Validity of Parent Ratings of Speech Intelligibility for Children with Cerebral Palsy

Aim: To examine the relationship between subjective parent ratings of intelligibility and objectively measured intelligibility scores for children with cerebral palsy (CP) with differing levels of speech severity. Method: Fifty children (84-96 months) with CP were classified into groups based on intelligibility scores during a speech elicitation task - high intelligibility (90% or higher), mild-moderate intelligibility reduction (61-89%), and severe intelligibility reduction (60% or lower). Parent ratings of understandability (on a 7-point scale) were compared to intelligibility scores gathered from 100 naïve listeners. Results: For children with mild-moderate and severe intelligibility reduction, there was a large range of variability in parent ratings. For children with high intelligibility, ratings were consistent with intelligibility scores. There was a range of intelligibility scores within each rating, especially in the middle of the scale. Conclusions: For children with mild-moderate intelligibility deficits, parent ratings may best be used in conjunction with objective measurement of intelligibility.