Phonetic skills and vocabulary size were investigated in 37 toddlers (24 to 31 months) identified with specific expressive language impairment and 20 comparison toddlers matched on age, SES, and nonverbal ability. The use of consonants was highly consistent across two contexts: 20 minutes of structured testing and 5 minutes of free play. The comparison children produced almost triple the number of consonant types and five times as many consonant tokens as the late talkers. However, the most frequently present consonants were similar across groups, indicating delayed rather than deviant phonetic development in the late talkers. The late talkers used a much higher proportion of their consonants in initial position than did the normally developing toddlers. Consonant types and tokens were significantly related to reported vocabulary size on Rescorla's (1989) Language Development Survey. No significant predictive relationship was found between either phonetic repertoire or vocabulary size at intake and age 3 language outcome. However, age 3 MLU and IPSyn scores were significantly predicted by age-normed severity of expressive delay at intake (Reynell Expressive z score), with more delayed children showing poorer outcomes.
© 1998 by Cambridge University Press. Available on publisher's site at http://journals.cambridge.org/abstract_S0142716400010559.
Mirak, Jennifer, and Leslie Rescorla. "Phonetic Skills and Vocabulary Size in Late Talkers: Concurrent and Predictive Relationships." Applied Psycholinguistics 19 (1998): 1-17, doi: 10.1017/S0142716400010559.