Age-related changes in binaural processing: II. Behavioral findings.

In the preceding report in this journal, the authors presented evidence for an electrophysiologic correlate of impaired binaural processing or attention in elderly listeners. In the present experiment, the subjects tested in the earlier study were administered a Dichotic Digits Recognition task in which they were required, in separate sessions, to repeat all digits heard in both ears (channel capacity measure), or to report the digits in one ear while ignoring the digits in the opposite ear (selective attention measure). With both measures, older subjects performed significantly poorer than did younger subjects. Although similar age-related decrements in performance were observed with the behavioral and electrophysiologic tests, no significant correlations were found in the performances on the two types of tests. This suggests that, while both behavioral and electrophysiologic tests can reveal age-related decrements in binaural processing, they do not necessarily reflect the same underlying neural processes.