ABSTRACT
In their examination of the phonetic systems of bilinguals, researchers have generally used one of three approaches. The first involves the comparison of bilinguals or nonnative speakers to monolinguals and/or native speakers to determine whether their language systems are the same or different and is here termed the monolingual-comparison approach.The second attempts to determine the extent to which bilinguals’ two languages are interdependent (merged) or independent and is here designated as the shared-separate approach.The third deals with the effect of age on the development of a secondor dual-language system among bilinguals and is here called the age-effect approach.Most of this chapter is devoted to a consideration of studies representative of these three approaches, which, taken together, provide descriptive and (some) explanatory adequacy. Then attention will be given to three major theories regarding the formation of phonetic systems, which could, if they were supported by further empirical evidence and somewhat refined, provide predictive adequacy. These are Kuhl';s native language magnet theory, Best';s perceptual assimilation model, and Flege';s speech learning model.
