A comparison of language achievement in children with cochlear implants and children using hearing aids

Childhood Development after Cochlear Implantation (CDaCI) study: design and baseline characteristics

Children with severe to profound sensorineural hearing loss face communication challenges that influence language, psychosocial and scholastic performance. Clinical studies over the past 20 years have supported wider application of cochlear implants in children. The Childhood Development after Cochlear Implantation (CDaCI) study is the first longitudinal multicentre, national cohort study to evaluate systematically early cochlear implant (CI) outcomes in children. The objective of the study was to compare children who have undergone cochlear implantation, with similarly aged hearing peers across multiple domains, including oral language development, auditory performance, psychosocial and behavioural functioning, and quality of life. The CDaCI study is a multicentre national cohort study of CI children and normal hearing (NH) peers. Eligibility criteria include informed consent, age less than 5 years, pre- or post-lingually deaf, developmental criteria met, commitment to educate the child in English and bilateral cochlear implants. All children had a standardised baseline assessment that included demographics, hearing and medical history, communication history, language measures, cognitive tests, speech recognition, an audiological exam, psychosocial assessment including parent-child videotapes and parent reported quality of life. Follow-up visits are scheduled at six-month intervals and include a standardised assessment of the full battery of measures. Quality assurance activities were incorporated into the design of the study. A total of 188 CI children and 97 NH peers were enrolled between November 2002 and December 2004. The mean age, gender and race of the CI and NH children are comparable. With regard to parental demographics, the CI and NH children's families are statistically different. The parents of CI children are younger, and not as well educated, with 49% of CI parents reporting college graduation vs. 84% of the NH parents. The income of the CI parents is also lower than the NH parents. Assessments of cognition suggest that there may be baseline differences between the CI and NH children; however the scores were high enough to suggest language learning potential. The observed group differences identified these baseline characteristics as potential confounders which may require adjustment in analyses of outcomes. This longitudinal cohort study addresses questions related to high variability in language outcomes. Identifying sources of that variance requires research designs that: characterise potential predictors with accuracy, use samples that adequately power a study, and employ controls and approaches to analysis that limit bias and error. The CDaCI study was designed to generate a more complete picture of the interactive processes of language learning after implantation.

The use and reliability of Tait video analysis in assessing preverbal language skills in profoundly deaf and normally hearing children under 12 months of age

BACKGROUND

Assessment measures in evaluating preverbal skills and their progress in very young deaf children are lacking. However, their importance is highlighted by the recent trend of implanting children under 1 year of age. Tait video analysis is a technique for assessing preverbal communication behaviours in very young children with hearing impairment and has been found to be strongly related to speech discrimination and intelligibility outcomes post-implantation.

AIM

To assess feasibility and inter-user reliability of Tait video analysis in assessing preverbal communication skills in children under 1 year of age.

MATERIAL AND METHODS

Ten children (five profoundly deaf and five normally hearing) under 1 year of age were assessed by Tait video analysis. Three observers analysed the samples independently, according to the established protocol.

RESULTS

There was complete agreement on 305 judgements and 8 discrepancies between observers over all the measures. Four of the discrepancies occurred in the samples of deaf children and four in the normally hearing samples. Statistical analysis revealed that the correlation coefficients between the different observers were extremely high ranging from 0.94 to 1 (perfect agreement). All of them were found to be statistically significant (p<0.01).

CONCLUSION

The very high rate of inter-observer reliability suggests that the video recordings of children under 12 months can be scored consistently, and Tait video analysis is therefore a valid method of monitoring the development of vocal and auditory preverbal skills in very young deaf children, either following cochlear implantation or using acoustic hearing aids.

Reading comprehension of deaf children with cochlear implants

The reading comprehension and visual word recognition in 50 deaf children and adolescents with at least 3 years of cochlear implant (CI) use were evaluated. Their skills were contrasted with reference data of 500 deaf children without CIs. The reading comprehension level in children with CIs was expected to surpass that in deaf children without implants, partly via improved visual word recognition. Reading comprehension scores of children with implants were significantly better than those of deaf children without implants, although the performance in implant users was substantially lagging behind that in hearing children. Visual word recognition was better in children with CIs than in children without implants, in secondary education only. No difference in visual word recognition was found between the children with CIs and the hearing children, whereas the deaf children without implants showed a slightly poorer performance. The difference in reading comprehension performance of the deaf children with and without CIs remained present when visual word recognition was controlled for. This indicates that other reading-related skills were also contributing to the improved reading comprehension skills of deaf children with CIs.

Measuring health-related quality of life after pediatric cochlear implantation: a systematic review

OBJECTIVE

The measurement of health-related quality of life (HRQL) in children presents conceptual and methodological challenges owing to the multidimensionality of the required information and limitations in patient self-report. HRQL results provide a broad measure of treatment impact from the patient and family perspective and are crucial to guiding clinical and policy decisions. The objective of this study was to evaluate how HRQL in children with cochlear implants has been measured in published studies in order to draw conclusions that could inform future investigations of this area of clinical research.

METHODS

We searched PubMed, EMBASE, CINAHL, PsychoInfo, and Web of Science databases using a defined search string and hand-searched reference lists of relevant articles and personal files. Retrieved citations were reviewed in two stages, a title and abstract screen followed by review of the full-length article. Inclusion criteria for studies were: (1) original peer-reviewed research article; (2) enrolled subjects <18 years old with cochlear implants; (3) use of a HRQL instrument that incorporated components of physical, mental, and social health; and (4) in English. Data from full-length articles were extracted by a single-investigator.

RESULTS

We retrieved 671 citations with our search strategy, and 10 citations were found to be eligible for inclusion. All studies used a cross-sectional design, and three types of HRQL instruments were used: generic questionnaires, ad hoc instruments designed specifically for the purposes of the study, and the parents views and experiences with pediatric CI questionnaire. Heterogeneity in study design and instruments prevented a quantitative, meta-analysis of the data.

