Sentence stress in children with dysarthria and cerebral palsy

Purpose: This study aimed to advance our understanding of how children with dysarthria and cerebral palsy (CP) realise sentence stress acoustically, and how well listeners could identify the position of the stressed word within these utterances. Method: Seven children with CP and eight typically developing children participated in the experiment. Stress on target words in two sentence positions was elicited through a picture-based question-answer paradigm. Acoustic parameters of stress [duration, intensity and fundamental frequency (F0)] were measured and compared between stressed and unstressed target words. For the perception experiment, ten listeners were asked to determine the position of the stressed word in the children's productions. Result: Acoustic measures showed that at group level the typically developing children used all three acoustic parameters to mark sentence stress, whereas the children with CP showed changes in duration only. Individual performance variations were evident in both groups. Perceptually, listeners were significantly better at identifying the stressed words in the utterances produced by the typically developing children than those of the children with CP. Conclusion: The results suggest that children with CP can manipulate temporal speech properties to mark stress. This ability to modulate acoustic-prosodic features could be harnessed in intervention to enhance children's functional communication.