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

Communication, psychosocial, and educational outcomes of children with cochlear implants and challenges remaining for professionals and parents

This paper provides an overview and a synthesis of the findings of a large, multifaceted study investigating outcomes from paediatric cochlear implantation. The study included children implanted at several Australian implant clinics and attending a variety of early intervention and educational settings across a range of locations in eastern Australia. It investigated three major aspects of childhood cochlear implantation: (1) parental expectations of their children's implantation, (2) families' decision-making processes, and (3) the communication, social, and educational outcomes of cochlear implantation for deaf children. It employed a mixed-methods approach in which quantitative survey data were gathered from 247 parents and 151 teachers, and qualitative data from semistructured interviews with 27 parents, 15 teachers, and 11 children and adolescents with cochlear implants. The summarised findings highlight several areas where challenges remain for implant clinics, parents, and educators if children with cochlear implants are to reach their full potential personally, educationally, and socially.

Point vowel duration in children with hearing aids and cochlear implants at 4 and 5 years of age

This work investigates the developmental aspects of the duration of point vowels in children with normal hearing compared with those with hearing aids and cochlear implants at 4 and 5 years of age. Younger children produced longer vowels than older children, and children with hearing loss (HL) produced longer and more variable vowels than their normal hearing peers. In this study, children with hearing aids and cochlear implants did not perform differently from each other. Test age and HL did not interact, indicating parallel but delayed development in children with HL compared with their typically developing peers. Variability was found to be concentrated among the high vowels /u, i / but not in the low vowels /ae, a / . The broad findings of this work are consistent with previous reports and contribute a detailed description of point vowel duration not in the literature.

Pediatric cochlear implantation

PURPOSE OF REVIEW

To summarize the current state of cochlear implantation in children.

RECENT FINDINGS

Hearing loss profoundly impacts a child's ability to communicate and thereby affects educational and psychosocial development. The auditory cortex has sensitive periods during which it is maximally receptive to sound stimulus and consequent development. For this reason, there is impetus to implant children at a very young age, as a cochlear implant can provide auditory input during this critical window. Long-term follow-up of implanted children has shown that cochlear implants are able to provide substantial language, academic, and social benefit. The criteria for cochlear implantation have broadened, and promising outcomes are being seen in populations that were not previously considered for implantation. The best language acquisition outcomes are seen in recipients who were implanted at a younger age and are in an environment rich in oral communication. Bilateral implantation offers some acoustic advantages.

SUMMARY

Cochlear implants provide sound perception to deaf children and can mitigate, to varying extents, the effects of sound deprivation on auditory development. On the basis of our understanding of brain development and language outcomes, a wider population of children are now candidates for implantation than previously considered.

Article 1: Long-Term outcomes of cochlear implantation in early childhood: Sample characteristics and data collection methods

Articles contained in this monograph describe the communication performance of 112 teenagers who received multichannel cochlear implants between the ages of 2 and 5 years. Children were first tested during the elementary school years when they were 8 or 9 years of age. They also were tested as adolescents when they were between 15 and 18 years old. Characteristics of the population are described including their modes of communication and educational environments. Child, family and educational variables that will be explored in the following articles as possible predictors of successful outcomes are introduced.

Measures of digit span and verbal rehearsal speed in deaf children after more than 10 years of cochlear implantation

OBJECTIVES

Conventional assessments of outcomes in deaf children with cochlear implants (CIs) have focused primarily on endpoint or product measures of speech and language. Little attention has been devoted to understanding the basic underlying core neurocognitive factors involved in the development and processing of speech and language. In this study, we examined the development of factors related to the quality of phonological information in immediate verbal memory, including immediate memory capacity and verbal rehearsal speed, in a sample of deaf children after >10 yrs of CI use and assessed the correlations between these two process measures and a set of speech and language outcomes.

DESIGN

Of an initial sample of 180 prelingually deaf children with CIs assessed at ages 8 to 9 yrs after 3 to 7 yrs of CI use, 112 returned for testing again in adolescence after 10 more years of CI experience. In addition to completing a battery of conventional speech and language outcome measures, subjects were administered the Wechsler Intelligence Scale for Children-III Digit Span subtest to measure immediate verbal memory capacity. Sentence durations obtained from the McGarr speech intelligibility test were used as a measure of verbal rehearsal speed.

RESULTS

Relative to norms for normal-hearing children, Digit Span scores were well below average for children with CIs at both elementary and high school ages. Improvement was observed over the 8-yr period in the mean longest digit span forward score but not in the mean longest digit span backward score. Longest digit span forward scores at ages 8 to 9 yrs were significantly correlated with all speech and language outcomes in adolescence, but backward digit spans correlated significantly only with measures of higher-order language functioning over that time period. While verbal rehearsal speed increased for almost all subjects between elementary grades and high school, it was still slower than the rehearsal speed obtained from a control group of normal-hearing adolescents. Verbal rehearsal speed at ages 8 to 9 yrs was also found to be strongly correlated with speech and language outcomes and Digit Span scores in adolescence.

CONCLUSIONS

Despite improvement after 8 additional years of CI use, measures of immediate verbal memory capacity and verbal rehearsal speed, which reflect core fundamental information processing skills associated with representational efficiency and information processing capacity, continue to be delayed in children with CIs relative to NH peers. Furthermore, immediate verbal memory capacity and verbal rehearsal speed at 8 to 9 yrs of age were both found to predict speech and language outcomes in adolescence, demonstrating the important contribution of these processing measures for speech-language development in children with CIs. Understanding the relations between these core underlying processes and speech-language outcomes in children with CIs may help researchers to develop new approaches to intervention and treatment of deaf children who perform poorly with their CIs. Moreover, this knowledge could be used for early identification of deaf children who may be at high risk for poor speech and language outcomes after cochlear implantation as well as for the development of novel targeted interventions that focus selectively on these core elementary information processing variables.

