Dichotic Listening in Hearing-Impaired Children

Ear asymmetry for dichotic digits was used in an attempt to estimate speech laterality in 19 children with impaired hearing and 19 with normal hearing. Sequences of digits were also presented monaurally. The normal-hearing group was significantly superior to the hearing-impaired in the recall of both monaural and dichotic digits. No ear advantage was observed for either group on the monaural test. Right-ear dichotic scores were significantly superior for the normal-hearing group, but intersubject variability resulted in a nonsignificant right-ear trend for the hearing-impaired group, with individuals showing marked right- or left-ear advantage. No correlation was found between degree of ear asymmetry on the dichotic test and vocabulary scores for hearing-impaired subjects. Both members of a dichotic pair were rarely reported by hearing-impaired subjects, with one digit apparently masking or suppressing the other. It was concluded that speech lateralization could not safely be inferred from dichotic digit scores of hearing-impaired children.