Temporal-phonemic processing skills in adult stutterers and nonstutterers.

The purpose of this study was to investigate the hypothesis that stuttering is related to a dysfunction in auditory temporal processing. The performance of 20 adult male stutterers and 20 matched nonstutterers was studied using two auditory processing tasks. The subjects listened to stimuli with differential onset asynchronies during temporal order judgment (TOJ) and dichotic listening tasks. Stutterers and nonstutterers were not significantly different at judging which ear received the stimulation first (TOJ task) at varying stimulus onset asynchronies (SOAs). During the dichotic listening task, stutterers made significantly fewer double-correct responses (correct report for both stimuli in a dichotic pair) than nonstutterers. The stuttering subjects correctly classified one of the syllables in a pair (single-correct response) more frequently than normal controls on the dichotic listening task. These findings suggest that SOAs as a temporal parameter do not differentiate the performance of the two groups. The more difficult auditory processing task (dichotic identification) showed a significant difference in the performance of the stutterers versus nonstutterers.