Reading, writing, and phonological processing skills of adolescents with 10 or more years of cochlear implant experience

OBJECTIVES

This study had three goals: (1) to document the literacy skills of deaf adolescents who received cochlear implants (CIs) as preschoolers; (2) to examine reading growth from elementary grades to high school; (3) to assess the contribution of early literacy levels and phonological processing skills, among other factors, to literacy levels in high school.

DESIGN

A battery of reading, spelling, expository writing, and phonological processing assessments were administered to 112 high school (CI-HS) students, ages 15.5 to 18.5 yrs, who had participated in a reading assessment battery in early elementary grades (CI-E), ages 8.0 to 9.9 yrs. The CI-HS students' performance was compared with either a control group of hearing peers (N = 46) or hearing norms provided by the assessment developer.

RESULTS

Many of the CI-HS students (47 to 66%) performed within or above the average range for hearing peers on reading tests. When compared with their CI-E performance, good early readers were also good readers in high school. Importantly, the majority of CI-HS students maintained their reading levels over time compared with hearing peers, indicating that the gap in performance was, at the very least, not widening for most students. Written expression and phonological processing tasks posed a great deal of difficulty for the CI-HS students. They were poorer spellers, poorer expository writers, and displayed poorer phonological knowledge than hearing age-mates. Phonological processing skills were a critical predictor of high school literacy skills (reading, spelling, and expository writing), accounting for 39% of variance remaining after controlling for child, family, and implant characteristics.

CONCLUSIONS

Many children who receive CIs as preschoolers achieve age-appropriate literacy levels as adolescents. However, significant delays in spelling and written expression are evident compared with hearing peers. For children with CIs, the development of phonological processing skills is not just important for early reading skills, such as decoding, but is critical for later literacy success as well.

Speech production accuracy and variability in young cochlear implant recipients: comparisons with typically developing age-peers

PURPOSE

The speech production accuracy and variability scores of 6 young cochlear implant (CI) recipients with 2 years of device experience were compared with those of typically developing (TD) age-peers.

METHOD

Words from the First Words Speech Test (FWST; Ertmer, 1999) were imitated 3 times to assess the accuracy and variability of initial consonants, vowels, and words. The initial consonants in the 4 sets of the FWST followed a typical order of development.

RESULTS

The TD group produced targets with high accuracy and low variability. Their scores across FWST sets reflected the expected order of development. The CI group produced most targets less accurately and with more variability than the TD children. Relatively high accuracy for the consonants of Sets 1 and 2 indicated that these phonemes were acquired early and in a typical developmental order. A trend toward greater accuracy for Set 4 as compared with Set 3 suggested that later-emerging consonants were not acquired in the expected order. Variability was greatest for later-emerging initial consonants and whole words.

DISCUSSION

Although considerable speech production proficiency was evident, age-level performance was not attained after 2 years of CI experience. Factors that might influence the order of consonant acquisition are discussed.

Psychosocial adjustment in adolescents who have used cochlear implants since preschool

OBJECTIVES

This study examined psychosocial characteristics of students who had used a cochlear implant (CI) since preschool and were evaluated when they were in elementary grades and again in high school. The study had four goals: (1) to determine the extent to which psychosocial skills documented in elementary grades were maintained into high school; (2) to assess the extent to which long-term CI users identified with the Deaf community or the hearing world or both; (3) to examine the association between group identification and the student's sense of self-esteem, preferred communication mode, and spoken language skills; and (4) to describe the extracurricular world of the teenagers who were mainstreamed with hearing age-mates for most of their academic experience.

DESIGN

As part of a larger study, 112 CI students (aged 15.0 to 18.6 yrs) or their parents completed questionnaires describing their social skills, and a subsample of 107 CI students completed group identification and self-esteem questionnaires. Results were compared with either a control group of hearing teenagers (N = 46) or age-appropriate hearing norms provided by the assessment developer.

RESULTS

Average psychosocial ratings from both parents and students at both elementary grades and high school indicated a positive self-image throughout the school years. Seventy percent of the adolescents expressed either strong identification with the hearing community (32%) or mixed identification with both deaf and hearing communities (38%). Almost all CI students (95%) were mainstreamed for more than half of the day, and the majority of students (85%) were in the appropriate grade for their age. Virtually all CI students (98%) reported having hearing friends, and a majority reported having deaf friends. More than 75% of CI students reported that they used primarily spoken language to communicate and that good spoken language skills enabled them to participate more fully in all aspects of their lives. Identification with the hearing world was not associated with personal or social adjustment problems but was associated with better speech perception and English language skill. Ninety-four percent were active participants in high school activities and sports, and 50% held part-time jobs (a rate similar to that documented for hearing teens).

CONCLUSIONS

The majority of these early-implanted adolescents reported strong social skills, high self-esteem, and at least mixed identification with the hearing world. However, these results must be viewed in light of possible sources of sample selection bias and may not represent the psychosocial characteristics of the entire population of children receiving CIs.

Single word and sentence intelligibility in children with cochlear implants

This study examined the intelligibility of speech produced by 17 children (aged 4-11 years) with cochlear implants. Stimulus items included sentences from the Beginners' Intelligibility Test (BIT) and words from the Children Speech Intelligibility Measure (CSIM). Naïve listeners responded by writing sentences heard or with two types of responses to the word recordings; open transcription (CSIM-T) and closed set multiple choice (CSIM-MC). Percentage of items understood, averaged across three naïve judges, were compared across the three measures. Additionally, scores were examined for any relationships with chronological age, age of implantation, and amount of implant experience. Strong positive correlations were observed among all three intelligibility tasks. Scores on all three tasks were found to be significantly different from each other. A significant correlation was obtained between intelligibility and amount of implant experience, but not with chronological age or age of implantation. Results suggest that judging the intelligibility of speech produced by children with cochlear implants using both single word and sentence levels would provide a better overall estimate of their intelligibility. The results also emphasize the vital role of auditory input in the development of intelligible speech.

