Orthographic facilitation of vocabulary learning in children with hearing loss

Oral vocabulary acquisition involves the formation of a link between the phonology and semantics of a newly encountered word. There exists a large body of literature that describes the processes involved in vocabulary acquisition and the factors that influence acquisition in children with typical and atypical development (e.g., Chapman, 2000; de Jong,Seveke, & Veen, 2002; Dillon, 2011; He & Arunacham, 2017; Hollich et al., 2000; Kucker, McMurray, & Samuelson, 2015; Nazzi & Bertoncini, 2003; Waxman & Lidz, 2007; Yu &Ballard, 2007). It is widely acknowledged that vocabulary is crucial for the development of language, communication, reading, and literacy (Biemiller, 2009; Lee, 2011; Ouellette, 2006).Therefore, it follows that if children are not able to acquire vocabulary appropriately, it would impact their overall development and academic success. Vocabulary acquisition is a challenge for children with hearing loss, including those who use appropriate hearing devices such as hearing aids and cochlear implants (Sarchet, Marschark, Borgna, Convertino, Sapere, & Dirmyer, 2014). Surprisingly, there is very little research that directly examines the instruction techniques of factors that can support vocabulary learning in children with hearing loss (Luckner & Cooke, 2010). One factor that is being increasingly researched as a mechanism to support oral vocabulary learning is orthography. There exists evidence for the orthographic facilitation of vocabulary learning in children with typical development (e.g., Ricketts, Bishop, & Nation,2009), and in special populations (Lucas & Norbury, 2014; Mengoni, Nash, & Hulme, 2013; Ricketts, Dockrell, Patel, Charman & Lindsay, 2015). This thesis aimed to review the literature on vocabulary acquisition in children with hearing loss and to examine whether they may benefit from the presence of orthography during oral word learning. This thesis is organised in a 'thesis by publication' format, with two parts, that each represent a journal article. Part One: Vocabulary acquisition, orthographic facilitation, and its implications for children with hearing loss : a literature review. This section reviews literature vocabulary acquisition in children with typical hearing and children with hearing loss, the rationale and existing evidence for orthographic facilitation in different groups of children. Part Two: Orthographic facilitation of vocabulary learning in children with hearing loss. This section presents an empirical study to examine the possible facilitatory role of orthography for acquisition of novel picture-word mappings in school-aged children with hearing loss who use spoken language as their main mode of communication. The outcomes of the study are discussed in light of the available literature and possible directions for future research in this area are suggested.