Dichotic word recognition in older adults

The present study was an examination of dichotic word recognition abilities in older adult listeners. Dichotic word recognition, using the NU-6 monosyllabic words from the VACD Speech Recognition and Identification Materials 1.1 (1991), was evaluated in three response conditions: free recall, directed right and directed left. Participants included a group of young adults with normal hearing (19–30 years), and two groups of older adults (60–69 years and 70–79 years, respectively) with mild to moderately-severe sensorineural hearing loss. Dichotic word recognition performance was best for the young adult listeners and decreased with each older age group. In the free recall condition, right ear advantages were observed in all age groups. The right ear advantages observed in the older adult age groups were larger than those for the young adult group and reflected a greater deficit in performance on dichotic words presented to the left ear. Ear advantages in the directed recall conditions favored the directed ear in all age groups. Left ear advantages in the directed left condition were considerably smaller than the right ear advantages in the directed right condition for both older adult age groups. A small subset of older adult listeners exhibited a left ear deficit in both free recall and directed recall conditions, which was attributed primarily to a compromise in auditory processing. Overall, the results of the present study support the hypothesis of an age-related disadvantage in performance for dichotic stimuli presented to the left ear across response conditions.