Speech production intelligibility of early implanted pediatric cochlear implant users

OBJECTIVES

To investigate the influence of age, and age-at-implantation, on speech production intelligibility in prelingually deaf pediatric cochlear implant recipients.

METHODS

Forty prelingually, profoundly deaf children who received cochlear implants between 8 and 40 months of age. Their age at testing ranged between 2.5 and 18 years. Children were recorded repeating the 10 sentences in the Beginner's Intelligibility Test. These recordings were played back to normal-hearing listeners who were unfamiliar with deaf speech and who were instructed to write down what they heard. They also rated each subject for the intelligibility of their speech production on a 5-point rating-scale. The main outcome measures were the percentage of target words correctly transcribed, and the intelligibility ratings, in both cases averaged across 3 normal-hearing listeners.

RESULTS

The data showed a strong effect of age at testing, with older children being more intelligible. This effect was particularly pronounced for children implanted in the first 24 months of life, all of whom had speech production intelligibility scores of 80% or higher when they were tested at age 5.5 years or older. This was true for only 5 out of 9 children implanted at age 25-36 months.

CONCLUSIONS

Profoundly deaf children who receive cochlear implants in the first 2 years of life produce highly intelligible speech before the age of 6. This is also true for most, but not all children implanted in their third year.

Reading and spelling abilities of deaf adolescents with cochlear implants and hearing AIDS

A total of 86 deaf children aged between 12 and 16 years were recruited from schools for the deaf, specialist units attached to a school, and mainstream schools. Approximately one-third used hearing aids, one-third had received a cochlear implant before 42 months, and one-third had been implanted later. The 3 subgroups were matched for age and nonverbal IQ, and all had an unaided hearing loss of at least 85 dB. Assessments revealed mean reading ages that were several years below chronological age for all 3 groups. However, participants in the hearing aid group performed best. Reading levels were not predicted by age of diagnosis or degree of hearing loss, but there was a relationship between reading level and presence of phonetic errors in spelling. There were also differences in educational setting, with the great majority of children in the hearing aid group in a school for the deaf and relatively more of the children with cochlear implants being educated in a unit or mainstream setting.

Assessing speech intelligibility in children with hearing loss: toward revitalizing a valuable clinical tool

BACKGROUND

Newborn hearing screening, early intervention programs, and advancements in cochlear implant and hearing aid technology have greatly increased opportunities for children with hearing loss to become intelligible talkers. Optimizing speech intelligibility requires that progress be monitored closely. Although direct assessment of intelligibility has been a cumbersome undertaking, advancements in digital recording technology and expanded strategies for recruiting listener-judges can make this tool much more practical in contemporary school and clinical settings.

PURPOSE

The main purposes of this tutorial are to present a rationale for assessing children's connected speech intelligibility, review important uses for intelligibility scores, and describe time-efficient ways to estimate how well children's connected speech can be understood. This information is offered to encourage routine assessment of connected speech intelligibility in preschool and school-age children with hearing loss.

Choosing for the child with cochlear implants: a note of precaution

Recent contributions to discussions on paediatric cochlear implantation in Norway indicate two mutually exclusive doctrines prescribing the best course of post-operative support for a child with cochlear implants; bilingually with sign language and spoken language simultaneously or primarily monolingually with speech only. This conflict constitutes an ethical problem for parents responsible for choosing between one of the two alternatives. This article puts forth the precautionary principle as a possible solution to this problem. Although scientific uncertainty exists in the case of both doctrines, there exists a scenario of possible irreversible harm to some of the children habilitated monolingually. An application of the precautionary principle may hence suggest that it is rational to agree on the bilingual approach, at least for the time-being.

Spoken language development in children following cochlear implantation

CONTEXT

Cochlear implantation is a surgical alternative to traditional amplification (hearing aids) that can facilitate spoken language development in young children with severe to profound sensorineural hearing loss (SNHL).

OBJECTIVE

To prospectively assess spoken language acquisition following cochlear implantation in young children.

DESIGN, SETTING, AND PARTICIPANTS

Prospective, longitudinal, and multidimensional assessment of spoken language development over a 3-year period in children who underwent cochlear implantation before 5 years of age (n = 188) from 6 US centers and hearing children of similar ages (n = 97) from 2 preschools recruited between November 2002 and December 2004. Follow-up completed between November 2005 and May 2008.

MAIN OUTCOME MEASURES

Performance on measures of spoken language comprehension and expression (Reynell Developmental Language Scales).

RESULTS

Children undergoing cochlear implantation showed greater improvement in spoken language performance (10.4; 95% confidence interval [CI], 9.6-11.2 points per year in comprehension; 8.4; 95% CI, 7.8-9.0 in expression) than would be predicted by their preimplantation baseline scores (5.4; 95% CI, 4.1-6.7, comprehension; 5.8; 95% CI, 4.6-7.0, expression), although mean scores were not restored to age-appropriate levels after 3 years. Younger age at cochlear implantation was associated with significantly steeper rate increases in comprehension (1.1; 95% CI, 0.5-1.7 points per year younger) and expression (1.0; 95% CI, 0.6-1.5 points per year younger). Similarly, each 1-year shorter history of hearing deficit was associated with steeper rate increases in comprehension (0.8; 95% CI, 0.2-1.2 points per year shorter) and expression (0.6; 95% CI, 0.2-1.0 points per year shorter). In multivariable analyses, greater residual hearing prior to cochlear implantation, higher ratings of parent-child interactions, and higher socioeconomic status were associated with greater rates of improvement in comprehension and expression.

CONCLUSION

The use of cochlear implants in young children was associated with better spoken language learning than would be predicted from their preimplantation scores.

Articulation skills in Turkish speaking children with cochlear implant

OBJECTIVE

The benefits of using cochlear implant (CI) on speech perception and production have been documented. The aim of this study is to investigate the effect of age of cochlear implantation performed and length of auditory experience with CI on the development of articulation skills in prelingual children with CI.

