Effects of speech cues in French-speaking children with dysarthria

Background: Articulatory excursion and vocal intensity are reduced in many children with dysarthria due to cerebral palsy (CP), contributing to the children’s intelligibility deficits and negatively affecting their social participation. However, the effects of speech-treatment strategies for improving intelligibility in this population are understudied, especially for children who speak languages other than English. In a cueing study on English-speaking children with dysarthria, acoustic variables and intelligibility improved when the children were provided with cues aimed to increase articulatory excursion and vocal intensity. While French is among the top 20 most spoken languages in the world, dysarthria and its management in French-speaking children are virtually unexplored areas of research. Information gleaned from such research is critical for providing an evidence base on which to provide treatment. Aims: To examine acoustic and perceptual changes in the speech of French-speaking children with dysarthria, who are provided with speech cues targeting greater articulatory excursion (French translation of ‘speak with your big mouth’) and vocal intensity (French translation of ‘speak with your strong voice’). This study investigated whether, in response to the cues, the children would make acoustic changes and listeners would perceive the children’s speech as more intelligible.
Methods & Procedures: Eleven children with dysarthria due to CP (six girls, five boys; ages 4;11–17;0 years; eight with spastic CP, three with dyskinetic CP) repeated pre-recorded speech stimuli across three speaking conditions (habitual, ‘big mouth’ and ‘strong voice’). Stimuli were sentences and contrastive words in phrases. Acoustic analyses were conducted. A total of 66 Belgian-French listeners transcribed the children’s utterances orthographically and rated their ease of understanding on a visual analogue scale at sentence and word levels.
Outcomes & Results: Acoustic analyses revealed significantly longer duration in response to the big mouth cue at sentence level and in response to both the big mouth and strong voice cues at word level. Significantly higher vocal sound-pressure levels were found following both cues at sentence and word levels. Both cues elicited significantly higher first-formant vowel frequencies and listeners’ greater ease-of-understanding ratings at word level. Increases in the percentage of words transcribed correctly and in sentence ease-of-understanding ratings, however, did not reach statistical significance. Considerable variability between children was observed.
Conclusions & Implications: Speech cues targeting greater articulatory excursion and vocal intensity yield significant acoustic changes in French-speaking children with dysarthria. However, the changes may only aid listeners’ ease of understanding at word level. The significant findings and great inter-speaker variability are generally consistent with studies on English-speaking children with dysarthria, although changes appear more constrained in these French-speaking children.