CONCLUSIONS

Studies that used well-validated, generic HRQL instruments supported conclusions that were less subject to potential bias from the perspective of the clinician investigator. Most studies did not use well-defined cohorts with respect to age at implantation and duration of implant use, and conclusions in these studies were also subject to potential bias. No well-validated, deafness-specific HRQL instruments are currently available. Future research should be done with existing, generic HRQL instruments and with strict study inclusion criteria. Suggested generic HRQL instruments are discussed.

Longitudinal improvements in communication and socialization of deaf children with cochlear implants and hearing aids: evidence from parental reports

BACKGROUND

Research has shown that the cochlear implant may improve deaf children's speech and communication skills. However, little is known about its effect on children's ability to socialize with hearing peers.

METHODS

Using a standardized psychological measure completed by parents and a longitudinal design, this study examined the development of communication, socialization, and daily living skills of children who used hearing aids or cochlear implants for an average of 11 and 6 years, respectively.

RESULTS

Results show that children with cochlear implants, who were more delayed than children with hearing aids at the outset, made significant progress over time. Children with both devices achieved age-appropriate development after years of hearing aid or cochlear implant use.

CONCLUSIONS

The pattern of results suggests that cochlear implants may be effective in improving deaf children's communication and social skills.

Long-Term Functional Outcomes and Academic-Occupational Status in Implanted Children After 10 to 14 Years of Cochlear Implant Use

OBJECTIVES

To assess a group of consecutively implanted children over 10 years after implantation with regard to implant device use and function, speech perception, and speech intelligibility outcomes; and to document current academic or occupational status.

STUDY DESIGN

A prospective longitudinal study assessing device function, device use, speech perception, speech intelligibility, and academic/occupational status of implanted deaf children.

SETTING

Pediatric tertiary referral center for cochlear implantation.

METHODS

The auditory performance and speech intelligibility development of 30 profoundly deaf children were rated before cochlear implantation and at 5 and 10 years after implantation using the Categories of Auditory Performance and the Speech Intelligibility Rating. The academic and/or occupational status of the participants after 10 years of implant experience was documented. All children received a Nucleus multichannel cochlear implant between the ages of 2.5 and 11 years (mean age at implantation, 5.2 yr). Implant experience ranged from 10 to 14 years of use.

RESULTS

After 10 years of implant experience, 26 subjects (87%) reported that they always wore their device; 2 subjects (7%), frequently; and 1 subject (3%), occasionally. Only one child had discontinued use of his device. After 10 years of implant use, 26 (87%) of the children understood a conversation without lip reading and 18 (60%) used the telephone with a familiar speaker. Ten years after implantation, 23 (77%) of the subjects used speech intelligible to an average listener or a listener with little experience of a deaf person's speech. One-third to one-half of the implanted children continued to demonstrate improvements at 5 to 10 years of implant use. Of the 30 implanted children, 8 (26.7%) experienced nine device failures. The length of time from identification of the first faulty electrode to reimplant surgery ranged from 2 weeks to 5.5 years, as several failures were gradual or intermittent. However, all children were successfully reimplanted. At the end of the study (10-14 yr after implantation), 19 subjects were in secondary school for children aged 11 to 16 years: 6 were in mainstream schools, 7 were in specialist hearing-impaired units attached to a mainstream secondary school, and 6 were in schools for the deaf. Of the remaining 11 subjects, 4 were in college studying vocational subjects, 2 were in a university studying for a bachelor's degree, 3 were working full-time, 1 was working and going to a university part-time, and 1 was a full-time mother of two young children.

CONCLUSION

All but 1 of the 30 implanted children continue using their devices 10 to 14 years after implantation, showing significant progress in speech perception and production. Device failure was frequent, but successful reimplantation occurred in all cases. One-third to one-half of the implanted children in this study continued to demonstrate improvements at 5 to 10 years of implant use. All children are studying or working and are actively involved in their local communities. The results suggest that cochlear implantation provides long-term communication benefit to profoundly deaf children that does not plateau for some subjects even after reimplantation. This study further indicates that cochlear implant centers need the structure and funding to provide long-term support, counseling, audiologic follow-up, rehabilitation, and device monitoring to implanted children.

The effect of age at cochlear implant initial stimulation on expressive language growth in infants and toddlers

This study examined the growth of expressive language skills in children who received cochlear implants (CIs) in infancy. Repeated language measures were gathered from 29 children who received CIs between 10 and 40 months of age. Both cross-sectional and growth curve analyses were used to assess the relationship between expressive language outcomes and CI experience. A beneficial effect of earlier implantation on expressive language growth was found. Growth curve analysis showed that growth was more rapid in children implanted as infants than those implanted as toddlers. Age at initial stimulation accounted for 14.6% of the variance of the individual differences in expressive language growth rates.

Spoken Word Recognition in Children With Cochlear Implants: A Five-Year Study on Speakers of a Tonal Language

OBJECTIVES

To study the effects of age at implantation and duration of implant use on the performance of spoken word recognition of pediatric cochlear implantees in a tonal language setting over a period of 5 years.

DESIGN

Sixty-four children, given implants between the ages 1:01 and 14:09 (years:months), were divided into three age groups. They were tested on open-set word recognition ability at seven time intervals from before surgery to 5 years after surgery. Analyses of variance with repeated measurements were used to examine the effect of their age at implantation and the duration of implant use.

RESULTS

Duration of implant experience was significant in spoken word recognition across the three age groups (p < 0.01). Children given implants below the age of 3 years caught up with the performance of the older children at 12 months after implantation. The difference in score reached statistical significance at 2 and at 3 years after surgery (p = 0.03, p = 0.00).

CONCLUSIONS

The performance of Cantonese-speaking children was similar to that of English-speaking children in that better outcomes were associated with longer implant experience as well as when implantation occurred at a younger age. The children implanted before the age of 3 and who had an implant experience of more than 2 years outperformed the children who were given implants after the age of 6 and also sustained these higher scores throughout 5 years of postimplant testing.