METHODS

For this purpose, 14 children with CI were administered through the standardized articulation test named AAT (Ankara Articulation Test). In order to evaluate the development of articulation skills, AAT was applied to each child with CI at the first and the fourth years of CI. The test group was selected among those congenitally hearing impaired children who had used hearing aids bilaterally before the age of one and a half, and received intervention after fitting hearing aids. The test group was divided into two subgroups: Group 1 consisted of the children implanted at and below the age of 3 and Group 2 consisted of the children implanted after the age of 3. Evaluations of articulation skills between groups and within groups were performed in the first and fourth years of implantation. In the study, nonparametric statistics have been used to compare the test scores. Mann-Whitney U-test and Wilcoxon test have been used in the comparisons made between groups and within groups, respectively.

RESULTS

While there has not been observed any statistically significant difference between the first year articulation skills of children with CI at and below the age of three and children with CI above the age of 3, for the fourth year this difference has been found to be statistically significant.

CONCLUSIONS

The results demonstrate the importance of the early application of CI and length of auditory experience with CI in the development of articulation skills.

Vocal singing by prelingually-deafened children with cochlear implants

The coarse pitch information in cochlear implants might hinder the development of singing in prelingually-deafened pediatric users. In the present study, seven prelingually-deafened children with cochlear implants (5.4-12.3 years old) sang one song that was the most familiar to him or her. The control group consisted of 14 normal-hearing children (4.1-8.0 years old). The fundamental frequencies (F0) of each note in the recorded songs were extracted. The following five metrics were computed based on the reference music scores: (1) F0 contour direction of the adjacent notes, (2) F0 compression ratio of the entire song, (3) mean deviation of the normalized F0 across the notes, (4) mean deviation of the pitch intervals, and (5) standard deviation of the note duration differences. Children with cochlear implants showed significantly poorer performance in the pitch-based assessments than the normal-hearing children. No significant differences were seen between the two groups in the rhythm-based measure. Prelingually-deafened children with cochlear implants have significant deficits in singing due to their inability to manipulate pitch in the correct directions and to produce accurate pitch height. Future studies with a large sample size are warranted in order to account for the large variability in singing performance.

Is age at implant the only factor that counts? The influence of working memory on lexical and grammatical development in children with cochlear implants

In this study, we explored the influence of time factors (age at implant, time with cochlear implant and age), complex working memory and phonological short-term memory on lexical and grammatical development in congenitally deaf children with cochlear implants. Fifteen children (aged 5 years 4 months to 11 years 5 months) were examined with the use of several linguistic and cognitive measures after a minimum of 18 months of implant use. Phonological short-term memory was assessed with non-word repetition, where the percentage of correctly repeated consonants and vowels was counted. For the assessment of lexical acquisition. a novel word learning task was administered. Receptive and expressive grammar was tested. Our results corroborate earlier findings on the influence of phonological short-term memory on novel word learning. The percentage of vowels correctly produced in non-word repetition was more important in this group than age at implant, not only for novel word learning. but also for receptive and expressive grammar.

Development of speech intelligibility and narrative abilities and their interrelationship three and five years after paediatric cochlear implantation

This study sought to determine the level of speech intelligibility, narrative abilities, and their interrelationship in 18 Finnish children implanted at the average age of three years, four months. Additionally, background factors associated with speech intelligibility and storytelling ability were examined. Speech intelligibility was examined by means of an item identification task with five listeners per child. Three and five years after activation of the implant, the children reached average intelligibility scores of 53% and 81%, respectively. The story generation abilities of the implanted children exceeded their hearing age by one year, on average. This was found after comparing their results with those of normally-hearing two- to six-year-olds (N = 49). According to multiple regression analysis, comorbidity (number of additional needs), chronological age, and/or age at activation usually explained from 46% to 70% of the variation in speech intelligibility and narrative abilities. After controlling for age, communication mode, and number of additional needs, speech intelligibility and ability to narrate were statistically significantly associated with each other three years after activation, but not anymore five years after activation.

Reading abilities after cochlear implantation: the effect of age at implantation on outcomes at 5 and 7 years after implantation

OBJECTIVES

The reading skills of deaf children have typically been delayed and this delay has been found to increase with age. This study explored the reading ability of a large group of children who had received cochlear implants 7 years earlier and investigated the relationship between reading ability and age at implantation.

METHODS

The reading ages of 105 children, with age at implantation less than 7 years and onset of deafness below the age of three, were assessed 5 and 7 years after implantation using the Edinburgh reading test. Net reading age was calculated by using the difference between chronological age and reading age. Non-verbal intelligence was measured for a subset of 71 children, using Raven's coloured progressive matrices. Further investigation of this subset looked at the association of nonverbal intelligence, age at implantation and reading ability.

RESULTS

There was a strong negative correlation at both 5 and 7 years after implant between net reading score and age at implantation. In the subset of 71 children who had an IQ score within normal range, those implanted at or before 42 months had age-appropriate reading both 5 and 7 years post-implant. This was not the case for children implanted after 42 months. Reading progress at the two post-implant assessment intervals were found to be highly related.

CONCLUSIONS

Age at implantation was a significant factor in the development of reading skills in this group. In children implanted below the age of 42 months, reading progress was in line with chronological age, which has not been the case previously with profoundly deaf children. With earlier implantation more common in present groups, and improved technology, there is every reason to be optimistic about the influence of cochlear implantation on the development of reading skills in deaf children.

