The continuity of babble and speech in children with specific expressive language delay

A natural language sample of babble and words was obtained for 37 two-year-olds with severe specific expressive language delay. Variables derived from this sample were used to predict individual differences in expressive language scores 5 months later. The rate of word use was positively related to language outcome, whereas rate of vowel babble was negatively related to outcome. Together, these two variables accounted for 41% of the variance in language outcome test scores. The addition of one nonlinguistic variable, a measure of behavior problems, allowed the prediction equation to account for over 50% of the variance in expressive language outcome. The single strongest correlate of language outcome was the proportion of consonantal to vowel babble. The degree of social responsiveness of babble and the length of babble were not related to later language scores. These findings indicate that for children with specific expressive language delay, vowel babble competes with expressive language, consonantal babble facilitates expressive language, and the length and social responsiveness of babble are independent of expressive language. The continuity between babble and speech is multidimensional and multidirectional.