Data-Driven Subclassification of Speech Sound Disorders in Preschool Children

Abstract

Purpose The purpose of the study was to determine whether distinct subgroups of preschool children with speech sound disorders (SSD) could be identified using a subgroup discovery algorithm (SUBgroup discovery via Alternate Random Processes, or SUBARP). Of specific interest was finding evidence of a subgroup of SSD exhibiting performance consistent with atypical speech motor control. Method Ninety-seven preschool children with SSD completed speech and nonspeech tasks. Fifty-three kinematic, acoustic, and behavioral measures from these tasks were input to SUBARP. Results Two distinct subgroups were identified from the larger sample. The 1st subgroup (76%; population prevalence estimate = 67.8%–84.8%) did not have characteristics that would suggest atypical speech motor control. The 2nd subgroup (10.3%; population prevalence estimate = 4.3%– 16.5%) exhibited significantly higher variability in measures of articulatory kinematics and poor ability to imitate iambic lexical stress, suggesting atypical speech motor control. Both subgroups were consistent with classes of SSD in the Speech Disorders Classification System (SDCS; Shriberg et al., 2010a). Conclusion Characteristics of children in the larger subgroup were consistent with the proportionally large SDCS class termed speech delay; characteristics of children in the smaller subgroup were consistent with the SDCS subtype termed motor speech disorder—not otherwise specified. The authors identified candidate measures to identify children in each of these groups.

Investigating intervention dose frequency for children with speech sound disorders and motor speech involvement

“…, Shriberg ; Vick et al . ). The SDCS broadly categorizes children into two groups: those with speech delay (SD) and those with motor speech disorder (MSD).…”

“…It forms the largest group of preschool age children who have been diagnosed with SSD with prevalence estimates between 67.8% and 84.8% (Vick et al . ). Children with SD benefit from speech therapy approaches that strengthen acoustic–phonetic representations for speech (Rvachew and Brosseau‐Lapré ).…”

Polysyllable productions in preschool children with speech sound disorders: Error categories and the Framework of Polysyllable Maturity

“…The sample of younger children demonstrated stress inaccuracy of 29.5% on a sample of five repetitions of six disyllabic words. The stress inaccuracy reported by Vick et al (2014) represents markedly less stress inaccuracy than the 45.2% demonstrated by this sample although this discrepancy is likely due to the increased stress complexity of polysyllables over disyllables, and the larger speech sampling task used in the current study. Interestingly, children with typically developing speech and language who demonstrate more phonotactic accuracy (as measured by fewer consonant and vowel deletions) may temporarily achieve reduced stress accuracy as their polysyllable productions mature (James, 2006;James et al, 2008).…”

“…Recent evidence suggests that children with SSD may be classified in to subgroups based on speech production accuracy across a number of disyllabic word and polysyllable tasks (Vick et al, 2014). Thus, research is needed to compare the information yielded from a routine speech sampling task containing relatively few polysyllables with a polysyllable-specific sampling task in preschool children with phonologically-based SSD of unknown origin.…”

“…Evidence to support this idea comes from research on typical speech acquisition. When compared to monosyllables, polysyllables take a longer time to acquire (James et al, 2008) and, when sampled, may assist with the identification of children with different sub-classifications of SSD (Vick et al, 2014). What follows is an overview of literature on typically developing children' acquisition of polysyllables, and consideration of how polysyllables might be sampled, analysed and measured.…”