Hearing in the elderly--the Framingham cohort, 1983-1985: Part II. Prevalence of central auditory processing disorders.

The relation between central auditory processing disorders (CAPD) and age has been described in selected subjects. However, the prevalence of CAPD in the general population has not been established. We tested 1026, 64- to 93-yr-old members of the Framingham Heart Study cohort with Central Institute for the Deaf W-22 lists (CID W-22) in quiet, the Synthetic Sentence Identification test with ipsilateral competing message (SSI-ICM), and the Staggered Spondaic Word test. The presence or absence of CAPD could be established with at least one of three indices in 1018 subjects. The CID W-22 performance-intensity function rollover index was greater than 0.20 in 1.4% of 1009 subjects. The difference between maximum CID W-22 and SSI-ICM (0 dB message-to-competition ratio) scores was greater than 20% in 18.2% of 816 subjects. The Staggered Spondaic Word category was moderately, severely, over-corrected moderately, or over-corrected severely abnormal in 10.7% of 941 subjects (using 12-59-yr-olds' norms and adjusting scores when appropriate). Abnormal results on any one index occurred in 22.6% of the subjects. Thus, we conclude that the prevalence of CAPD in the elderly is less common than previous studies would suggest. Furthermore, although the rate of CAPD increased with age, age accounted for no more than 15% of the variability of any of the three indices. Therefore, its presence is dominated by factors other than chronological age.