Acoustic markers of sentence stress in children with dysarthria and cerebral palsy

Developmental dysarthria in children with cerebral palsy (CP) is often associated with respiratory and phonatory difficulties as well as vocal tract dysfunction, which can affect prosodic control. However, only few studies have investigated the use of prosody in children with dysarthria and CP in greater detail, with little information on the use of acoustic cues to mark linguistic functions. This study aims to increase our current understanding of prosodic abilities in children with dysarthria and CP by investigating children’s ability to stress words in short utterances. Eight children with dysarthria due to CP and eight matched typically-developing children completed a picture description task eliciting stress in different utterance positions. Data were analysed acoustically obtaining measures on duration, intensity and fundamental frequency (F0). Results show that the typically-developing children used all three acoustic parameters to mark stress, whereas the children with dysarthria only employed duration to differentiate between stressed and unstressed words. The findings suggest that the current group of children with CP had some control of the temporal aspects of speech, but were unable to manipulate F0 and intensity to the same effect.