Moving Beyond Single Word Acquisition of Speech Sounds to Connected Speech Development With Dynamic Assessment

Purpose: The aim of this study was to document speech sound development across early childhood from a dynamic assessment (DA) perspective that captures a breadth of linguistic environments using the Glaspey Dynamic Assessment of Phonology (Glaspey, 2019), as well as to provide normative data for speech-language pathologists to compare speech skills when making clinical decisions and provide historical context. Targets of English were evaluated via DA for the (a) age of acquisition in single words; (b) continued development through connected speech; (c) early, mid, and late sequence; and (d) differences between single word and connected speech productions. Method: Data were extracted from the reported results of the norming study for the Glaspey Dynamic Assessment of Phonology, which included a representative sample of 880 children ages 3 years to 10;11 (years;months). Comparisons were made with 49 items including multisyllabic words, clusters, and phonemes of English across word positions. Results: Assessment with DA showed that acquisition in single words is nearly complete by age 6 years with a 90% mastery level, and the sequence suggests an Early-13, Mid-16, and Late-14 for items by word position. In connected speech, a wider range of progression is evident from the emergence of sound production at 50%, 75%, and 90% mastery levels with observed changes between ages 3 and 10 years. Conclusions: Given a DA approach across connected linguistic environments, children continue to progress in their development of speech sounds from early childhood well into their school-age years and for some sounds beyond the age of 10 years. DA challenges the language system to better reflect children’s developmental progression.