Jean S. Moog

Spoken Language Scores of Children Using Cochlear Implants Compared to Hearing Age-Mates at School Entry

This study investigated three questions: Is it realistic to expect age-appropriate spoken language skills in children with cochlear implants (CIs) who received auditory-oral intervention during the preschool years? What characteristics predict successful spoken language development in this population? Are children with CIs more proficient in some areas of language than others? We analyzed language skills of 153 children with CIs as measured by standardized tests. These children (mean age = 5 years and 10 months) attended programs in the United States (N = 39) that used an auditory-oral educational approach. Age-appropriate scores were observed in 50% of the children on measures of receptive vocabulary, 58% on expressive vocabulary, 46% on verbal intelligence, 47% on receptive language, and 39% on expressive language. Regression analysis indicated that, after controlling for the effects of nonverbal intelligence and parent education level, children who received their implants at young ages had higher scores on all language tests than children who were older at implantation. On average, children with CIs performed better on certain language measures than others, indicating that some areas of language may be more difficult for these children to master than others. Implications for educators of deaf children with CIs are discussed.

Long-term outcomes of cochlear implantation in the preschool years: From elementary grades to high school

The objective of this study was to document the development of speech, language, and reading skills between primary and secondary school ages in children who received cochlear implants during preschool years. Subjects were a sample of 85 North American adolescents recruited from a larger sample of 181 participants from a previous investigation. Students were first tested in early elementary school (ages eight to nine years) and were re-evaluated in high school (ages 15–18 years) for this study. The methods used were: performance on a battery of speech perception, language, and reading tests. These were compared at both test ages and significant predictors of outcome level identified through multiple regression analysis. Speech perception scores improved significantly with long-term cochlear implant use. Average language scores improved at a faster than normal rate, but reading scores did not quite keep pace with normal development. Performance in high school was most highly correlated with scores obtained in elementary grades. In addition, better outcomes were associated with lower PTA cochlear implant threshold, younger age at implantation and higher nonverbal IQ. In conclusion, early cochlear implantation had a long-term positive impact on auditory and verbal development, but did not result in age-appropriate reading levels in high school for the majority of students.

Receptive vocabulary development in deaf children with cochlear implants: Achievement in an intensive auditory-oral educational setting

Objectives: Deaf children with cochlear implants are at a disadvantage in learning vocabulary when compared with hearing peers. Past research has reported that children with implants have lower receptive vocabulary scores and less growth over time than hearing children. Research findings are mixed as to the effects of age at implantation on vocabulary skills and development. One goal of the current study is to determine how children with cochlear implants educated in an auditory-oral environment compared with their hearing peers on a receptive vocabulary measure in overall achievement and growth rates. This study will also investigate the effects of age at implant on vocabulary abilities and growth rates. We expect that the children with implants will have smaller vocabularies than their hearing peers but will achieve similar rates of growth as their implant experience increases. We also expect that children who receive their implants at young ages will have better overall vocabulary and higher growth rates than older-at-implant children. Design: Repeated assessments using the Peabody Picture Vocabulary Test were given to 65 deaf children with cochlear implants who used oral communication, who were implanted under the age of 5 yr, and who attended an intensive auditory-oral education program. Multilevel modeling was used to describe overall abilities and rates of receptive vocabulary growth over time. Results: On average, the deaf children with cochlear implants had lower vocabulary scores than their hearing peers. However, the deaf children demonstrated substantial vocabulary growth, making more than 1 yr’s worth of progress in a year. This finding contrasts with those of previous studies of children with implants, which found lower growth rates. A negative quadratic trend indicated that growth decelerated with time. Age at implantation significantly affected linear and quadratic growth. Younger-at-implant children had steeper growth rates but more tapering off with time than children implanted later in life. Conclusions: Growth curves indicate that children who are implanted by the age of 2 yr can achieve receptive vocabulary skills within the average range for hearing children.

