My previous research (co-authored with Prof. Virginia M. Gathercole) concentrated on how immersion in native English-speaking environment influenced Akan-English bilinguals' production of English interdental fricatives. We found an overall better performance on voiceless /θ/ than voiced /ð/, but also effects of phonological environment, age of acquisition, and length of residence, supporting the view that "in determining speakers' proficiency in the second language, we must consider all of these factors—phonological environment, age of acquisition, and length of stay—together to gain a comprehensive picture of development".
Active Research Projects
Acquisition of (Complex) Speech Sound Systems
Currently, I am working on Ga-speaking children's acquisition of complex stops (/kp/ & /gb/). I am trying to understand when children show adult-like productions of these stops. And when children produce errors or simplify their complex stops, what is really driving these simplifications? Do complex stop simplifications show any evidence of covert contrast and/or neutralization? Are simplifications context-specific? How accurate is children's perception of these stops in adult speech? These are intriguing questions that my current project seeks to answer. Addressing these questions gives us an idea about the developmental stages that children go through, and the phonetic cues they use comparable to adults as they gain mastery of their phonological systems. Providing answers to these questions also increases our understanding of crosslinguistic variation of complex stop production. More practically, these questions have implications for the emerging speech language pathology field in my native country, Ghana. This research also has broader implications about the nature of bilingualism in general.
Vocalic Variation & Acquisition
Multilingualism is not uncommon in our world. In Accra, Ghana, the city operates on a system of about four languages (i.e., Akan, Hausa, Ga, English). This diverse multilingualism in Accra has consequences for language contact and language learning since speakers of the different languages interact and the languages influence one another. Thus, as speakers of language/dialect A (LA) speak and interact with speakers of languages/dialects B (LB), features of LA can find their way into LB, and vice versa. When learning a language, children hear both the contact and non-contact influenced forms of language from adults speaking to them, and children will have to compute and keep track of all of these different forms before they settle on a specific one for their day-to-day usage. For example, children acquiring Akan in Accra hear [asu], [æsu], and [esu], all of which mean to ‘has cried’ and derived from the underlying representation /asu/– these are the forms children have to keep track of and make decisions about as they learn the language. The differences in forms that children hear occur at all levels of linguistic analysis (i.e., phonological, morphological, and syntactic levels) and children acquiring these languages have to process, store, and manage the variation they encounter as part of linguistic maturation in a multilingual community. Given how variable adult speech is, how do children settle on one form from among the different forms of identical-meaning linguistic units they are exposed to? Do they even recognize or know that there exist different forms for the same linguistic units? Do children of different ages behave differently with regards to variability in language input they encounter from adult speakers? Does variation in adult speech reveal anything about sound change? What are the linguistic and social factors that constrain these variations?