Cochlear implants: 100 pediatric case conversions from the body worn to the nucleus esprit 22 ear level speech processor

OBJECTIVE

To assess performance of Nucleus 22 mini system pediatric users converted from the Spectra 22 body-worn to the ESPrit 22 ear-level speech processor using aided thresholds and speech discrimination measures before and after the conversion.

STUDY DESIGN

Spectra 22 body-worn speech processor users were chosen using preselection criteria (stable map, ability to report on the quality of the signal, no device problems). The subjects underwent tuning, map conversion, fitting of the ESPrit 22, and aided soundfield threshold and speech discrimination testing.

SUBJECTS

The first 100 consecutive conversions are analyzed in this study. Fifty children (50%) were female, and 50 (50%) were male. The average age at implantation was 4.6 years (median 4.3 years, range 1.7 to 11 years). The average age of fitting the ear level speech processor was 11.1 years (median 11 years, range 6.2 to 18.2 years).

SETTING

Tertiary referral pediatric cochlear implant center in the United Kingdom.

RESULTS

Of the 100 fittings attempted, all Spectra 22 maps could to be converted for use in the ESPrit 22. Of these 100 fittings, 44 were straightforward with no adjustment to map parameters being required, and 56 needed rate reductions and other map adjustments to achieve the conversion. The difference of the mean thresholds before and after the conversion did not exceed 2 dB across the frequencies studied (0.5-4 kHz). In 95% of the cases, the differences were less than 9 dB(A). With regard to speech discrimination testing, the mean threshold before the conversion was 53.4 dB and after the conversion 52.7 dB. Of the 100 conversions, only five children stopped using the ESPrit 22 despite fitting being achieved.

CONCLUSION

Conversion from the Spectra 22 body worn to the ESPrit 22 ear level speech processor was found to be feasible in all the 100 cases studied. Only a minority (5%) of children chose not to use the ear level speech processor suggesting that children and parents were satisfied from the conversion.

Word Learning in Children Following Cochlear Implantation

An experimental procedure was developed to investigate word-learning skills of children who use cochlear implants (CIs). Using interactive play scenarios, 2- to 5-year olds were presented with sets of objects (Beanie Baby stuffed animals) and words for their names that corresponded to salient perceptual attributes (e.g., "horns" for a goat). Their knowledge of the word-object associations was measured immediately after exposure and then following a 2-hour delay. Children who use cochlear implants performed more poorly than age-matched children with typical hearing both receptively and expressively. Both groups of children showed retention of the word-object associations in the delayed testing conditions for words that were previously known. Our findings suggest that although pediatric CI users may have impaired phonological processing skills, their long-term memory for familiar words may be similar to children with typical hearing. Further, the methods that developed in this study should be useful for investigating other aspects of word learning in children who use CIs.

Speech intelligibility of pediatric cochlear implant recipients with 7 years of device experience

Speech intelligibility of 24 prelingually deaf pediatric cochlear implant (CI) recipients with 84 months of device experience was investigated. Each CI participant's speech samples were judged by a panel of 3 listeners. Intelligibility scores were calculated as the average of the 3 listeners' responses. The average write-down intelligibility score was 71.54% (SD = 29.89), and the average rating-scale intelligibility score was 3.03 points (SD = 1.01). Write-down and rating-scale intelligibility scores were highly correlated (r = .91, p < .001). Linear regression analyses revealed that both age at implantation and different speech-coding strategies contribute to the variability of CI participants' speech intelligibility. Implantation at a younger age and the use of the spectral-peak speech-coding strategy yielded higher intelligibility scores than implantation at an older age and the use of the multipeak speech-coding strategy. These results serve as indices for clinical applications when long-term advancements in spoken-language development are considered for pediatric CI recipients.

Outcomes and achievement of students who grew up with access to cochlear implants

OBJECTIVES/HYPOTHESIS

To provide long-term speech perception and production, educational, vocational, and achievement outcome data for pediatric cochlear implant recipients.

STUDY DESIGN

This is a retrospective study using consecutive referrals of prelingually, profoundly deaf children at the University of Iowa Hospitals and Clinics.

METHODS

Twenty-seven prelingually deaf young adults who received a cochlear implant between the ages of 2 and 12 years participated. Outcome measures included device-use information, perceptual information, reading results for all participants and educational achievement results for 17 of 27 participants, educational placement information/vocational information for all students, as well as a comparison of the child's educational/vocational outcome with that of the parent's educational/vocational outcome.

RESULTS

Speech perception and production scores were highly correlated. Achievement test results indicated that scores were within 1 SD from normative data based on hearing individuals. Over 50% of the college-age eligible students enrolled in college. This initial group of implant users had a nonuse rate of 11% in the first 3 years. Eighty-nine percent of the users maintained full-time use for 7 years, and 71% of this group have maintained full-time use to date.

CONCLUSIONS

This cohort of cochlear implant users compared favorably with their hearing peers on academic achievement measures. Although there was a wide distribution of educational and vocational outcomes, the children tended to follow the educational/vocational patterns of their parents. As age of implantation decreases, it will be important to compare achievement outcomes of this first generation with those of subsequent generations of cochlear implant users.

Examining multiple sources of influence on the reading comprehension skills of children who use cochlear implants

Children with profound deafness are at risk for serious reading difficulties. Multiple factors affect their development of reading skills, including use of cochlear implants. Further, multiple factors influence the overall success that children experience with their cochlear implants. These factors include the age at which they receive an implant, method of communication, vocabulary skills, preoperative residual hearing, and socioeconomic status. Ninety-one children with prelingual and profound hearing impairments who received cochlear implants at varying ages participated in the study. Structural equation modeling confirmed that multiple factors affected young cochlear implant users' reading comprehension skills and that there were significant associations between the predictors of reading comprehension. Pre-implant vocabulary had an indirect positive effect on reading through postimplant vocabulary, which had a direct positive effect on reading. Overall, children with stronger language skills demonstrated stronger reading outcomes. Age at implantation both directly and indirectly, through postimplant vocabulary, affected reading outcomes, and the total effect was large. Children who were younger when they received their implants tended to have higher reading comprehension scores. Socioeconomic status negatively affected reading. Children who used total communication prior to implantation tended to have stronger pre-implant vocabulary scores, but the total effect of pre-implant communication method on children's reading skills was negligible. Research and educational implications are discussed.