Estimating the influence of cochlear implantation on language development in children

Research studies reviewed here have identified a wide variety of factors that may influence a childs auditory, speech and language development following cochlear implantation. Intrinsic characteristics of the implanted child, including gender, family socioeconomic status, age at onset of hearing loss and pre-implant residual hearing may predispose a child to greater or lesser post-implant benefit. Intervention characteristics that may influence outcome include age of the child when deafness is identified and amplification and habilitation is initiated, the communication mode used with the child and the type of classroom/therapy employed. Characteristics of the implant itself include generation of technology used, the age of the child when implant stimulation is initiated, and the amount of time the child has used the implant. These factors interact in unpredictable ways, so that isolated correlations between predictor variables and outcome scores may be difficult to interpret. Results for two independent samples of children tested by different laboratories were compared using multiple regression analysis to take into account relationships among predictor variables. Implant age was a significant predictor, and children in both samples who received a cochlear implant sometime between their first and second birthday achieved oral receptive vocabulary levels within one standard deviation of hearing age-mates. Age at implant accounted for a similar proportion of variance in receptive vocabulary outcome scores in each sample. A unique predictor was then added to each analysis. The addition of pre-implant aided threshold not only increased the total predicted variance, but also increased the effect of implant age as a predictor variable. A different result was observed in the other sample, when the added predictor variable was non-verbal IQ, where the estimated contribution of implant age was reduced. Future studies are advised to control for independent contributions of implant age, non-verbal IQ, and pre-implant aided thresholds when examining expected outcomes.

Practical Implications of Cochlear Implants in Children

CHILDHOOD DEAFNESS CAN have serious and far-reaching effects on development but, with appropriate intervention, these effects can be reduced (see, for example, Boothroyd. 1988; Davis & Silverman, 1978; Ling & Ling, 1978). One component of modern intervention is effective use of the auditory capacity possessed by most deaf children. With modern hearing aids and suitable training, this “residual hearing” can play a significant role, and often the primary role, in the development of receptive and expressive spoken language skills and language competence (see, for example, Bess, Freeman, & Sinclair, 198 1 ; Ling & Milne, 198 1 : Ross & Giolas, 1978). There have always been deaf children, however, who have little or no residual hearing. Even with the most powerful hearing aids they perceive only gross variations of speech amplitude over time, and for many, this perception is mediated not by the sense of hearing, but by the sense of touch (Boothroyd & Cawkwell, 1970; Erber, 1978, 1979; Nober, 1967). These children account for, perhaps, 5 to 10% of the population with hearing losses of sufficient severity to prevent the spontaneous acquisition of spoken language skills. They typically have better-ear, three-frequency, average thresholds in excess of 110 dB. With the advent of cochlear implants it has become possible to provide many such children with useful auditory capacity. The purpose of the present paper is to discuss the practical implications of this development. Five questions will be addressed: 1. What exactly are the auditory capacities of implanted children? 2. How much greater are these capacities than could reasonably have been expected from hearing aids? 3. Based on our experience with less severely deaf children, how much difference should the improvement of auditory capacity, after implanta4.

Epilogue: major findings, conclusions and implications for deaf education.

(Ear & Hearing 2003;24;121S–125S) It has now been well established that cochlear implants are reliable and effective devices for significantly improving access to sound for deaf individuals. This study, titled “Cochlear Implants and Education of the Deaf Child,” addresses the impact of cochlear implants on deaf children. The focus of this supplement is on describing the effects of cochlear implants on prelingually deaf children and determining the factors that have a significant impact on their speech perception, speech production, language and reading skills. Half of the children included in the study were enrolled in oral programs with a focus on listening and spoken language and half were enrolled in total communication programs using sign and speech together. The articles in this supplement summarize the most comprehensive study of deaf children with cochlear implants ever reported and the data have implications for instruction/therapy for deaf children and expectations for their development. It is comprehensive in terms of the size of the sample of deaf students, the breadth of areas investigated and the completeness of the test battery in each area. The purpose of the study was to determine the child, family, implant and educational characteristics that account for differences in achievement for 181 implanted children in five outcome skill areas: speech perception, speech production, spoken language, total language and reading. One goal was to determine the correlation among sample characteristics and outcome skills, which indicates the strength of their relationships. Another goal was to determine the extent each sample characteristic contributed independently to differences in performance outcome. The primary goal of the study was to determine the impact of the educational environment and communication method on each of the outcome skills after accounting for the impact of child, family and implant characteristics on the outcome skills. A major strength of the study was the characteristics of the 181 children studied. The group was homogeneous in terms of age at testing (all were 8 to 9 yr old), onset of deafness (all prelingually deaf), absence of other identified handicapping conditions, age at implant (all before or shortly after their 5th birthday) and family characteristics (English speaking families and parents with normal hearing). The conclusions may be appropriately generalized to children who share or approximate these characteristics. The group was geographically and educationally diverse. Participants came from 33 different states and five Canadian provinces. They represented both public and private schools, mainstream and special education classes and educational programs ranging from exclusively oral emphasizing spoken language skills to total communication programs emphasizing sign language. Thus, the results reported are not attributable to any particular center or type of rehabilitation program.

