Development of lingual motor control in children and adolescents

An important insight into speech motor control development can be gained from analysing coarticulation. Despite a growing number of acoustic and articulatory studies of lingual coarticulation in children, there are conflicting opinions on how the extent of coarticulation changes during childhood. There is also increasing evidence that age-related patterns vary depending on speech sounds involved. The present study employed ultrasound tongue imaging to compare anticipatory V-on-C coarticulation in 13-year-old adolescents and 5-yearold children, using the consonants /p/ and /t/, which differ in the amount of lingual coarticulation in adult speech. For /p/, the two groups had a similar amount of coarticulation. For /t/, both groups had a vowel effect on the extent of tongue bunching, while only adolescents had an effect on the location of tongue bunching. Token-to-token variability in absolute tongue position was larger in the 5-year-olds. We discuss the findings in relation to previous studies and existing theories.