We conducted a case-control study in 100 cases who had Alzheimer's-type dementia and
100 age-, sex-, and education-matched, nondemented controls to evaluate the hypothesis
that hearing impairment contributes to cognitive dysfunction in older adults. The prevalence
of a hearing loss of 30 dB or greater was significantly higher in cases than in controls (odds
ratio, 2.0; 95% confidence interval, 1.2 to 3.4), even when adjusted for potentially
confounding variables. In addition, we observed a dose-response relationship in which …