Acoustic-Phonetic Characteristics in Children with Cerebral Palsy and Deaf Children Using PRAAT Software: A Comparative Exploratory Study

Abstract

This comparative acoustic study investigates the physical and phonetic characteristics of speech production in children diagnosed with cerebral palsy (CP) and profoundly deaf children compared against typically developing peers. Employing an exploratory descriptive-comparative multi-case design, acoustic data were elicited from a stratified cohort of six pediatric subjects ($N=6$) aged 7 to 8 years across three matched dyads: neurotypical controls, children with cerebral palsy presenting with dysarthric speech, and deaf children enrolled in specialized pedagogical rehabilitation. Sustained vocalizations of three cardinal vowels—[a], [o], and [i]—were recorded under standardized acoustic conditions and processed using PRAAT software. Evaluated parameters comprised fundamental frequency ($F_0$ / pitch), mean intensity, perturbation metrics (local jitter% and local shimmer%), vocal tract resonance formants ($F_1$, $F_2$, and $F_3$), and harmonics-to-noise ratio (HNR).

The empirical findings demonstrate pronounced acoustic divergences across clinical groups: children with cerebral palsy displayed aerodynamic instability, elevated shimmer, and restricted formant dispersion attributable to neuromotor spasticity and impaired speech-breathing coordination. Conversely, deaf children exhibited vocal destabilization characterized by marked pitch drift, elevated jitter and shimmer, and depressed HNR, reflecting the disruption of auditory feedback. Pronounced intra-group heterogeneity was documented, demonstrating that compensatory phonatory adaptations remain individualized. These outcomes validate the operational hypotheses, underscoring the necessity of integrating computerized acoustic assessment into speech-language therapy for diagnostic profiling and targeted rehabilitation.