Clinical and audiological measurements including pure-tone thresholds, acoustic immittance results and tinnitus questionnaires were collected from both the ship crew members (study subjects) and their land based colleagues (controls). RESULTS: 1) Noise exposed crew members showed not only high frequency, but also low frequency hearing loss; 2) Hearing impairment increased with age, with 65.5% of crew members younger than 50 years showing normal hearing while only 14.9% of those older than 50 years had normal hearing; 3) hearing loss gradually increased with the extension of on board career time; and 4) Most study subjects reported high pitch tinnitus, significantly more than the control group although not significantly different among different age groups. CONCLUSION: Noise induced hearing impairment from working on board ships shows specific frequency and age characteristics. Understanding these characteristics is important for advancing relevant studies and for effective prevention of noise-induced hearing loss in ship crew members.