A systematic review and meta-analysis of the development of coarticulation in child speech

Coarticulation, the temporal and spatial overlap of speech gestures, is known to develop throughout childhood. However, methodological differences across studies have made it challenging to characterize its developmental trajectory. This meta-analysis synthesizes findings from 21 studies examining coarticulation in children aged 3–10 years (initial search yielded = 325 results; 199 papers underwent title-abstract screening). We normalized articulatory and acoustic measures of coarticulation from the selected works and grouped participants into 2-year age bins. Effect sizes (Hedges' g) will be calculated for each age bin and analyzed using mixed-effects meta-regression to assess relationships between the degree of coarticulation and age. Our findings will indicate whether coarticulatory patterns systematically change throughout childhood, and at what developmental time point this change occurs. This analysis will provide the first quantitative synthesis of developmental coarticulation research to determine how mature coarticulatory patterns emerge as children develop and refine their speech motor control. Results will have implications for models of speech motor development and clinical assessment of speech production in children.