Health and Nutrition Examination Survey of 1971-75: Part I. Ear and race effects in hearing.

The Health and Nutrition Examination Survey of 1971-75 contains unique hearing data because its design permits generalization to noninstitutionalized civilians in the continental United States. Air-conduction thresholds and their relationships to age, ear, gender, frequency, and race were examined in unscreened 25- to 74-year-olds. Although the observed effects of age, gender, and frequency were expected, three aspects of the results were remarkable. First, there was support for previous observations that older females have poorer low-frequency hearing. Second, there was an ear effect among white males who had poorer 2 and 4 kHz mean thresholds on the left at all ages. Third, there was a pattern of poorer mean thresholds for blacks that was particularly evident in comparisons between black and white females.