A follow-up study of phonological development in bilingual children: Implications for clinical assessment

A lack of information about typical phonological development in bilingual children presents as a challenge to many speech-language pathologists assessing bilingual children with suspected speech sound disorder. The purpose of the current study was to investigate age-related changes in speech accuracy (percentage of consonants correct) and error production in Korean-English bilingual children, drawn from a larger study conducted in New Zealand. Sixteen Korean-English bilingual children were followed up at a six-month interval, totalling three time points of data collection. They were aged between 3;1 and 5;11 at the first point of data collection. The Diagnostic Evaluation of Articulation and Phonology was used to obtain single-word samples in English and the Assessment of Phonology and Articulation for Children was used for Korean. We found considerable individual variations in the longitudinal data. Age-related changes in speech accuracy were not sensitive to those changes in error production. Significantly, we found some error patterns emerged during the course of development, instead of being progressively resolved with age. Unlike previous findings in the literature with monolingual children, the findings related to re-emergence of error patterns were not limited to young children. Our findings suggest that speech-language pathologists should take a considered approach to identifying bilingual children with speech sound disorder solely based on the information provided in cross-sectional studies. We suggest that a follow-up session may provide valuable information facilitating the clinical assessment procedure to identify bilingual children with speech sound disorder.