Typical and atypical multilingual speech acquisition

Historically, the focus of studies of speech acquisition in bilingual children was to compare their skills to monolingual children (e.g. Watson, 1991). The finding from these studies was that speech acquisition was slower in both typically developing multilingual children and those with speech sound disorders (SSD)1 compared with monolingual children. However, recently, the finding of slower speech acquisition in multilingual children has been shown to be both accurate and inaccurate. That is, in comparison to monolingual children, multilingual children exhibit speech sound skills that are less advanced (i.e. negative transfer) and more advanced (i.e. positive transfer) than their monolingual peers. Moreover, results from those studies have indicated that speech sound skills are not simply mirror images of each other in the two languages, but are distributed somewhat differently in each constituent language, owing to the phonotactic properties of the languages being acquired. The purpose of this chapter is to examine positive transfer, negative transfer and cross-linguistic effects during the course of speech sound development and disorders in multilingual children.