The prevalence of central presbyacusis in a clinical population.

To evaluate the prevalence of central auditory disorder as a function of aging, we analyzed speech audiometric test results on 700 patients, 100 patients from each of seven half-decades beginning at age 50 years. In addition, we evaluated the extent to which prevalence estimates could be explained by the effect of hearing loss on measures of central auditory processing and the difference in prevalence of central presbyacusis between a clinical sample and a nonclinical sample. Results showed that the prevalence of central presbyacusis increased with age and that the highest prevalence was a striking 95 percent in the 80+ year age group. Results also showed that, even when degree of hearing loss and ability to perform the speech audiometric task were equated, the prevalence of central presbyacusis increased systematically with age. Finally, results showed that the prevalence was lower in the nonclinical sample than in the clinical sample at all ages, but that a substantial amount of central presbyacusis existed in the nonclinical subjects, especially in the oldest age groups.