Fricatives, affricates, and vowels in Croatian children with cochlear implants

The aim of the research was to analyse the speech of children with cochlear implants over approximately a 46-month period, and compare it with the speech of hearing controls. It focused on three categories of sounds in Croatian: vowels (F1 and F2 of /i/, /e/, /a/, /o/ and /u/), fricatives /s/ and /integral/ (spectral differences expressed in terms of center of gravity), and affricates /ts/ and /t integral/ (accuracy, total duration, and pattern of stop-fricative components). One group of subjects were 10 implanted children who had been profoundly deaf before implantation. There were four recordings per child. Group two children were hearing controls matched for age and sex. The results show that the implanted children are closest to unimpaired children in terms of their formant-defined vowel space. Their fricatives exhibit poor distinction in terms of the noise spectrum, and the affricates are the most difficult to produce.

Long-term trajectories of the development of speech sound production in pediatric cochlear implant recipients

PURPOSE

This study characterized the development of speech sound production in prelingually deaf children with a minimum of 8 years of cochlear implant (CI) experience.

METHOD

Twenty-seven pediatric CI recipients' spontaneous speech samples from annual evaluation sessions were phonemically transcribed. Accuracy for these speech samples was evaluated in piecewise regression models.

RESULTS

As a group, pediatric CI recipients showed steady improvement in speech sound production following implantation, but the improvement rate declined after 6 years of device experience. Piecewise regression models indicated that the slope estimating the participants' improvement rate was statistically greater than 0 during the first 6 years postimplantation, but not after 6 years. The group of pediatric CI recipients' accuracy of speech sound production after 4 years of device experience reasonably predicts their speech sound production after 5-10 years of device experience.

CONCLUSIONS

The development of speech sound production in prelingually deaf children stabilizes after 6 years of device experience, and typically approaches a plateau by 8 years of device use. Early growth in speech before 4 years of device experience did not predict later rates of growth or levels of achievement. However, good predictions could be made after 4 years of device use.

Cochlear implantation in deaf children with associated disabilities: challenges and outcomes

The issue of cochlear implantation in deaf children with associated disabilities is an emerging subject. Currently, there is no consensus on whether to implant children with multiple impairments; moreover, it may be difficult to evaluate these children with standard tests pre- or post-implantation. In addition, these children often have poor speech perception and language skills, making assessment more difficult. Despite these factors, these children often receive important benefits in daily life, with an overall improvement in quality of life. In the present study, post-implant outcomes of 23 profoundly deaf children with neuropsychiatric disorders were analysed, using objective measures of speech perception, and a questionnaire administered to the parents, aimed at evaluating the benefits in daily life after implantation. The results were quite variable, but overall positive, in terms of speech perception, communication abilities, and improvement in quality of life. The findings add an additional piece of evidence to support the effectiveness of cochlear implantation in these special cases.

Efficacy of the discreteness of voicing category (DOVC) measure for characterizing voicing errors in children with cochlear implants: a report

PURPOSE

This investigation explored the utility of an acoustic measure, called the discreteness of voicing category (DOVC), in identifying voicing errors in stop consonants produced by children with cochlear implants. Another objective was to examine the perceptual relevance of the DOVC measure and 2 commonly used voice onset time (VOT)-based measures, namely, mean VOT and DeltaVOT (e.g., VOT /t/-VOT /d/).

METHOD

Phonetic transcription and acoustic analyses were carried out on syllable-initial /t / and /d/ produced by 10 children with cochlear implants. The DOVC was calculated as the difference between the shortest VOT value of a voiceless stop and the longest VOT value of a voiced stop across several productions of each.

RESULTS

Phonetic transcription revealed that 4 of the 10 talkers demonstrated atypical voicing distinctions. Acoustic analyses indicated that the DOVC measure identified these same 4 talkers as producing atypical values, whereas mean VOT and DeltaVOT identified a different set of talkers as demonstrating values outside the normal ranges.

CONCLUSION

Preliminary findings suggest that the DOVC measure corresponded with perceptual data better than the other acoustic measures examined in the present study. Data indicate that the DOVC measure may provide perceptually relevant information concerning the production of voicing distinctions.

Expected test scores for preschoolers with a cochlear implant who use spoken language

PURPOSE

The major purpose of this study was to provide information about expected spoken language skills of preschool-age children who are deaf and who use a cochlear implant. A goal was to provide "benchmarks" against which those skills could be compared, for a given age at implantation. We also examined whether parent-completed checklists of children's language were correlated with results of standardized language tests and whether scores increased linearly with decreasing age of implantation and increasing duration of cochlear implant use.

METHOD

Participants were a nationwide sample of 76 children who were deaf and orally educated and who received an implant by 38 months of age. Formal language tests were administered at age 4.5 years. The MacArthur-Bates Communicative Development Inventories (CDI) instrument was completed by parents when children were ages 3.5 and 4.5 years.

RESULTS

Based on regression analyses, expected scores for each age at implant were provided for 2 commonly administered language tests at 4.5 years of age and CDI subscale scores at 3.5 and 4.5 years. Concurrent test scores were significantly correlated on all measures. A linear relation was found that predicted increasing test scores with younger ages at implantation for all scales administered.

CONCLUSIONS

While the expected scores reported here should not be considered as normative data, they are benchmarks that may be useful for evaluating spoken language progress of children with cochlear implants who are enrolled in spoken language-based programs.

Early listening and speaking skills predict later reading proficiency in pediatric cochlear implant users

OBJECTIVES

Previous studies have reported that children who use cochlear implants (CIs) tend to achieve higher reading levels than their peers with profound hearing loss who use hearing aids. The purpose of this study was to investigate the influences of auditory information provided by the CI on the later reading skills of children born with profound deafness. The hypothesis was that there would be a positive and predictive relationship between earlier speech perception, production, and subsequent reading comprehension.

DESIGN

The speech perception and production skills at the vowel, consonant, phoneme, and word level of 72 children with prelingual, profound hearing loss were assessed after 48 mos of CI use. The children's reading skills were subsequently assessed using word and passage comprehension measures after an average of 89.5 mos of CI use. A regression analysis determined the amount of variance in reading that could be explained by the variables of perception, production, and socioeconomic status.

