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).