Cochlear Implantation Between 5 and 20 Months of Age: The Onset of Babbling and the Audiologic Outcome

OBJECTIVE

The objective of this study was to investigate the onset of prelexical babbling and the audiologic outcome of 10 deaf children who received a cochlear implant (CI) before the age of 20 months.

STUDY DESIGN

A prospective longitudinal observation and analysis.

PATIENTS

Ten congenitally deaf infants implanted at an age between 6 and 18 months.

INTERVENTION

All children received a Nucleus-24 multichannel cochlear implant.

MAIN OUTCOME MEASURES

1) The onset of babbling defined as a) the first appearance of multiple articulatory movements and b) a canonical babbling ratio of.2 or higher; 2) the babbling spurt defined as a sudden increase of babbled utterances; 3) the audiologic outcome defined by the CAP score (Categories of Auditory Performance) and the results of the A[S]E (Auditory Speech Sound Evaluation).

RESULTS

All children started babbling after a short interval of 1 to 4 months after activation of the device so that the onset of babbling in the youngest subjects occurred at a chronologic age comparable to that of normally hearing infants. The outcomes of the different babbling measures correlated significantly with the age of implantation: the earlier the implantation, the closer the results approached the outcomes of normally hearing infants. The children implanted in their first year of life showed a normal CAP development as early as 3 months after implantation. All CI children were able to discriminate phoneme pairs of the A[S]E immediately after the fitting of the device.

CONCLUSIONS

The earlier the implantation took place, the smaller the delay was in comparison with normally hearing children with regard to the onset of prelexical babbling and with regard to auditory performance as measured by CAP.

Cochlear implants in young children

The cochlear implant is best characterized as a device that provides access to the sound environment. The device enables the hearing pathway to respond to environmental and speech sounds, providing informational cues from the surroundings and from others that may escape visual detection. As the developmental effects of a profound hearing loss are multiple, cochlear implants have been applied to ever younger children in an attempt to promote a more normal level of developmental learning through audition. In deafness, transducer elements of the inner ear fail to trigger auditory nerve afferent nerves in the presence of sound input. However, large reserves of afferent fibers exist even in the auditory nerve of a profoundly deaf patient. Furthermore, these nerve fibers retain the ability to respond to prosthetic activation. Through developmental learning in the early, formative years, auditory centers of the brain appear capable of processing information from the implant to provide speech comprehension and oral language development. Multichannel implants have replaced original single channel designs. multichannel devices enable larger percentages of recipients to recognize the spoken word without visual cues because they provide spectral information in addition to temporal and intensity cues. Testing under conditions of auditory (implant)-only input reveals significant open-set speech understanding capabilities in more than 75% of children after three years of device use. The benefit provided by implants may vary with a number of conditions including: hearing history, age of deafness onset, age at implantation, etiology of deafness, linguistic abilities, and the presence of a motivated system of support of oral language development. Patient variables should be given individual consideration in judging candidacy for a cochlear implant and in planning rehabilitative and education services after surgery and activation of the device.

Exploring the language and literacy outcomes of pediatric cochlear implant users

OBJECTIVE

The principal goal of this study was to investigate the relationship between language and literacy (i.e., reading and writing) skills in pediatric cochlear implant users. A peripheral objective was to identify the children's skills that were in need of remediation and subsequently to provide suggestions for remedial programming. It was predicted that the robust language skills often associated with children who have cochlear implant experience would facilitate the development of literacy skills. It was further proposed that the language and literacy skills of pediatric cochlear implant users would approximate the language and literacy skills of children with normal hearing.

DESIGN

Sixteen pediatric cochlear implant users' language and literacy skills were evaluated and then compared with a reference group of 16 age-matched, normal-hearing children. All 32 participants were educated in mainstream classes within the public school system in the Midwest. The "Sentence Formulation" and "Concepts and Directions" subtests of the Clinical Evaluation of Language Fundamentals-3 test were used to evaluate receptive and expressive language skills. Reading comprehension was evaluated with the "Paragraph Comprehension" subtest of the Woodcock Reading Mastery Test. Performance measures for the writing analyses included productivity, complexity and grammaticality measures.

RESULTS

Children with cochlear implants performed within 1 SD of the normal-hearing, age-matched children on measures of language comprehension, reading comprehension and writing accuracy. However, the children with cochlear implants performed significantly poorer than the children with normal hearing on the expressive "Sentence Formulation" subtest. The cochlear implant users also produced fewer words on the written narrative task than did the normal-hearing children, although there was not a significant difference between groups with respect to total words per clause. Furthermore there was a strong correlation between language performance and reading performance, as well as language performance and total words produced on the written performance measure for the children using cochlear implants.

CONCLUSIONS

The results of this study suggest that the language skills of pediatric cochlear implant users are related to and correlated with the development of literacy skills within these children. Consequently, the performance of the cochlear implant users, on various language and literacy measures, compared favorably to an age-matched group of children with normal hearing. There were significant differences in the ability of the cochlear implant users to correctly utilize grammatical structures such as conjunctions and correct verb forms when they were required to formulate written and oral sentences. Given this information, it would be appropriate for their educational or remedial language programs to emphasize the use and development of these structures.

Using SNAP Dragons to monitor narrative abilities in young deaf children following cochlear implantation

OBJECTIVE

To assess the narrative abilities of young deaf children before cochlear implantation and 1 and 2 years following implantation, and to explore possible changes in the implanted children's preferred mode of communication in the narrative abilities task.

STUDY DESIGN

Prospective longitudinal study assessing the narrative abilities of young deaf children before and after cochlear implantation.

SETTING

Pediatric tertiary referral center for cochlear implantation.

