Interaction in bilingual phonological acquisition: Evidence from phonetic inventories

Purpose. To examine how interaction contributes to phonological acquisition in bilingual children in order to determine what constitutes typical development of bilingual speech sound inventories. Method. Twenty-four children, ages 3-4, were included: eight bilingual Spanish-English-speaking children, eight monolingual Spanish speakers, and eight monolingual English speakers. Single word samples were obtained to derive phonetic inventories. After Dinnsen, Chin, Elbert and Powell for English and Cataño, Barlow, and Moyna for Spanish, the children's inventories were assigned to one of five levels of complexity. Levels were compared for similarities and differences within bilinguals and between monolinguals and bilinguals. Inventories were examined for evidence of interaction in the form of phonological transfer. Results. Bilinguals had phonetic inventories that were commensurate in complexity with monolinguals. Bilingual children acquire two inventories in the same amount of time that monolinguals acquire one, and with the same level of complexity. Evidence of transfer occurred from English to Spanish and vice versa. Implications. These findings are useful for the differentiation of language difference from disorder and aid in avoiding underdiagnosis of speech sound disorders. Although bilingual children maintain separation of phonological structures, a low level of interaction between their two languages exists.