Volubility, consonant, and syllable characteristics in infants and toddlers later diagnosed with childhood apraxia of speech: A pilot study.

PURPOSE: This pilot study explored the volubility, consonant singleton acquisition, and syllable structure development between infants and toddlers (birth-24 months) with typical speech sound production (TYP) and those later diagnosed with childhood apraxia of speech (CAS). METHOD: A retrospective longitudinal between- and within-subjects research design was utilized (TYP N=2; CAS N=4). Vocalizations from participants were analyzed between birth-24 months from home videotapes, volunteered by the children's parents, according to type (nonresonant vs. resonant), volubility, place and manner of consonant singletons, and syllable shape (V, CV, VC, CVC, VCV, CVCV, VCVC, and "Other"). RESULTS: Volubility between groups was not significant but statistically significant differences were found in the number of: resonant and non-resonant productions; different consonant singletons; different place features; different manner classes; and proportional use of fricative, glottal, and voiceless phones. Infants and toddlers in the CAS group also demonstrated difficulty with CVCs, had limited syllable shapes, and possible regression of vowel syllable structure. CONCLUSIONS: Data corroborate parent reports that infants and toddlers later diagnosed with CAS present differently than do those with typical speech sound skills. Additional study with infants and toddlers later diagnosed with non-CAS speech sound disorder is needed. LEARNING OUTCOMES: Readers will: (1) describe current perspectives on volubility of infants and toddlers later diagnosed with CAS; (2) describe current perspectives of the consonant singleton and syllable shape inventories of infants and toddlers later diagnosed with CAS; and (3) discuss the potential differences between the speech sound development of infants and toddlers later diagnosed with CAS and those with typical speech sound skill.