Hearing acuity in professional divers.

Pure tone audiograms and relevant history were recorded in 164 professional divers aged 19 to 66 yr, mean 30.9. A close correlation exists between hearing impairment and increasing age, increasing diving experience, and acoustic trauma. A statistically significant elevation (P = 0.01) of the high-frequency hearing threshold is demonstrated in smokers as compared to those who had never smoked. The divers' hearing threshold was elevated in the high frequencies in all age groups as compared to ISO normality curves. It was, however, lower than that of a Norwegian standard population at a young age, but in their fourth decade of life, the divers' high frequency hearing was at the same level as that of the standard population. We conclude that professional diving may cause a more rapid deterioration of high-frequency hearing than seen in a standard population and that smoking may be an additional hazard to high-frequency hearing.