Recognition of Randomly Presented One-, Two-, and Three-Pair Dichotic Digits by Children and Young Adults

Purpose: To establish normative data for children and to characterize developmental differences in performance with the free recall version of the Randomized Dichotic Digits Test.

Research Design: Group comparison of behavioral data derived from administration of the Randomized Dichotic Digits Test.

Study Sample: Children from 10 to 18 years of age (167) and young adults from 19 to 28 years of age (50).

Results: Performance improved with age across all types of digit pairs, especially in the left ear, leading to smaller interaural asymmetries among older participants. A left-ear advantage was produced by 39 subjects (18%), only two of whom were left-handed. Normative data are reported for right and left ear scores and for interaural asymmetry (percent correct difference between the two ears) under one-, two-, and three-pair conditions of the test and for interaural asymmetry across the entire test. A unilateral deficit was identified in children (15.5%) and young adults (12%) for the left ear and in children (11.3%) and young adults (6%) for the right ear. A bilateral deficit was also identified in children (6.5%) and young adults (6%).

Conclusions: This test may be useful as part of the clinical battery for identifying binaural integration weaknesses and referring individuals for auditory rehabilitation for interaural asymmetry (ARIA).

Key Words

Adolescents - auditory processing - children - development - dichotic listening - interaural asymmetry - left-ear deficit - maturation