Auditory stroop effects in children with hearing impairment.

The accurate perception of speech involves the processing of multidimensional information. The aim of this study was to determine the influence of the semantic dimension on the processing of the auditory dimension of speech by children with hearing impairment. The processing interactions characterizing the semantic and auditory dimensions were assessed with a pediatric auditory Stroop task. The subjects, 20 children with hearing impairment and 60 children with normal hearing, were instructed to attend selectively to the voice-gender of speech targets while ignoring the semantic content. The type of target was manipulated to represent conflicting, neutral, and congruent relations between dimensions (e.g., the male voice saying "Mommy," "ice cream," or "Daddy" respectively). The normal-hearing listeners could not ignore the irrelevant semantic content. Instead, reaction times were slower to the conflict targets (Stroop interference) and faster to the congruent targets (Stroop congruency). The subjects with hearing impairment showed prominent Stroop congruency, but minimal Stroop interference. Reduced Stroop interference was not associated with chronological age, a speed-accuracy tradeoff, a non-neutral baseline, or relatively poorer discriminability of the word input. The present results suggest that the voice-gender and semantic dimensions of speech were not processed independently by these children, either those with or those without hearing loss. However, the to-be-ignored semantic dimension exerted a less consistent influence on the processing of the voice-gender dimension in the presence of childhood hearing loss. The overall pattern of results suggests that speech processing by children with hearing impairment is carried out in a less stimulus-bound manner.