A.M.J. Vermeulen

Predictors of Spoken Language Development Following Pediatric Cochlear Implantation

Objectives: Although deaf children with cochlear implants (CIs) are able to develop good language skills, the large variability in outcomes remains a significant concern. The first aim of this study was to evaluate language skills in children with CIs to establish benchmarks. The second aim was to make an estimation of the optimal age at implantation to provide maximal opportunities for the child to achieve good language skills afterward. The third aim was to gain more insight into the causes of variability to set recommendations for optimizing the rehabilitation process of prelingually deaf children with CIs. Design: Receptive and expressive language development of 288 children who received CIs by age five was analyzed in a retrospective multicenter study. Outcome measures were language quotients (LQs) on the Reynell Developmental Language Scales and Schlichting Expressive Language Test at 1, 2, and 3 years after implantation. Independent predictive variables were nine child-related, environmental, and auditory factors. A series of multiple regression analyses determined the amount of variance in expressive and receptive language outcomes attributable to each predictor when controlling for the other variables. Results: Simple linear regressions with age at first fitting and independent samples t tests demonstrated that children implanted before the age of two performed significantly better on all tests than children who were implanted at an older age. The mean LQ was 0.78 with an SD of 0.18. A child with an LQ lower than 0.60 (= 0.78−0.18) within 3 years after implantation was labeled as a weak performer compared with other deaf children implanted before the age of two. Contralateral stimulation with a second CI or a hearing aid and the absence of additional disabilities were related to better language outcomes. The effect of environmental factors, comprising multilingualism, parental involvement, and communication mode increased over time. Three years after implantation, the total multiple regression model accounted for 52% of the variance in receptive language scores and 58% of the variance in expressive language scores. Conclusions: On the basis of language test scores of this large group of children, an LQ of 0.60 or lower was considered a risk criterion for problematic language development compared with other deaf children using CIs. Children attaining LQs below 0.60 should be monitored more closely and perhaps their rehabilitation programs should be reconsidered. Improved language outcomes were related to implantation under the age of two, contralateral stimulation, monolingualism, sufficient involvement of the parents, and oral communication by the parents. The presence of an additional learning disability had a negative influence on language development. Understanding these causes of variation can help clinicians and parents to create the best possible circumstances for children with CIs to acquire language.

The relation between age at the time of cochlear implantation and long-term speech perception abilities in congenitally deaf subjects

The issue of whether an upper age limit should be set for cochlear implantation in congenitally deaf subjects has often been debated. To gain more insight, the speech perception abilities were analyzed of 12 congenitally deaf subjects whose age at the time of cochlear implantation ranged from 4 to 33 years. Subjects implanted during adulthood only showed progress during the first few months after the speech processor had been fitted and their long-term results were poor compared to those of children implanted early in life. This latter group showed steady improvement over the whole evaluation period. The present results support the notion that the earlier in life implantation is performed, the better the development of speech perception. Based on the progress-over-time profiles and data on actual daily use of the cochlear implant, it can be suggested that implantation of congenitally deaf subjects during or after puberty offers only limited benefit.

Effect of Pediatric Bilateral Cochlear Implantation on Language Development

OBJECTIVE To examine spoken language outcomes in children undergoing bilateral cochlear implantation compared with matched peers undergoing unilateral implantation. DESIGN Case-control, frequency-matched, retrospective cross-sectional multicenter study. SETTING Two Belgian and 3 Dutch cochlear implantation centers. PARTICIPANTS Twenty-five children with 1 cochlear implant matched with 25 children with 2 cochlear implants selected from a retrospective sample of 288 children who underwent cochlear implantation before 5 years of age. INTERVENTION Cochlear implantation. MAIN OUTCOME MEASURES Performance on measures of spoken language comprehension and expression (Reynell Developmental Language Scales and Schlichting Expressive Language Test). RESULTS On the receptive language tests (mean difference [95% CI], 9.4 [0.3-18.6]) and expressive language tests (15.7 [5.9-25.4] and 9.7 [1.5-17.9]), children undergoing bilateral implantation performed significantly better than those undergoing unilateral implantation. Because the 2 groups were matched with great care on 10 auditory, child, and environmental factors, the difference in performance can be mainly attributed to the bilateral implantation. A shorter interval between both implantations was related to higher standard scores. Children undergoing 2 simultaneous cochlear implantations performed better on the expressive Word Development Test than did children undergoing 2 sequential cochlear implantations. CONCLUSIONS The use of bilateral cochlear implants is associated with better spoken language learning. The interval between the first and second implantation correlates negatively with language scores. On expressive language development, we find an advantage for simultaneous compared with sequential implantation.

