Reading and Spelling Abilities of Deaf Adolescents With Cochlear Implants and Hearing Aids
Margaret Harris* and Emmanouela Terlektsi
+ Author Affiliations
Oxford Brookes University
*Correspondence should be sent to Margaret Harris, Department of Psychology, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK (e-mail:
margaretharris@brookes.ac.uk).
Received March 16, 2010.
Revision received June 3, 2010.
Accepted June 6, 2010.
Abstract
A total of 86 deaf children aged between 12 and 16 years were recruited from schools for the deaf, specialist units attached to a school, and mainstream schools. Approximately one-third used hearing aids, one-third had received a cochlear implant before 42 months, and one-third had been implanted later. The 3 subgroups were matched for age and nonverbal IQ, and all had an unaided hearing loss of at least 85 dB. Assessments revealed mean reading ages that were several years below chronological age for all 3 groups. However, participants in the hearing aid group performed best. Reading levels were not predicted by age of diagnosis or degree of hearing loss, but there was a relationship between reading level and presence of phonetic errors in spelling. There were also differences in educational setting, with the great majority of children in the hearing aid group in a school for the deaf and relatively more of the children with cochlear implants being educated in a unit or mainstream setting.
Attaining functional literacy is a key to success in a literate society, yet many children and young people, especially those who are born deaf or become so in the first months of life, find this a difficult if not impossible achievement. Numerous studies, conducted over the last 30 years, have shown that the great majority of deaf children find literacy a challenge, achieving significantly less than hearing peers in both reading (Allen, 1986; Conrad, 1979; DiFrancesca, 1972; Lane & Baker, 1974; Lewis, 1996; Moog & Geers, 1985; Trybus & Karchmer, 1977) and writing (Mayer, 1998, 2007).
The gap between deaf children and hearing peers tends to widen with age (Marschark & Harris, 1996) and so difficulties become more apparent as children progress through school. A recent study (Kyle & Harris, 2010) found a mean delay of 1 year in the reading scores of a group of 8-year-old deaf children: This had increased to a 3-year delay at age 11 years. A comparable cohort of 14-year-old deaf children (Harris & Moreno, 2004) showed an average reading delay of over 4 years. These average delays hide a very considerable degree of individual variation. For example in, the Kyle and Harris cohort, some children made no reading progress at all in 1 year whereas others achieved a whole year of reading progress over the same period.
In order to understand why literacy is so challenging for many deaf children, it is pertinent to consider the skills that underpin learning to read an alphabetic script, such as English, for hearing children. Two key components—knowledge of spoken English and phonological awareness—have been found to underpin the development of literacy. Oral language and vocabulary predict reading development (Bowey & Patel, 1988; Dickinson, McCabe, Anastasopoulos, Peisner-Feinberg, & Poe, 2003); and the ability to identify and manipulate phonemes within words—core aspects of phonological awareness—have been shown to be key to early reading success for hearing children (Muter, Hulme, Snowling, & Stevenson, 2004).
The emerging picture of predictors of deaf children's literacy suggests that broadly similar skills are important although there are some notable differences. As with hearing children, the most compelling data come from longitudinal studies that have examined factors predicting reading outcomes over a period of 1 or more years. One such study (Harris & Beech, 1998) found that, between the ages of 5 and 7 years, speech intelligibility, phonological awareness, and language comprehension predicted reading development. In a study of 6-year-old French children, early phonological awareness skills, including rhyme judgment and rhyme generation, predicted the reading progress made over 1 year (Colin, Magnan, Ecalle, & Leybaert, 2007). A recent study (Kyle & Harris, 2010) examined reading progress over a 3-year period, from the age of 7 years. Although most children showed reading delays at the end of the study, those with better vocabulary and speechreading skills at age 7 years exhibited less severe delays. This latter finding was consistent with the results of a comparison between matched groups of good and poor deaf readers at age 8 (Harris & Moreno, 2006), which showed a significant difference in speechreading ability in favor of the better readers. All these studies, with the exception of Colin et al. (2007), assessed deaf children from a variety of educational settings so these findings are not specific to preferred mode of communication. Indeed, knowledge of spoken English and speechreading skills appear to be as important for children who sign and for those whose education is predominantly oral.