PATIENTS AND METHODS

The narrative abilities of 35 young profoundly deaf children were assessed before implantation and 1 and 2 years following implantation using the Stories/Narratives Assessment Procedure. Children with age at implantation less than 6 years were included in the study (mean age at implantation was 3.5 years; range 1.4-5.9 years). All children were filled with the Nucleus multichannel cochlear implant system. With respect to their communication modes, they came from a wide range of backgrounds and all children were encouraged to use their preferred mode of communication during the narrative task.

RESULTS

The data showed that there was a statistically significant increase in narrative abilities across the three data points (P<0.001). Before receiving the implant, children were mostly in the pre-structural, receptive stages and could at most label or comment on the pictures (median narrative stage 2). By the 2-year interval, children were mostly using one or two categories or one complete episode with spontaneous retelling (median narrative stage 4). Although children were not pressured to use any particular communication mode, a shift to speech was found following implantation and this was statistically significant (P<0.001).

CONCLUSION

Young implanted deaf children showed a significant progress in their narrative abilities through time and a significant shift in the predominant mode of communication towards more speech orientated communication modes following cochlear implantation.

Beginning to communicate after cochlear implantation: oral language development in a young child

This longitudinal case study examined the emergence of a wide range of oral language skills in a deaf child whose cochlear implant was activated at 20 months. The main purposes of this study were to determine "Hannah's" rate of spoken language development during her second to fourth year of implant experience and to estimate the efficiency of her progress by comparing her performance to that of typically developing children. Mother-child interactions were also examined to determine changes in Hannah's communication competence. Normal or above-normal rates of development were observed in the following areas: (a) decreased production of nonwords, (b) increased receptive vocabulary, (c) type-token ratio, (d) regular use of word combinations, and (e) comprehension of phrases. Below-normal rates of development were observed in the following areas: (a) speech intelligibility, (b) number of word types and tokens, and (c) mean length of utterance in morphemes. Analysis of parent-child interactions showed a large increase in responses to questions during the third year of implant use. Data from Hannah's first post-implantation year (D. J. Ertmer & J. A. Mellon, 2001) indicated that some early language milestones were attained quite rapidly (e.g., canonical vocalizations and emergence of first word combinations). In contrast, the current study revealed that progress had slowed for related, but more advanced skills (e.g., production of intelligible speech and consistent use of word combinations). These changes in rate of development suggest that any advantages for language learning due to Hannah's advanced maturity (or other unknown factors) decreased with time and increasing linguistic complexity.

Language skills of children with early cochlear implantation

OBJECTIVE

This study investigated factors contributing to the comprehension and production of English language by children with prelingual deafness after 4 to 7 yr of multichannel cochlear implant use. The analysis controlled for the effects of child and family characteristics so that educational factors most conducive to maximum implant benefit could be identified.

DESIGN

A battery of language tests were administered to 181 8- and 9 yr-old children from across the United States and Canada who received a cochlear implant by age 5. Tests of comprehension, verbal reasoning, narrative ability and spontaneous language production were administered either in speech and sign or in the child's preferred communication mode. These constituted the Total Language measures. Spoken Language measures were derived from a speech-only language sample. Type and amount of educational intervention since implantation constituted the independent variables. Characteristics of the child and the family were considered intervening variables. A series of multiple regression analyses determined the amount of variance in Total Language and Spoken Language ability accounted for by the intervening variables and the amount of additional variance attributable to the independent variables.

RESULTS

More than half of the children (with performance intelligence quotients in the average range) exhibited language skills that were similar to those of hearing 8 to 9 yr olds on measures of verbal reasoning, narrative ability, utterance length, and lexical diversity. Significant predictors of language ability were similar for Total and for Spoken Language outcomes and included greater nonverbal intelligence, smaller family size, higher socio-economic status and female gender. Age at receiving an implant did not affect language outcome. After the variance due to these variables was controlled, the primary rehabilitative factors associated with linguistic outcome were amount of mainstream class placement and an educational emphasis on speech and auditory skills.

CONCLUSIONS

Use of a cochlear implant has had a dramatic impact on the linguistic competence of profoundly hearing-impaired children. More than half of the children in this sample with average learning ability produced and understood English language at a level comparable with that of their hearing age mates. Such mature language outcomes were not typical of children with profound hearing loss who used hearing aids. Use of a visual (i.e., sign) language system did not provide the linguistic advantage that had been anticipated. Children educated without use of sign exhibited a significant advantage in their use of narratives, the breadth of their vocabulary, in their use of bound morphemes, in the length of their utterances and in the complexity of the syntax used in their spontaneous language. An oral educational focus provided a significant advantage for both spoken and total language skills.

Background and educational characteristics of prelingually deaf children implanted by five years of age

PURPOSE

This study documents child, family and educational characteristics of a large representative sample of 8- to 9-yr-old prelingually deaf children who received a cochlear implant by 5 yr of age. Because pre-existing factors such as the child's gender, family characteristics, additional handicaps, age at onset of deafness and at implant, may affect postimplant outcomes, these variables must be accounted for before the impact of educational factors on performance with an implant can be adequately determined. Classroom variables that may affect postimplant outcomes include placement in public or private, mainstream or special education, oral or total communication environments. Other intervention variables include type and amount of individual therapy, experience of the therapist and parent participation in therapy. Documenting these characteristics for a large representative sample of implanted children can provide clinicians and researchers with insight regarding the types of families who sought early cochlear implantation for their children and the types of educational programs in which they placed their children after implantation. It is important to undertake studies that control for as many of these factors as possible so that the relative benefits of specific educational approaches for helping children to get the most benefit from their cochlear implant can be identified.

METHOD

Over a 4-yr period, 181 children from across the US and Canada, accompanied by a parent, attended a cochlear implant research camp. Parents completed questionnaires in which they reported the child's medical and educational history, characteristics of the family, and their participation in the child's therapy. The parent listed names and addresses of clinicians who had provided individual speech/language therapy to the child and signed permission for these clinicians to complete questionnaires describing this therapy.

