Hearing levels of aerospace workers as affected by duration of employment

Studies of the audiograms of a sample of male aerospace workers to establish the relationship between hearing level and occupational exposure indicate that hearing levels at 4000 Hz of the sample are essentially the same as the general U. S. male population under age 45 but show a greater loss over age 45. Partial correlation studies relating hearing level changes to duration of employment, with age effects held constant, attribute this difference to factors other than occupational exposure. The correlation studies of the overall sample show a slight trend for increasing loss with longer durations of employment. The net effect is of no practical significance. Detailed age group correlation studies indicate that this age-related change occurs primarily in the under age 35 group, a factor of significance to hearing conservation activities.