Prolonged auditory processing time in the elderly: evidence from a backward recognition-masking paradigm.

Abstract

The rate of processing pure-tone stimuli was measured in 10 elderly subjects and 10 young controls using an auditory backward recognition-masking paradigm. Experimental trials consisted of the presentation of either a 770- or 870-Hz target stimulus (TS) followed by an 820-Hz masking stimulus (MS), separated by a variable silent intertone interval (ITI). For both groups, the mean percent correct recognition scores for TS identification improved systematically with increases in ITIs, reaching an asymptote followed by an apparent plateau. The mean recognition scores at each ITI were lower for the elderly subjects than for the controls; however, equivalence between groups was observed at prolonged ITIs. The elderly group's mean asymptote was observed at a longer ITI (360 ms) relative to that of the controls (248 ms), a statistically significant difference. The findings suggest an age-associated slowing in auditory processing time.