RESULTS

To the extent that this sample is representative of those families seeking a cochlear implant for their child, especially during the initial period of device availability, this population can be characterized as follows. Most parents had normal hearing, were of majority (white) ethnicity and had more education and higher incomes than the general population. The families tended to be intact with both a mother and a father who involved their hearing-impaired child in family activities on a regular basis. The children were enrolled in the full range of educational placements available across the United States and Canada. Fairly even distributions of children from public and private schools, special education and mainstream classes and oral and total communication methodologies were represented. Educational placement changed as children gained increased experience with a cochlear implant. They received an increased emphasis on speech and auditory skills in their classroom settings and tended to move from private school and special education settings to public school and mainstream programs. These data support the position that early cochlear implantation is a cost effective procedure that allows deaf children to participate in a normal school environment with hearing age mates.

Factors associated with development of speech production skills in children implanted by age five

OBJECTIVE

This study investigated speech production outcomes and the factors influencing the outcomes in children who had 4 to 6 yr of experience with a multichannel cochlear implant. Production variables examined included speech intelligibility, accuracy of consonant and vowel production, percentage of plosives and fricatives produced, duration of sentences, percentage of time involved in communication breakdowns during a communication sample, and responses to a speech usage questionnaire.

DESIGN

181 children between the ages of 8 and 9 yr who received a multichannel cochlear implant before age 5 yr participated as subjects. Independent variables were the amount and type of educational intervention and intervening variables were distributed across child, family and implant characteristics. Multiple regression analyses provided a measure of the amount of variance associated with speech production skills accounted for by the intervening and independent variables.

RESULTS

Performance for the key words in the speech intelligibility measured averaged 63.5% for the group of children. Accuracy of phoneme production was higher for consonants (68.0%) than for vowels (61.6%) for the group. More plosives were present for acoustic analyses (91.6%) than were fricatives (78.4%). Duration for the speech intelligibility sentences averaged 2572.3 msec. Communication breakdowns occurred on average 14.5% of the time involved in a language sample. Significant predictors of high levels of oral communication skills included higher nonverbal intelligence, gender, longer use of SPEAK processing strategy, a fully active electrode array, greater dynamic range, and greater growth of loudness. The primary rehabilitative factors contributing to high levels of oral communication were an emphasis on oral-aural communication and classrooms that emphasized dependence on speech and listening.

CONCLUSIONS

Speech production performance in children with cochlear implants is influenced by nonverbal intelligence, gender, implant characteristics including the length of time using the newest speech processing strategies, and educational programs emphasizing oral-aural communication. Factors previously thought to be major contributors to speech production performance, such as age of onset of deafness and age of implantation, did not appear to play significant roles in predicting levels of speech production performance.

Parent interaction course in order to enhance communication skills between parents and children following pediatric cochlear implantation

OBJECTIVE

To assess the effect of a parent interaction training course on the communication skills of parents of young implanted children. The training course was designed to help parents to be less controlling in their interactions with their deaf children and to facilitate the development of spoken language.

STUDY DESIGN

Prospective study comparing the communication skills of parents of deaf children fitted with cochlear implants before and after a parent interaction training course.

SETTING

Pediatric tertiary referral center for cochlear implantation.

METHODS

Video samples were taken of parents interacting with their children 1 month before the course (ranging from 15 days to 2 months) and after the course (ranging from 15 days to 1 month). Video samples were then transcribed orthographically and parents' turns in the interaction were assigned to one of two categories: (a) initiations--the parent initiates conversation or introduces a new topic and (b) responses--the parent responds to the child's previous turn. 12 months after completion of the course, the process was repeated in order to establish the relative permanence of changes in behavior.

HYPOTHESIS

The parents' turns would shift from a predominance of initiations to a predominance of responses as a result of attendance on the course. This would demonstrate that the parents were less controlling of their children in communication and were exhibiting more contingent behavior--responding to their child's initiations rather than expecting the child to respond to theirs.

PATIENTS

The study involved 17 parents of 11 implanted children. The mean age at implantation was 4 years (range: 2.2-6.3 years). The implant experience of the children ranged from 2 to 23 months at the time of the study. All children used total communication.

RESULTS

The post-course initiations were half those of the pre-course ones (median from 14 decreased to 7) and the responses were almost double following the course (median from 8 increased to 14). Both differences were statistically significant (P < 0.05). 12 months after the course, the responses score remained high with a median score of 16.5. However, a slight but significant increase in the initiation scores was also noted (median from 7 to 8.5). Parental satisfaction of the course was found to be high as no families failed to attend on any of the occasions despite the great distances some of them had to travel.

CONCLUSION

The format of the parent interaction training course was found to be highly acceptable to the parents and the components covered proved to be effective in promoting positive changes in parental communication behavior. Clinicians need to provide a responsive environment for implanted deaf children and help others to do the same. The training course provided a very useful forum to share insights and skills and to evaluate ways of enhancing the communication between parents and children following cochlear implantation.

Paediatric cochlear implantation: prosthetic hearing and language development

CONTEXT

Cochlear implantation offers hearing and vocational benefits to children and adults who lose their hearing after acquiring speech and language. But such implantations in prelingually deaf children are controversial, with concerns about diagnosis in very young children, safety, and durability. Implantation of children under age 2 years is potentially associated with higher surgical and anaesthesia risks, and with more challenging preoperative and postoperative management.

STARTING POINT

Although only a small number of children implanted before age 2 have sufficient maturity and implant experience to undergo adult-type speech recognition tests, surgical series show that these children may be implanted safely and that their subsequent speech perception is at least as good as children implanted at an older age. The Nottingham, UK, group recently reported on a consecutive sample of 12 children aged under 2 years at implantation (Arch Otolaryngol Head Neck Surg 2002; 128: 11-14). S S Hehar and colleagues show satisfactory perioperative and postoperative surgical outcomes. 2 years after the implantation, mean scores on the Listening Progress Profile had increased from 1 to 42. Median scores of Categories of Auditory Performance increased from 0 to 5. There were no significant differences compared with a historical control group of deaf children implanted at ages 3-5. WHERE NEXT? Early results from parental observation of auditory behaviours show that children who receive a cochlear implant at an early age perform at least as well as those implanted later. These data, combined with more rigorous speech recognition results in older children, merit a gradual reduction in the age of implantation, although the uncertainties inherent in audiometric assessment and measurement of hearing-aid benefit in infants must be borne in mind. Cochlear implants in prelingually deafened children permit improved development of speech reception, language acquisition, and reading comprehension.