The longitudinal relationship between phonological awareness and speechreading appears to be a complex one. In Kyle and Harris (2006), phonological awareness was not correlated with reading ability at age 7 when the children were first assessed. However, at that age phonological awareness was strongly associated with speechreading. Early speechreading also predicted phonological awareness 1 year later. By the end of the study, 3 years later, phonological awareness was significantly correlated with reading ability (Kyle & Harris, 2010) but it was reading ability that predicted later phonological awareness rather than the other way round. These patterns of results suggest that deaf children's phonological abilities may develop as a consequence of learning to read rather than being a prerequisite of reading, as in hearing children, and that, in the early stages, development is mediated by speechreading.
The complementary roles of speechreading—as a mediator of phonological awareness—and knowledge of English, especially English vocabulary, are illustrated by the finding from Kyle and Harris (2006) that speechreading was the strongest predictor of single word reading ability, whereas vocabulary knowledge was the strongest predictor of written sentence comprehension. This echoes the principle of the simple view of reading (Hoover & Gough, 1990) that two components, decoding and linguistic comprehension, underpin the development of skilled reading. It would appear that this is equally true for deaf and hearing children.
Although speechreading appears to provide a route to the development of phonological awareness among deaf children, it might be expected that increased access to sound would promote knowledge of the oral language and provide a direct route to phonological awareness. This would, in turn, be expected to have an impact on literacy. The technological developments in hearing aids that have taken place over the last two decades have held out the prospect of increased access to speech for deaf children. Chief among the innovations that have taken place is the provision of cochlear implants. In the United Kingdom, these are provided by the National Health Service and so have become increasingly available for children, irrespective of parental means (Archbold, Harris, et al., 2008).
There is now a substantial body of evidence showing that cochlear implantation improves speech perception and production and facilitates the development of spoken language (Archbold et al., 2000; Cleary, Pisoni, & Geers, 2001; Geers, 2002; O'Donoghue, Nikplopoulos, & Archbold, 2000; Pisoni & Geers, 1998; Tait, Nokolopoulos, Archbold, & O'Donoghue, 2001; Thoutenhoofd, et al., 2005; Watson, Archbold, & Nikolopolous, 2006; Watson, Hardie, Archbold, & Wheeler, 2008). In contrast to the findings about spoken language development, evidence concerning the impact on reading and writing has been inconsistent (Archbold, Harris, et al., 2008; Marschark, Rhoten, & Fabich, 2007).
There are a number of issues to consider in evaluating literacy outcomes. Many children who receive a cochlear implant have complex needs that place limitations on their capacity to become literate (Edwards, 2007). In addition, there are other deaf children who do not have any recognized additional needs but who have a level of nonverbal intelligence that is significantly below normal. Arguably, children with an IQ score that is more than 1 standard deviation (SD) below the mean would not be expected to show age-appropriate levels of reading. However, many studies do not assess nonverbal IQ in evaluating literacy outcome following implantation so it is not possible to fully evaluate their findings.
Another important factor is age at implantation (Archbold, Harris, et al., 2008). This has been falling steadily since the first pediatric implants were carried out and, in the United Kingdom, many children are now implanted around the age of 2 years or even younger. This was not the case a few years ago, and depending on the point at which data were collected, age at implantation may have been considerably higher than current norms. For example, a small-scale study (Boothroyd & Boothroyd-Turner, 2002) found continued delays in reading ability 4 years after implantation but the average age at implantation was 5.8 years. Another small-scale study (Spencer, 2004) investigated the language performance of children who had been implanted before 36 months. She reports reading comprehension scores within 1 SD of hearing peers and a strong correlation between spoken language and reading. In a study of 181 children, all of whom had received an implant before the age of 5 years (Geers, 2003), over half were reading at an age-appropriate level. Notably, there was considerable variability within the group although a number of factors predicted reading competence, namely, mainstream educational placement, wide dynamic range using recent technology, longer memory span, and use of phonological coding. As in the Spencer (2004) study, reading ability was predicted by linguistic competence (Tobey, Geers, Brenner, Altuna, & Gabbert, 2003). However Geers (2003) did not find an association between reading level and age at implantation as many other studies have done (Archbold, Harris, et al., 2008).
