Age Norms for Auditory-Perceptual Neurophonetic Parameters: A Prerequisite for the Assessment of Childhood Dysarthria.

Purpose The aim of this study was to collect auditory-perceptual data on established symptom categories of dysarthria from typically developing children between 3 and 9 years of age, for the purpose of creating age norms for dysarthria assessment. Method One hundred forty-four typically developing children (3;0-9;11 [years;months], 72 girls and 72 boys) participated. We used a computer-based game specifically designed for this study to elicit sentence repetitions and spontaneous speech samples. Speech recordings were analyzed using the auditory-perceptual criteria of the Bogenhausen Dysarthria Scales, a standardized German assessment tool for dysarthria in adults. The Bogenhausen Dysarthria Scales (scales and features) cover clinically relevant dimensions of speech and allow for an evaluation of well-established symptom categories of dysarthria. Results The typically developing children exhibited a number of speech characteristics overlapping with established symptom categories of dysarthria (e.g., breathy voice, frequent inspirations, reduced articulatory precision, decreased articulation rate). Substantial progress was observed between 3 and 9 years of age, but with different developmental trajectories across different dimensions. In several areas (e.g., respiration, voice quality), 9-year-olds still presented with salient developmental speech characteristics, while in other dimensions (e.g., prosodic modulation), features typically associated with dysarthria occurred only exceptionally, even in the 3-year-olds. Conclusions The acquisition of speech motor functions is a prolonged process not yet completed with 9 years. Various developmental influences (e.g., anatomic-physiological changes) shape children's speech specifically. Our findings are a first step toward establishing auditory-perceptual norms for dysarthria in children of kindergarten and elementary school age. Supplemental Material https://doi.org/10.23641/asha.12133380.