Auditory characteristics of noise-exposed memberscrossing age-related groups

To report audiological characteristics in a group of noise-exposed crew members on board ships. 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). 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. 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.