Two recent European studies compared literacy attainment in deaf children with cochlear implants and peers with hearing aids. Among a sample of 152 deaf pupils in Scotland, those with cochlear implants scored comparatively higher on reading and writing than peers with hearing aids (Thoutenhoofd, 2006); and a similar pattern emerged from a study of 550 deaf pupils in the Netherlands (Vermeulen, van Bon, Schreuder, Knoors, & Snik, 2007). Notably, however, both studies found children with implants to be delayed when compared with hearing children. In the former study, the mean age at implantation was 37 months for primary school pupils and 91 months for secondary school pupils. In the latter study, the mean age at implantation was 74 months and the mean age at which reading was assessed was 153 months.
Perhaps the most optimistic view of the benefits of cochlear implantation comes from a study of children in the United Kingdom who were implanted by the Nottingham Cochlear Implant Team (Archbold, Harris, et al., 2008). This study followed up 105 children and assessed their reading levels at 5 and 7 years post-implantation. There was a wide variation in age at implant and so the sample was divided into those implanted relatively early (at or before the age of 42 months) and those implanted later, that is between 43 and 84 months. There was a strong and positive association between outcomes and age at implantation, and among the subgroup of children whose nonverbal IQ was 85 or above, those who had been implanted at or under the age of 42 months were reading at an age-appropriate level at both assessment points.
Seven years post-implantation most of the children in the Archbold, Harris, et al. (2008) study were approaching the end of primary schooling where the demands of literacy begin to increase as readers are required to deal with more complex sentences, abstract concepts, and the integration of ideas across extended text. There are analogous demands on writing skills. These demands continue to increase as children move into secondary school and, in their final years of schooling, adult levels of literacy are required. The question remains as to how well children and young people with a cochlear implant fare as they cope with these demands. Evidence from a follow-up study (Geers, Tobey, Moog, & Brenner, 2008) suggests that early levels of attainment tend not to be sustained. Geers et al. (2008) were able to follow up 26 of the children assessed in an earlier study (Geers, 2003) and found that, although they were reading at an age-appropriate level when they were 8–9 years old, they had an average reading delay of 2 years by the time they were 15–16 years old (for a discussion of this finding, see Marschark et al., 2007). This suggests that early reading success following a cochlear implant may not be sustained in the final years at school.
The Archbold, Harris, et al. (2008) study focused exclusively on children with a cochlear implant and it did not compare outcomes with those of deaf peers using a conventional hearing aid. There have been considerable technological advances in hearing aids (Ackley & Decker, 2006) and many children in the United Kingdom are now using digital aids that would be expected to give them better access to speech. It is therefore legitimate to ask whether children with a cochlear implant have higher literacy levels than peers who rely on hearing aids.
The aim of this article was to examine the literacy attainment of deaf children aged between 12 and 16 years. The study compared three groups of children who were similar in age, nonverbal IQ, and levels of hearing loss but who differed in the type of aid that they were using. One group used hearing aids, and two had received a cochlear implant either before 42 months or later. The study assessed reading of both single words and text, using standardized tests, and also gathered data on spelling. The spelling data were designed to reveal spelling strategies. Previous studies (Harris & Moreno, 2004, 2006; Mayer, 1998; Sutcliffe, Dowker, & Campbell, 1999) have shown that, in comparison to hearing children of similar reading age, deaf children tend to make very few phonetic spelling errors that correctly capture the sound of a spoken word. Such errors (e.g., spelling scissors as sissers) are very common in the misspellings of hearing children and are taken as evidence that they are using a phonological strategy. The study sought to find out whether there was evidence that children with a cochlear implant were making greater use of a phonological strategy than peers with hearing aids. Finally the study examined the relationship between use of phonological coding and reading level to see whether good readers made greater use of a phonological strategy than poor readers.
there are several others but right now, I gotta visit my dad.
there are some basic older English words that stump anyone. Think of trying to spell tongue phonetically. When it slips your mind, it can drive one crazy!