Factors Affecting Communication Outcomes for Deaf and Multilingual Learners: A Systematic Review

Deaf and hard of hearing (DHH) children who are exposed to more than one spoken language can be described as deaf and multilingual learners (DMLs). Increased globalisation and technological advancements in hearing amplification mean an increasing number of children who are DHH access more than one spoken language (with and without the presence of signed languages). A growing body of evidence suggests that DMLs can develop competency in more than one spoken language. However, critical evaluation of factors contributing to positive outcomes appears limited.

The purpose of this systematic review was to identify factors that facilitate and inhibit the development of listening, speech, and language skills in more than one spoken language for DMLs.

Following PRISMA guidelines, searches of seven databases were conducted. The methodological quality of the studies used the Quality Assessment with Diverse Studies (QuADS) tool. Seventeen studies met the inclusion criteria. All studies measured outcomes in a home language and the majority community language. Forty-two different outcome measurement/assessment tools were used, making comparison across the studies difficult.

A range of factors emerged from the interventions, which supported or inhibited the outcomes for DMLs. The results of this review provide insights for practitioners working with DMLs into the factors that promote spoken multilingual language learning and factors that limit positive listening, speech, and language outcomes. The results also contribute to recommendations for researchers to enable the multilingual outcome measurement for DML studies.

The listening, speech, and language outcomes of DMLs are enhanced through interventions in each of the spoken languages to which the child is exposed. This is facilitated by increased engagement of parents who are encouraged to maintain their home language. Furthermore, culturally inclusive practices promote multilingual language development in DMLs and should be included in informing policy decision-making.

What is already known on the subject The term deaf and multilingual learners (DMLs) encompasses deaf learners who are exposed to and learning more than one spoken and/or signed language. The focus of this paper is on deaf and hard of hearing (DHH) children in environments where more than one spoken language is used. There is a growing body of literature focusing on the listening, speech, and language outcomes of DMLs. Much of the literature focuses on communication outcomes in one language (namely the majority community language). There are few studies that measure outcomes in more than one spoken language for DMLs. What this study adds to existing knowledge This paper reviews studies that have measured the listening, speech and language outcomes of DMLs in more than one spoken language. Typically, the majority community language and a different home language (spoken). The results reveal that interventions provided in each language heard and spoken by the DML and their family acts as a facilitator for improved outcomes in each language. Interventions provided in one language only are a barrier to positive multilingual language outcomes. Language exposure in the home language was also a facilitator for positive home language outcomes. Reduced parental engagement and interventions in only one language inhibited multilingual outcomes for DMLs. What are the practical and clinical implications of this work? The paper provides guidance for practitioners when supporting the communication development of DMLs. The provision of listening, speech, and language interventions in each of the languages spoken by the DML and their family facilitates language outcomes. Interventions that are culturally and linguistically adapted and enhance parental engagement also enhance multilingual outcomes. This paper provides evidence to support strategic planning for hearing services to meet the needs of DMLs.