RESULTS

Regression analysis revealed that it was possible to explain 59% of the variance of later reading skills by assessing the early speech perception and production performance. The results indicated that early speech perception and production skills of children with profound hearing loss who receive CIs predict future reading achievement skills. Furthermore, the study implies that better early speech perception and production skills result in higher reading achievement. It is speculated that the early access to sound helps to build better phonological processing skills, which is one of the likely contributors to eventual reading success.

Production of consonants by prelinguistically deaf children with cochlear implants

Consonant production following the sensory restoration of audition was investigated in 22 prelinguistically deaf French children who received cochlear implants. Spontaneous speech productions were recorded at 6, 12, and 18 months post-surgery and consonant inventories were derived from both glossable and non-glossable phones using two acquisition criteria. The results showed that children initiated appropriate production of consonants after six months of implant use. Stops and labials were the most frequently produced speech sounds, whereas glides and palatals were still infrequent after 18 months. Speech accuracy also improved throughout the study. Consonant visibility appeared to influence the order of acquisition in the first months following the implantation and, as experience with auditory information increased, patterns of development tended to resemble those seen in children with normal hearing. Finally, a signed mode of communication and oral rehabilitation programs prior to implantation were better outcome predictors than age at implantation.

Receptive Language and Speech Production in Children with Auditory Neuropathy/Dyssynchrony Type Hearing Loss

OBJECTIVE

The purpose of this study was to characterize the receptive language and speech production abilities of school-aged children with auditory neuropathy/dyssynchrony (AN/AD) and to compare those abilities to children with sensorineural (SN) hearing loss of similar age and degree of hearing loss.

DESIGN

Standardized speech and language tests were carried out on 12 AN/AD children, aged between 57 and 167 mo. Each of these subjects was a full-time hearing aid user or had been just before testing. Receptive language skills were assessed using the Peabody Picture Vocabulary Test (PPVT) and speech production ability was measured using the Diagnostic Evaluation of Articulation and Phonology (DEAP) and a Speech Intelligibility Rating Scale. Data from a matched cohort of children with sensorineural hearing loss were also obtained.

RESULTS

Receptive vocabulary and speech production were delayed (to varying degrees) in each of the AN/AD subjects (relative to normally hearing children). The group PPVT Language Quotient score was 0.65 +/- 0.19 and the average number of pronunciation errors was 11 +/- 8.4% higher than expected for age. Results for the AN/AD group were however similar to those obtained for a matched group of children with sensorineural hearing loss on both language and speech production measures.

CONCLUSIONS

The findings of this study indicate that while AN/AD type hearing loss can pose a significant developmental risk, at least some children fit with conventional amplification can develop reasonable speech and language abilities.

Ten-Year Follow-Up of a Consecutive Series of Children With Multichannel Cochlear Implants

OBJECTIVES

To assess a group of children who consecutively received implants more than 10 years after implantation with regard to speech perception, speech intelligibility, receptive language level, and academic/occupational status.

STUDY DESIGN

A prospective longitudinal study.

SETTING

Pediatric referral center for cochlear implantation.

PATIENTS

Eighty-two prelingually deafened children received the Nucleus multichannel cochlear implant.

INTERVENTIONS

Cochlear implantation with Cochlear Nucleus CI22 implant.

MAIN OUTCOME MEASURES

The main outcome measures were open-set Phonetically Balanced Kindergarten word test, discrimination of sentences in noise, connective discourse tracking (CDT) using voice and telephone, speech intelligibility rating (SIR), vocabulary knowledge measured using the Peabody Picture Vocabulary Test (Revised), academic performance on French language, foreign language, and mathematics, and academic/occupational status.

RESULTS

After 10 years of implant experience, 79 children (96%) reported that they always wear the device; 79% (65 of 82 children) could use the telephone. The mean scores were 72% for the Phonetically Balanced Kindergarten word test, 44% for word recognition in noise, 55.3 words per minute for the CDT, and 33 words per minute for the CDT via telephone. Thirty-three children (40%) developed speech intelligible to the average listener (SIR 5), and 22 (27%) developed speech intelligible to a listener with little experience of deaf person's speech (SIR 4). The measures of vocabulary showed that most (76%) of children who received implants scored below the median value of their normally hearing peers. The age at implantation was the most important factor that may influence the postimplant outcomes. Regarding educational/vocational status, 6 subjects attend universities, 3 already have a professional activity, 14 are currently at high school level, 32 are at junior high school level, 6 additional children are enrolled in a special unit for children with disability, and 3 children are still attending elementary schools. Seventeen are in further noncompulsory education studying a range of subjects at vocational level.

CONCLUSION

This long-term report shows that many profoundly hearing-impaired children using cochlear implants can develop functional levels of speech perception and production, attain age-appropriate oral language, develop competency level in a language other than their primary language, and achieve satisfactory academic performance.

Speech development in children after cochlear implantation

We evaluated the long-term speech intelligibility of young deaf children after cochlear implantation (CI). A prospective study on 47 consecutively implanted deaf children with up to 5 years cochlear implant use was performed. The study was conducted at a pediatric tertiary referral center for CI. All children in the study were deaf prelingually. They each receive implant before the program of auditory verbal therapy. A speech intelligibility rating scale evaluated the spontaneous speech of each child before and at frequent interval for 5 years after implantation. After cochlear implantation, the difference between the speech intelligibility, rating increased significantly each year for 3 years (P < 0.05). For the first year, the average rating remained "prerecognizable words" or "unintelligible speech". After 2 year of implantation the children had intelligible speech if someone concentrates and lip-reads (category 3). At the 4- and 5-year interval, 71.5 and 78% of children had intelligible speech to all listeners (category 5), respectively. So, 5 years after rehabilitation mode and median of speech intelligibility rating was five. Congenital and prelingually deaf children gradually develop intelligible speech that does not plateau 5 years after implantation.

