[Comparison of intonation production in cochlear-implanted children and normal hearing children]

Due to defects of auditory feedback, children with hearing loss have inappropriate speech intonation. Consistently, results of previous studies have shown that cochlear implanted children have some difficulties in their intonation. Intonation shows the type of the sentence which can be statement or question sentences. The purpose of this study was comparison of speech intonation in cochlear-implanted children and normal hearing children. The present study was performed on 25 cochlear-implanted children and 50 normal hearing children. Different pictures were shown to the subjects and they said statement and question sentences. All sentences were heard by eight speech therapists and perceptually judged. Using praat software mean base frequency and pitch alterations were measured. In cochlear-implanted group, mean speech base frequency was higher and mean pitch alteration was lower than the control group. Mean experts' scores in cochlear-implanted group were lower than the control group. Differences in all three variables were statistically significant [p<0.05]. There was a significant direct correlation between duration of time that the children had cochlear implant and perceptual judgment scores [p<0.05]. According to the results, cochlear implant prosthesis has limited efficacy in improving speech intonation; although their ability to produce speech intonation improves by increasing duration of the time that children have cochlear implant. Thus speech therapists should consider intervening on speech intonation in treatment program of cochlear-implanted children.