Three-year follow-up of children with postmeningitic deafness and partial cochlear implant insertion.

Objectives:  To evaluate the long‐term outcome of children with postmeningitic deafness and partial insertion of the Nucleus electrode array, and to compare their speech perception performance with that of children with full insertion of the electrode array.

Oral language acquisition in children assessed with the Reynell Developmental Language Scales.

Oral language development of ten children, prelingually deafened by meningitis, was assessed with a Dutch version of the Reynell Developmental Language Scales. The test was administered pre-operatively and at regular intervals after implantation. The average rate of language development between two consecutive evaluations was computed. This rate was defined as the quotient of the increase of the language age and the increase of the chronological age between the evaluations. A normal language development has a rate of 1; this means 12 months language development in 12 months time. In case of language retardation the rate of language development is less than 1. The rate of receptive language development showed a gradual increase. In the interval between 12 and 24 months of implant use the ratio was 0.9. This implies a language development that is quite similar with the development in normal hearing children. The rate of expressive language development showed a fast improvement in the period between 6 and 12 months after implantation, up to 1.4. If this rate of development continues the children with C.I. will catch up with their normal hearing peers.

Verbal cognition in deaf children using cochlear implants: effect of unilateral and bilateral stimulation

The aim of this study is to assess the role of bilateral/bimodal device use in auditory speech perception in complex listening situations and long-term verbal cognition in deaf children using cochlear implants (CIs). Two groups of children are compared (unilateral and bilateral device users) concerning vocabulary, speech perception at conversational level and in complex listening situations, and verbal cognition. In this retrospective study, we collected data of 37 deaf children with normal learning potential of whom 16 were unilateral CI users and 21 were bilateral device users (9 with a bimodal fitting and 12 with bilateral CIs). We came to the conclusion that deaf children who use bilateral devices have the opportunity to develop good speech perception skills in complex listening conditions. These abilities enable at least some of the children to develop age-equivalent verbal cognition skills.

School performance and wellbeing of children with CI in different communicative-educational environments

OBJECTIVES This study aimed to evaluate the long term effects of CI on auditory, language, educational and social-emotional development of deaf children in different educational-communicative settings. METHODS The outcomes of 58 children with profound hearing loss and normal non-verbal cognition, after 60 months of CI use have been analyzed. At testing the children were enrolled in three different educational settings; in mainstream education, where spoken language is used or in hard-of-hearing education where sign supported spoken language is used and in bilingual deaf education, with Sign Language of the Netherlands and Sign Supported Dutch. Children were assessed on auditory speech perception, receptive language, educational attainment and wellbeing. RESULTS Auditory speech perception of children with CI in mainstream education enable them to acquire language and educational levels that are comparable to those of their normal hearing peers. Although the children in mainstream and hard-of-hearing settings show similar speech perception abilities, language development in children in hard-of-hearing settings lags significantly behind. Speech perception, language and educational attainments of children in deaf education remained extremely poor. Furthermore more children in mainstream and hard-of-hearing environments are resilient than in deaf educational settings. Regression analyses showed an important influence of educational setting. CONCLUSIONS Children with CI who are placed in early intervention environments that facilitate auditory development are able to achieve good auditory speech perception, language and educational levels on the long term. Most parents of these children report no social-emotional concerns.

Benefits of simultaneous bilateral cochlear implantation on verbal reasoning skills in prelingually deaf children

BACKGROUND Impaired auditory speech perception abilities in deaf children with hearing aids compromised their verbal intelligence enormously. The availability of unilateral cochlear implantation (CI) auditory speech perception and spoken vocabulary enabled them to reach near ageappropriate levels. This holds especially for children in spoken language environments. However, speech perception in complex listening situations and the acquisition of complex verbal skills remains difficult. Bilateral CI was expected to enhance the acquisition of verbal intelligence by improved understanding of speech in noise. METHODS This study examined the effect of bilateral CI on verbal intelligence of 49 deaf children (3;5-8;0 years). Relations between speech perception in noise, auditory short-term memory and verbal intelligence were analysed with multiple linear regressions. In addition, the interaction of educational setting, mainstream or special, on these relations was analysed. RESULTS Children with bilateral CI obtained higher scores on verbal intelligence. Significant associations were present between speech perception in noise, auditory short-term memory and verbal intelligence. CONCLUSION Children with simultaneous bilateral CIs showed better speech perception in noise than children with unilateral CIs, which mediated by the auditory short-term memory capacity, enhanced the ability to acquire more complex verbal skills for BICI children in mainstream education.