Tone production of Mandarin Chinese speaking children with cochlear implants

OBJECTIVE

The purpose of the present study was to investigate tone production performance of native Mandarin Chinese speaking children with cochlear implants and to evaluate the effects of age at implantation and duration of implant use on tone production in those children.

METHODS

Fourteen prelingually deaf children who had received cochlear implantation and 14 age-matched normal-hearing children participated in the study. Both groups were of native Mandarin Chinese speaking children. One hundred and sixty tone tokens were recorded from each of the children. The total of 4480 tokens (160x28) were then used in the tone perception tests in which seven normal-hearing native Mandarin Chinese speaking adults participated.

RESULTS

The tone production of the cochlear implant children showed tremendous individual variability. The group mean performance was 48.4% correct, statistically significantly lower than the group mean performance of 78.0% correct in the normal-hearing controls. The tone confusion matrix analysis revealed that the production of Mandarin tone 2 (the rising tone) was most severely impaired in the cochlear implant children, followed by tone 3 (the low and dipping tone) and tone 4 (the falling tone). The most frequently perceived tone irrespective of the target tone was tone 1 (the high level tone). The tone production performance was negatively correlated with the age at implantation and positively correlated with the duration of implant use.

CONCLUSIONS

There is a remarkable deficit in tone production in a majority of native tone language speaking, prelingually deaf children who have received cochlear implants. While an increased duration of implant use might facilitate tone production, the age at implantation appears to have a negative effect on tone production in cochlear implant children. Therefore, early implantation might be beneficial to tone production in prelingually deaf children whose native language is a tone language.

Binaural processing in children using bilateral cochlear implants

Binaural auditory brainstem processing was examined using evoked potential measures in 40 children who were implanted early and received a second implant simultaneously or after long or short periods of unilateral implant use. Wave latencies were shorter when evoked by the experienced versus naïve implanted ear at initial bilateral activation. Binaural difference waves were detected in most children in response to apical but not basal electrode stimulation and were prolonged in latency in children implanted after long or short delays between implants. Timing differences between the implanted ears in children receiving sequential but not simultaneous bilateral implants reflect a relative immaturity of pathways innervating the second ear and results in abnormal timing of binaural processing at this initial implant stage.

Effects of auditory feedback deprivation length on the vowel /epsilon/ produced by pediatric cochlear-implant users

Effects of auditory deprivation on speech production by ten cochlear-implanted children were investigated by turning off the implant for durations ranging from 0.3 to 5.0 s and measuring the formant frequencies (F1 and F2) of the vowel /epsilon/. In five of the ten talkers, F1 and/or F2 shifted when auditory feedback was eliminated. Without feedback, F2 frequency lowered consistently, suggesting vowel centralization. Phonetic transcription indicated that some of these acoustic changes led to perceptible shifts in phonetic quality. The results provide evidence that brief periods of auditory deprivation can produce perceptible changes in vowels produced by some cochlear-implanted children.

Effects of elicitation task variables on speech production by children with cochlear implants

Given the interest in comparing speech production development in children with normal hearing and hearing impairment, it is important to evaluate how variables within speech elicitation tasks can differentially affect the acoustics of speech production for these groups. In a first experiment, children (6-14 years old) with cochlear implants produced a set of monosyllabic words either in isolation or while simultaneously signing the word. Acoustical analyses indicated no change in word duration, voice onset time, intensity, or fundamental frequency between isolated and simultaneous signing conditions. In a second experiment, the same children verbally repeated words that were signed by a video model. The model either signed with inflection or without. Words repeated after inflected models were higher in fundamental frequency and intensity and were more intelligible. In addition, children with poorer speech perception skills sometimes produced the monosyllables as 2 syllables, but this only occurred for words that had multiple sign movements. The results have implications for the comparison of speech development between children with normal hearing and those with hearing impairment.

Educational performance of pediatric cochlear implant recipients in mainstream classes

OBJECTIVES

The present study documents the school performance of 20 pediatric cochlear implant recipients who attended mainstream classes and compares their educational performance with their normally hearing peers.

METHODOLOGY

All 20 school-aged children who underwent cochlear implantation at the Universiti Kebangsaan Malaysia cochlear implant programme participated in this study. Three measures were employed to assess the school performance. First, using the SIFTER teacher-rating scale, the second measure was the child's examination results, and the third was the child's standing compared to his/her peers in language subject, mathematics, and the overall academic performance during the end of semester examinations.

RESULTS

The SIFTER rating scale indicated that only 11.8% of the children were identified as not educationally at risk, 17.6% passed four of the SIFTER subtests, whereas the other 71.6% failed in at least two of the subtests on SIFTER. The highest pass rate was obtained in behavior subtest (76.5%), followed by classroom participation (70.6%), attention (58.8%), academic (47.1%), and communication (11.8%). On the educational performance, the cochlear implant recipients performed significantly better in mathematics (mean scores 62.67%; S.D. 22.24) than in language (mean scores 49.96%, S.D. 25.88) (p<0.01). In the overall examination performance, 25.00% had above average performance (>75th percentile), 18.75% had average performance (25-75th percentile), and another 56.25% performed at below average (<25th percentile).

CONCLUSION

Children with cochlear implant were rated poorly in the SIFTER communication subtest. It is possible that language deficit presents an educational challenge in these children. The educational performance of children with cochlear implants in mainstream classes varies. Although 43.75% of them thrive well in a full-time mainstream setting, a significant percentage of them (56.25%) performed at below the average level. These findings reemphasize that although a cochlear implant has successfully provided deaf children with a good hearing potential, the majority of its recipients still require additional educational supports in order to function well in the mainstream educational setting.

