An investigation of the reading, speech, language and phonological processing skills of children using a cochlear implant

Traditionally, children with a significant prelingual hearing loss have attained reading outcomes no higher than fourth grade (Gallaudet Research Institute, 2002; Holt, Traxler & Allen, 1997). With the advent of multi-channel cochlear implantation, children with a significant hearing loss gained the potential to access spoken language and to engage in phonological processing via audition. In children with normal hearing, better reading outcomes have been associated with better phonological processing ability (e.g., Catts & Kamhi, 2005; Griffiths & Snowling, 2001; Muter, Hulme, Snowling, & Stevenson, 2004; Rvachew & Grawburg, 2006; Stackhouse & Wells, 1997 ; Wagner, Torgesen, Laughon, Simmons, & Rashotte, 1993). While there is some evidence that cochlear implantation is associated with improvements in speech, language and reading outcomes (e.g., Geers, 2003; Geers, Nicholas, & Sedey, 2003b; Spencer, Barker, & Tomblin, 2003; Thoutenhoofd, 2006; Tomblin, Spencer, Flock, Tyler, & Gantz, 1999), less is known about the phonological processing abilities of these children. Furthermore, although the outcome research has generally been positive, there has been great variability in performance both within a cohort of children and across studies. Heterogeneous participant profiles, particularly the varying modes of communication used by participants, have made it difficult to draw meaningful conclusions about factors associated with good reading outcomes for children using a cochlear implant. There is a need to determine the reading, speech, language and phonological processing abilities of a homogenous cohort of children using a cochlear implant. Further there is a need to explore whether factors associated with reading outcomes in children with normal hearing such as phonological processing, are also related to reading outcomes in children using a cochlear implant. This thesis documents the reading outcomes, and skills related to reading outcomes in a relatively homogenous group of children who use a cochlear implant and oral communication. The relationships between the children’s performance on tasks of word reading, reading comprehension, speech perception, speech production, language and phonological processing are explored to provide a big picture view of which skills might be related to good reading outcomes