Epilogue: Factors Contributing to Long-Term Outcomes of Cochlear Implantation in Early Childhood

Objectives: This report focuses on how speech perception, speech production, language, and literacy performance in adolescence are influenced by a common set of predictor variables obtained during elementary school in a large group of teenagers using cochlear implants (CIs). Design: Time-lag analyses incorporating seven common predictor variables associated with the elementary school test period were evaluated. The elementary school-age variables included five contributors across the performance domains: gender, performance intelligence quotient, family size, socioeconomic status, and duration of deafness (operationally defined as the time period between the age of implantation and the onset of deafness). Regression analyses then examined how communication mode in early elementary grades influenced skills exhibited in high school and how this influence was mediated by information capacity of immediate memory. Results: High correlations occurred between outcome measures collected at CI-E session and similar measures collected at CI-HS (values ranging from 0.75 to 0.83), indicating that the relative standing of individuals on these outcomes is highly stable over time. The best performers in elementary grades exhibit the best outcomes in high school, and early difficulties tend to persist throughout the elementary and high school years. The most highly related outcome areas were language and reading/literacy (values ranging from 0.74 to 0.88). These skills seem closely linked, and CI children who demonstrate the best vocabulary and syntax skills in elementary grades achieved the highest literacy performance in high school. Speech perception and speech production skills are also highly correlated with one another (r = 0.69 to 0.87), suggesting that the most direct result of improved auditory input from a CI is the childs ability to produce intelligible speech. The lowest correlations are observed between reading/literacy and speech perception (r = 0.30 to 0.54) or speech production (values ranging from 0.31 to 0.58). CI-E verbal rehearsal speed is an independent and powerful predictor of each early performance outcome, accounting for between 13% and 30% of the variance in early outcomes above and beyond that accounted for by gender, family size, socioeconomic status, performance intelligence quotient, duration of deafness, and the CI-E sign enhancement ratio. Group mean scores for language, reading, and social adjustment were generally within an SD of normative samples of typically developing age-mates with normal hearing. Conclusions: Use of sign to enhance spoken communication negatively influenced verbal rehearsal speed, which was a strong predictor of all early outcomes, which in turn strongly influenced later outcomes. These analyses suggest that early communication mode exerts a powerful influence on early outcomes that persist into later years. Speech perception, speech intelligibility, language, literacy, and psychosocial adjustment far exceeded that reported for similar groups before the advent of CI technology.

The effect of GJB2 allele variants on performance after cochlear implantation.

Objectives/Hypothesis It has been hypothesized that etiology of hearing loss may serve as an independent variable in performance after cochlear implantation. To test this hypothesis, the authors identified pediatric cochlear implant recipients with gap junction protein β2 (GJB2)–related deafness. The study examines performance outcomes associated with GJB2 deafness‐causing allele variants.

SPEECH AND LANGUAGE ACQUISITION IN YOUNG CHILDREN AFTER COCHLEAR IMPLANTATION

Auditory and speech intelligibility scores of 22 prelingually profoundly deaf children who had used cochlear implants for between 1 and 7 years in an intensive auditory/oral educational program greatly exceeded those previously obtained from similar samples of deaf children using hearing aids. Half of the children obtained language quotient scores within the average range for normal-hearing children and the majority obtained reading quotients within 80% of normal levels. Normal levels of language and reading development were associated with early implantation and open set speech perception.

Changing expectations for children with cochlear implants

Seventeen students with cochlear implants who were between 5 and 11 years of age and attended the Moog Center for Deaf Education school program were tested just before exiting the program. The Moog program is an intensive oral program that provides very focused instruction in spoken language and reading. Children leave the program when they are ready for a mainstream setting or when they are 11 years of age, whichever comes first. All of the children demonstrated open-set speech perception ranging from 36% to 100%. On a test of speech intelligibility, all students scored 90% or better. On language and reading tests, compared with the performance of normal-hearing children their age, more than 65% scored within the average range for language and more than 70% scored within the average range for reading. These data demonstrate what is possible for deaf children who benefit from a combination of a cochlear implant and a highly focused oral education program.