Challenges in Optimizing Oral Communication in Children With Cochlear Implants

As the number of children with cochlear implants increases, more speech and hearing professionals will be called on to take leadership roles in developing specialized intervention and educational programs. Because of their graduate-level training in speech, language, and hearing disorders, speech-language pathologists and audiologists will increasingly find themselves viewed as "local experts" on cochlear implant issues. The articles in this forum support that role by addressing topics that are critical for serving children who have cochlear implants. Although cochlear implant technology clearly has impressive potential for improving the lives of deaf children, the actualization of those improvements requires informed and concerted effort from highly skilled professionals. It is hoped that the information in this clinical forum will enable readers to expand their knowledge base and clinical skills to meet the challenges of serving children who have cochlear implants.

Communication Intervention for Children With Cochlear Implants: Two Case Studies

This article describes the intervention programs attended and progress made by 2 children who exhibited considerable differences in benefit from their cochlear implants. The children differed in many ways, including age at onset of deafness, preimplantation communications skills, age at implantation, the amount and types of intervention services received, and the rate at which they developed oral communication skills. Their intervention programs employed both analytical and synthetic auditory training and emphasized the development of speech production and language skills. These case studies help to illustrate the range of outcomes among cochlear implant recipients and the adaptability needed to design and implement individualized intervention programs.

Cantonese tone perception ability of cochlear implant children in comparison with normal-hearing children

BACKGROUND AND OBJECTIVE

Cantonese is a tone language. A change in the fundamental frequency pattern within the same phonemic segment causes a change in the lexical meaning. The present study examined the Cantonese tone perception ability of cochlear implant children in comparison with normal-hearing children. It was hypothesized that cochlear implant children follow a similar pattern of tone perception development, as do normal children.

METHOD

225 normal-hearing and 15 hearing-impaired children with cochlear implants were recruited. The high level (tone 1), high rising (tone 2) and low falling (tone 4) were the target tones examined. The three tones were arranged into tone pairs for identification. Each pair shared exactly the same segmental information but differed only in tones (e.g. /sy/ in tones 1 and 2 meaning 'book' and 'mouse', respectively). Subjects were required to point to the corresponding pictures after the live voice presentations.

RESULTS

for each tone pair, each subject was awarded a score representing the proportion of stimuli pairs that were correctly discriminated by the subject. The average scores in the normal-hearing and hearing-impaired groups were 0.92 and 0.64, respectively. The normal group had the lowest average score in tone 2/tone 4 (0.87) while the hearing-impaired group performed the worst in tone 1/tone 2 (0.53) perception between the three tone contrasts.

CONCLUSIONS

the normal-hearing group performed significantly better than the hearing-impaired group in basic Cantonese tone perception. The pattern of tone perception development of cochlear implant children did not seem to follow that of normal children. Contributing factors on the tone perception performance of the cochlear implant children were subject's age, duration of special training, and durations of wearing the hearing aid and the cochlear implant.

Cochlear and brainstem implantation

Cochlear implantation is an established habilitative and rehabilitative option for profoundly deafened individuals over 1 year of age who derive limited benefit from conventional hearing aids. Auditory performance varies among individuals and is determined primarily by age at implantation, pre-existence of speech and language skills, and the time interval between onset of deafness and implantation. Successful implant users generally demonstrate improved auditory abilities and speech production skills beyond those achieved with hearing aids. Multichannel ABIs can provide useful auditory information to patients with NF-2 who have lost integrity of auditory nerves following removal of vestibular schwannomas. The implant allows for awareness of environmental sounds and, potentially, speech recognition. Most patients undergoing implantation demonstrate improved lip-reading skills, and exceptional performers achieve understanding of open-set speech.

Binaural cochlear implants placed during the same operation

OBJECTIVE

To evaluate the binaural listening advantages for speech in quiet and in noise and to localize sound when independently programmed binaural cochlear implants are used, and to determine whether ears with different hearing ability and duration of profound deafness perform differently with cochlear implants as well as to what extent preimplant psychophysical and physiologic assessment could be predictive of performance.

STUDY DESIGN

Prospective study in which patients were prospectively selected to undergo bilateral implantation during a single surgical procedure at a tertiary referral center. All testing was performed with patients using their right, left, or both cochlear implants. Preimplant and intraoperative measures used electrical stimulation at the round window and stimulation through the cochlear implant.

RESULTS

Bilateral implantation during the same operation did not cause any postoperative problems such as severe vertigo or ataxia. At 1 year, results of speech testing in quiet demonstrated a binaural advantage for 2 of 10 subjects. Speech-in-noise testing demonstrated that two implants were beneficial for two individuals. All subjects benefited from a head shadow effect when an ear with a better signal-to-noise ratio was available. The ability to localize sound was improved with binaural implants in all subjects. Preimplant psychophysical or physiologic measures were not predictive of eventual speech perception performance.

CONCLUSION

Binaural cochlear implants can assist in the localization of sounds and have the potential in some individuals to improve speech understanding in quiet and in noise.

Analysis of narrative ability in children with cochlear implants

PURPOSE

The purposes of this study were to: 1) develop a scoring system to assess narrative ability in children; 2) evaluate the impact of auditory speech perception with a cochlear implant on narrative ability; and 3) evaluate the importance of narrative ability to reading comprehension in deaf children.

DESIGN

Narrative productions prompted from an eight-picture sequence story were elicited from 8 and 9 yr olds; 87 who had at least 4 yr of cochlear implant experience and 28 who had normal hearing. The stories were transcribed and a scoring system for narrative ability was developed based on the use of complete narrative structure, conjunctions linking semantic relations, and referents that served to identify and distinguish characters in the narrative. Narrative ability scores of cochlear implant users were examined in relation to their age, IQ, speech perception, language, and reading test scores. In addition, narrative ability scores for children with normal hearing were compared with two groups of cochlear implant users, those with above average speech perception scores and those with below average speech perception scores.

