Risk and protective factors to spoken language acquisition for deaf children in the UK

Good spoken language in the early years predicts later academic outcomes (Law et al., 2017) but deafness disrupts the acquisition of spoken language by limiting access to the speech signal due to reduced access to sound, pitch distortion (Hopkins, 2015) and frequency smearing causing an increased susceptibility to noise (Moore, 1996). Despite some success of early language interventions following early identification of deafness (Yoshinaga-Itano et al., 1998) measures of deaf children's communication and language at age 5-years show that ~50% do not meet expected levels.

Deaf children with better spoken language skills in the early years are more likely to acquire age-appropriate literacy skills and attain in school (Mayer et al., 2021), demonstrating the importance of identifying those deaf children most likely to show early language delays.

The effects of socio-economic status are widely acknowledged as risks to language development for all children (Fernald et al., 2013) with a reported average gap in attainment of up to 34 months for children who are socially disadvantaged and deaf when compared to other deaf children (Hutchinson, 2023). Thus, services for deaf children should consider the multiple influences on deaf children's attainment when allocating support.

However, existing research is limited by a) grouping all deaf children into a single category, regardless of level of deafness and/or b) failing to consider influences beyond deafness (e.g. SES, maternal education) that are likely to impact outcomes. Thus, it is not currently possible to accurately identify which deaf children are most at risk of language delays and are most in need of enhanced support.

To meet the heterogeneous needs of deaf children we need to understand the influence of variables relating both to and beyond deafness, and how their interplay affects language outcomes.

This PhD is a unique cross-disciplinary collaboration between psychology, deaf education and a leading charity for deaf children, the Ewing Foundation. It asks: i) What risk and protective factors are related to deaf children's spoken language skills across development?

ii) How do individual (a) levels of deafness and (b) environmental/familial factors at age 2 relate to children's concurrent and later language skills?

iii) How does the prevalence of these risk/protective factors in individual children relate to the level of support they receive from services for deaf children?

The successful student will conduct a review of the relevant literature on the predictors of spoken language acquisition in children who are deaf to identify likely risk and protective factors, before conducting a detailed longitudinal empirical study with families of children who are deaf to collect measures of children's early language development (preschool years), data on a range of individual/environmental/familial factors and information about levels of support received. Analyses will determine concurrent and longitudinal relations between risk/protective factors, language outcomes and levels of support in place.

This will enable us to determine whether the risk and protective factors identified at T1 predict later language development, and whether levels of support children receive reflect measures of their relative risk for language delay.