What long-distance coarticulation can tell us about coarticulatory development

Abstract

It is widely acknowledged that children’s speech gestures overlap more than adults’ in spoken language. Unlike coarticulation in adult speech, which is largely planned (Whalen, 1990), children’s coarticulation appears to stem from their (1) protracted tongue-jaw coordination and (2) inexperience with language. For example, 4- to 7-year-olds with greater phonological awareness tend to coarticulate less within syllables (Noiray, et al., 2019). Long-distance, inter-morphemic coarticulation is another way to demonstrate that children coarticulate for different reasons than adults: by comparing across multiple segments, and contrasting coarticulation within versus across word morphemes, we can invoke speech planning, not just motor control. Since children’s coarticulation is assumed to reflect inexperience and lack of planning, they should coarticulate less than adults in longer-distance environments. N = 51 5- to 10-year-old children and 10 female adults, all bilingual South Bolivian Quechua-Spanish speakers, completed a Quechua morphological elicitation task. Inter-syllabic coarticulation was quantified using a whole-spectrum measure within bare stems (within-morpheme) and inflected nouns (across-morpheme). Results were compared to speakers’ intra-syllabic coarticulation and showed that while children, unsurprisingly, coarticulate more within syllables, they anticipate segments at a longer distance (inter-syllabic and across morphemes) less than adults, only approximating adult-like patterns around age 9.