Title: The Speech Disorders Classification System (SDCS)
Citation: Shriberg, L. D., Kwiatkowski, J., & Mabie, H. L. (2019). Estimates of the prevalence of motor speech disorders in children with idiopathic speech delay. Clinical Linguistics & Phonetics. doi:10.1080/02699206.2019.1595731. [Epub ahead of print].
Abstract: The goals of this research were to obtain initial estimates of the prevalence of each of four types of motor speech disorders in children with idiopathic Speech Delay (SD) and to use findings to estimate the population-based prevalence of each disorder. Analyses were completed on audio-recorded conversational speech samples from 415 children recruited for research in idiopathic SD in six USA cities during the past three decades. The speech and motor speech status of each participant was cross-classified using standardized measures in the finalized version of the Speech Disorders Classification System. A total of 82.2% of the 415 participants with SD met criteria for No Motor Speech Disorder at assessment, 12% met criteria for Speech Motor Delay, 3.4% met criteria for Childhood Dysarthria, 2.4% met criteria for Childhood Apraxia of Speech, and 0% met criteria for concurrent Childhood Dysarthria and Childhood Apraxia of Speech. Population-based prevalence estimates for the four motor speech disorders were calculated from epidemiological studies of SD conducted in Australia, England, and the USA. The estimated population-based prevalence in three of four motor speech disorders at 4 to 8 years of age were Speech Motor Delay: 4 children per 1,000; Childhood Dysarthria: 1 child per 1,000; and Childhood Apraxia of Speech: 1 child per 1,000. Findings are interpreted to indicate a substantial prevalence of motor speech disorders in children with idiopathic SD.
About the Lab: Speech sound disorders (SSD) put children at risk for literacy development, reduced peer acceptance, and limitations in vocational options. The research goals of the Phonology Lab are to understand the causal pathways that lead to subtypes of SSD so that clinicians can select the appropriate intervention approach for each child, and researchers can conduct studies leading to the prevention of some subtypes of SSD. We are studying genomic, motoric, and speech processing correlates of idiopathic SSD and SSD in the context of complex neurodevelopmental disorders (e.g., autism, Down syndrome, fragile X syndrome, galactosemia, FOXP2 disruptions, 22q11.2 deletion, and 16p11.2 deletions and duplications).