RESULTS

Within the sample of hearing-impaired children, narrative ability scores correlated significantly with speech perception, language syntax, and reading test scores. A multiple regression analysis was conducted to predict reading comprehension scores from four predictor variables (age, IQ, language syntax, and narrative ability). Results reflected the independent contribution of discourse-level language skills, as measured by the narrative ability score, as well as sentence-level language skills in predicting reading test scores. Analysis of stories obtained from 8- and 9-yr-old children with normal hearing revealed the classic pattern that included a high point, a resolution, and one or more evaluative statements. Their stories achieved cohesion from correct use of both conjunctions and referents. Deaf children who received above-average speech perception scores with a cochlear implant (i.e., scored above 48% on the Word Intelligibility by Picture Identification speech perception test) told narratives that were similar in structure and use of referents to those of age mates with normal hearing. Although their use of subordinate conjunctions was not as well developed as normal-hearing children, it was significantly above that of deaf children who received less speech perception benefit after a similar period of implant use. These below-average speech perceivers exhibited significantly poorer use of narrative structure and cohesive devices than either normal-hearing age mates or children who achieved above average speech perception with a cochlear implant.

CONCLUSIONS

Narrative ability is an important predictor of reading comprehension ability in deaf children above and beyond IQ and syntactic competence. Children who receive a cochlear implant under 5 yr of age and obtain above average speech perception benefit from the device construct narratives that are similar in structure and cohesion to those of their hearing age mates by age 8 to 9.

Use of audiovisual information in speech perception by prelingually deaf children with cochlear implants: a first report

OBJECTIVE

Although there has been a great deal of recent empirical work and new theoretical interest in audiovisual speech perception in both normal-hearing and hearing-impaired adults, relatively little is known about the development of these abilities and skills in deaf children with cochlear implants. This study examined how prelingually deafened children combine visual information available in the talker's face with auditory speech cues provided by their cochlear implants to enhance spoken language comprehension.

DESIGN

Twenty-seven hearing-impaired children who use cochlear implants identified spoken sentences presented under auditory-alone and audiovisual conditions. Five additional measures of spoken word recognition performance were used to assess auditory-alone speech perception skills. A measure of speech intelligibility was also obtained to assess the speech production abilities of these children.

RESULTS

A measure of audiovisual gain, "Ra," was computed using sentence recognition scores in auditory-alone and audiovisual conditions. Another measure of audiovisual gain, "Rv," was computed using scores in visual-alone and audiovisual conditions. The results indicated that children who were better at recognizing isolated spoken words through listening alone were also better at combining the complementary sensory information about speech articulation available under audiovisual stimulation. In addition, we found that children who received more benefit from audiovisual presentation also produced more intelligible speech, suggesting a close link between speech perception and production and a common underlying linguistic basis for audiovisual enhancement effects. Finally, an examination of the distribution of children enrolled in Oral Communication (OC) and Total Communication (TC) indicated that OC children tended to score higher on measures of audiovisual gain, spoken word recognition, and speech intelligibility.

CONCLUSIONS

The relationships observed between auditory-alone speech perception, audiovisual benefit, and speech intelligibility indicate that these abilities are not based on independent language skills, but instead reflect a common source of linguistic knowledge, used in both perception and production, that is based on the dynamic, articulatory motions of the vocal tract. The effects of communication mode demonstrate the important contribution of early sensory experience to perceptual development, specifically, language acquisition and the use of phonological processing skills. Intervention and treatment programs that aim to increase receptive and productive spoken language skills, therefore, may wish to emphasize the inherent cross-correlations that exist between auditory and visual sources of information in speech perception.

Beginning to talk at 20 months: early vocal development in a young cochlear implant recipient

Early vocal development, consonant production, and spoken vocabulary were examined in a deaf toddler whose multichannel cochlear implant was activated at 20 months. Parent-child interactions were recorded before implantation and at monthly intervals during the first year of implant use. The child's utterances were classified according to developmental levels from the Stark Assessment of Early Vocal Development. The emergence of consonant types and consonant features were documented through listener transcription. Parent reports were used to monitor oral vocabulary growth. A large increase in canonical and postcanonical utterances was observed after 5 months of implant use, and these advanced prelinguistic forms were dominant in all subsequent recording sessions. Increases in the diversity of consonant types and features suggested that auditory information was used to increase phonetic diversity. It was reported that the child understood almost 240 words and spoke approximately 90 words after one year of implant experience. The combination of cochlear implantation at a young age, family support, and regular intervention appeared to facilitate efficient early vocal development and gains in spoken vocabulary.

Language and reading acquisition in children with and without cochlear implants

These data provide a coherent view of the spoken language and reading skills of children receiving cochlear implants. The data reveal both spoken language gains and clear benefit to these children with regard to reading. Improvement in reading is consistent with predictions based on prior research demonstrating a strong association between spoken language and reading. An intervention such as a cochlear implant has a direct effect on spoken language, and this can subsequently affect reading performance. This provides some of the first experimental evidence supporting the causal relationship between spoken language and reading.

Reading Skills in Children with Multichannel Cochlear-lmplant Experience

Forty children with prelingual, profound deafness who received the Nucleus multichannel cochlear implant between the ages of 2 and 13 years participated in this study. The children had an average of 63.3 months (SD=24 months) of experience with their cochlear implants. A majority of the children used simultaneous communication and attended public-school programs at the time of testing. Reading achievement was assessed using the Paragraph Comprehension subtest of the Woodcock Reading Mastery Test-Revised, Form G (1987). This study compared the reading-achievement levels of this group of cochlear-implant users with the results of previous studies of children with profound hearing losses who did not have the benefit of cochlear implants. Results indicated that nearly one half of the children in this study were reading at or within 8 months of their grade level. The reading-grade quotient of .74 was calculated based upon the slope of the regression line for the plot of years in school and reading grade-level achieved. This finding indicates that using a cochlear implant has a positive effect on reading achievement level.