Bilingual children acquire two languages in the same amount of time that monolingual children learn only one. How do they do that? The Bilingual Phonology Lab at the University of Arizona aims to find out. Little is known about typical speech acquisition in bilingual children, and even less is known about bilingual children with speech disorders. The long-term goals of the Bilingual Phonology Lab are to (1) determine the trajectory of typical speech acquisition in bilingual children, taking into consideration how the two languages of bilingual children interact; (2) determine how disorder presents itself in a child that maintains two speech sound systems, and (3) develop evidence-based assessment and intervention tools to help bilingual children with phonological disorders become effective communicators in both of their languages.
The first major study in the Bilingual Phonology Lab is called, "Initial Consonant Deletion in Bilingual Preschoolers: Speech Difference or Speech Disorder?" Historically, children who frequently omit the first sound in a word during speech have been thought to exhibit a speech disorder. Recently, numerous studies have found that typically-developing Spanish-speaking children, both bilingual and monolingual, exhibit this pattern. Leah Fabiano-Smith was awarded a University of Arizona Faculty Seed Grant to examine the question, "Is initial consonant deletion evidence of disorder in bilingual Spanish-English speaking children?" If typically-developing Spanish speaking children do indeed exhibit this error pattern, speech-language pathologists are in danger of diagnosing typically-developing bilingual children with speech sound disorders. The overarching goal of this study is to prevent misdiagnosis of speech disorders in the Latino population.
The second major study underway in the Bilingual Phonology Lab examines a grammatical rule in Spanish called the stop-spirant alternation. In other words, some forceful, louder sounds in Spanish change into softer sounds if they happen to fall into a certain context in a word. We are examining when Spanish-speaking and bilingual Spanish-English speaking children learn this rule. In addition, recent studies suggest that the errors children make on this rule give us information on the structure of the Spanish language. This study has both theoretical and clinical implications for bilingual speech acquisition. We are currently performing acoustic analyses on recordings of bilingual children's speech to aid in answering our research questions. As in the previous study, the findings from this project will aid in distinguishing speech difference from speech disorder in the bilingual Spanish-English speaking population.
In the coming year, we will be collecting new data to examine bilingual children with suspected speech sound disorders. We aim to develop evidence-based diagnostic criteria to separate typically-developing bilingual children from bilingual children with speech sound disorders.