The Relationships Among Vocal Variability, Vocal-Articulatory Coordination, and Dysphonia in Children.

Abstract

OBJECTIVE\nThe purpose of this study was to evaluate the relationship between vocal variability and variability of vocal-articulatory coordination in children. Furthermore, this study examined if this relationship was impacted by pediatric dysphonia.\n\n\nSTUDY DESIGN\nRetrospective analysis of speech samples in the Arizona Child Acoustic Database.\n\n\nMETHODS\nSpeech samples from children 2-7 years of age were selected for analysis. Vocal variability was defined as the coefficient of variation (CoV) of fundamental frequency, taken from the center of sustained vowels. Variability of vocal-articulatory coordination was defined as the CoV of voice onset time (VOT) of voiceless stop consonants. Both objective and subjective measures of dysphonia were completed for each participant.\n\n\nRESULTS\nChildren had a negative correlation between VOT variability and vocal variability. Further analysis indicated that this relationship was present in children with typical developmental levels of dysphonia but absent for children with moderate to severe dysphonia. Increased dysphonia severity was associated with increased vocal variability.\n\n\nCONCLUSION\nIncreased VOT variability was associated with decreased vocal variability in children with dysphonia severities consistent with typical vocal development. However, this relationship was not present in children with moderate to severe dysphonia. This study suggests that future work is needed to examine the relationships between the vocal system and vocal-articulatory coordination in children with and without diagnosed voice disorders.