Examining Vocal Tract Coordination in Childhood Apraxia of Speech with Acoustic-to-Articulatory Speech Inversion Feature Sets

Childhood apraxia of speech is a genetically driven, neurodevelopmental speech sound disorder with speech deficits theorized to reflect difficulty in the spatiotemporal programming of speech movements. Therefore, this work examined how well articulatory coordination features generated from audio-estimated kinematic data distinguished speakers with childhood apraxia of speech versus non-apraxic speech sound disorder. Two correlation-based feature sets motivated by recent literature demonstrated high performance in replicated 6-fold nested cross validated studies, with no statistically significant difference between feature sets (mean AUROC = .90, σ = .04). An ablation study emphasized the importance of source-filter coordination in this population of apraxic speakers, with the source-ablated feature set performing significantly worse than the lip-ablated, the tongue-ablated, and full feature set (ΔAUROC = -.19, SE = 0.01, p < .001).