Perception of dichotic chords (free recall and directed recall), nonsense syllables (CVs), and three-pair digits was assessed on 24 musicians and 24 nonmusicians. On the dichotic-CV and dichotic-digit free-recall tasks, there was a significant right-ear advantage, but there were no group differences. With the dichotic-chords, free-recall condition, a significant left-ear advantage was observed but no group difference. For the dichotic-chords, directed-recall conditions, the musicians performed significantly better by 10 percent than the nonmusicians. Unexpectedly, for the dichotic chords, the 62-72 percent correct performances were better on the free-recall condition than the 42-55 percent performances on the directed-recall conditions. These differences between the two response modes were attributed to the difficulty of the dichotic-chord listening tasks and the probabilities associated with the closed-set response paradigms. The findings suggest that the dichotic-chord paradigm used in this study should not be included in clinical protocols used to assess auditory perceptual abilities.

Dichotic listening was evaluated in free-recall and directed-recall (pre-cued, post-cued) response conditions using interleaved one-, two-, and three-pair dichotic digit materials. In the free-recall condition, the subjects recalled in any order the digits presented. In the directed-recall condition, a response task was examined where subjects recalled all digits presented to the cued ear (pre- or post-cued) followed by the digits presented to the opposite (non-cued) ear. Thirty 20- to 29-year-old adults with normal hearing and 30 60- to 79-year-old adults with mild-to-moderate sensorineural hearing loss were evaluated. In all conditions, performance by the younger listeners was better than performance by the elderly listeners. As the difficulty of the dichotic digit task increased, recognition performance decreased. The recognition performance of elderly listeners was more affected by increases in the difficulty of the stimulus materials as compared to the younger listeners. In the free-recall condition, there was a right-ear advantage for both age groups. When instructional bias was imposed, the results favored the ear of instructed bias. The differences in recognition performance between young and elderly listeners likely reflect differences in the difficulty of the dichotic digit test conditions and variations in the demand on auditory memory.