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 child's auditory, speech and language development following cochlear implantation. Intrinsic characteristics of the implanted child, including gender, family socio-economic 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 orally-educated children tested by different laboratories were compared using multiple regression analysis to illustrate interactions among predictor variables. Four predictor variables accounted for a similar proportion of variance (23% and 24%) in receptive vocabulary (PPVT) 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 variance accounted for to almost 40%, but also increased the effect of implant age as a predictor variable. A different result was observed in the other sample, were the added predictor variable was nonverbal IQ, where the estimated contribution of implant age was reduced. The current analysis suggests that future analyses minimally control for independent contributions of implant age, nonverbal IQ, and pre-implant aided thresholds when examining expected outcomes. Children in both samples who received a cochlear implant sometime between their first and second birthday achieved age-appropriate oral receptive vocabulary levels during preschool.

An exploration of demographic bias in a questionnaire survey of hearing-impaired children: implications for comparisons of children with and without cochlear implants

OBJECTIVES

Responders to questionnaire surveys, who are self-selecting, are generally accepted to be unrepresentative of the total available population, at least in demographic terms. Since demographic and other variables are known to be predictive of outcome, it is important to understand the extent of that unrepresentativeness when using survey data to report comparisons of outcome. This paper aims (i) to evaluate the extent to which a sample of hearing-impaired children surveyed by postal questionnaire was representative of the population of hearing-impaired children in the United Kingdom (UK), and (ii) to identify demographic differences between children with and without cochlear implants.

METHODS

Data from a previously reported total ascertainment of hearing-impaired children in the UK which identified 17,160 with permanent bilateral hearing impairment >40 dB HL were compared with data collected by postal questionnaire for a sample of 3224 children, including 527 with cochlear implants.

RESULTS

The sampled children were similar to the ascertained population in gender, age at onset of hearing impairment, and number of additional disabilities, but came from more recent birth cohorts and from more affluent families. Compared with profoundly impaired non-implanted children, implanted children had greater degrees of hearing loss, fewer additional disabilities, a later age of onset, were younger, came from more affluent families, were more likely to use spoken language at home, and to be taught using spoken language only.

CONCLUSIONS

Comparisons of outcomes and generalisation of results require adjustment for relevant variables to avoid confounding estimates of the effectiveness of interventions including cochlear implantation.

Phonological abilities of hearing-impaired Cantonese-speaking children with cochlear implants or hearing AIDS

PURPOSE

This article examined the phonological skills of 2 groups of Cantonese-speaking children with prelingual, profound bilateral hearing loss. The phonological abilities of 7 children fitted with hearing aids were compared with the abilities of 7 children who wore cochlear implants.

METHOD

Participants in each group ranged in age from 5;1 to 6;4 years. The participants were asked to name 57 pictures and retell 2 stories. Phonological abilities were described in terms of the participants' phonological units and the phonological processes used. The participants' perception of single words was assessed using a Cantonese phonology test that includes tonal, segmental, and semantic distracters.

RESULTS

All except 1 participant had incomplete phonetic repertories. All participants showed complete vowel and tone inventories. The study group used both developmental rules and nondevelopmental phonological rules. For perception of single words, participants chose the target word most often. The cochlear implant users had a significantly higher percentage correct score for consonant production than hearing aid users.

CONCLUSIONS

The prediction that Cantonese children wearing cochlear implants would have better phonological skills than children having hearing aids with a similar degree of hearing loss was confirmed. Cochlear implant usage appeared to promote consonant feature production development to a greater degree than did the use of a hearing aid.

Cochlear implantation in children: implications for the primary care provider

PURPOSE

To define hearing loss (HL), discuss the impact of HL on child development, and review the literature on cochlear implantation in children. The criteria for and the benefits and limitations of cochlear implantation in children, as well as the implications for the primary care provider with regard to children who have cochlear implants, are presented.

DATA SOURCES

Review of published literature on the topic.

CONCLUSIONS

A child's future development depends greatly on speech and language skills. Any type of HL can impact and may even hinder speech and language acquisition. It is therefore crucial to enforce early identification of HL. For severe to profoundly hearing-impaired children, cochlear implantation serves as an avenue for hearing and language development.

IMPLICATIONS FOR PRACTICE

Nurse practitioners ought to be up to date with criteria for and the benefits and risks of cochlear implantation. Health-related issues, such as vaccination, otitis media, and meningitis, must be assessed for and managed promptly.

Development of visual attention skills in prelingually deaf children who use cochlear implants

OBJECTIVE

To determine the effects of length of cochlear implant use and other demographic factors on the development of sustained visual attention in prelingually deaf children and to examine the relations between performance on a test of sustained visual attention and audiological outcome measures in this population.

DESIGN

A retrospective analysis of data collected before cochlear implantation and over several years after implantation. Two groups of prelingually deaf children, one >6 years old (N = 41) and one <6 years old (N = 47) at testing, were given an age-appropriate Continuous Performance Task (CPT). In both groups, children monitored visually presented numbers for several minutes and responded whenever a designated number appeared. Hit rate, false alarm rate, and signal detection parameters were dependent measures of sustained visual attention. We tested for effects of a number of patient variables on CPT performance. Multiple regression analyses were conducted to determine if CPT scores were related to performance on several audiological outcome measures.

RESULTS

In both groups of children, mean CPT performance was low compared with published norms for normal-hearing children, and performance improved as a function of length of cochlear implant use and chronological age. The improvement in performance was manifested as an increase in hit rate and perceptual sensitivity over time. In the younger age group, a greater number of active electrodes predicted better CPT performance. Results from regression analyses indicated a relationship between CPT response criterion and receptive language in the younger age group. However, we failed to uncover any other relations between CPT performance and speech and language outcome measures.

CONCLUSIONS

Our findings suggest that cochlear implantation in prelingually deaf children leads to improved performance on a test of sustained visual processing of numbers over 2 or more years of cochlear implant use. In preschool-age children who use cochlear implants, individuals who are more conservative responders on the CPT show higher receptive language scores than do individuals with more impulsive response patterns. Theoretical accounts of these findings are discussed, including cross-modal reorganization of visual attention and enhanced phonological encoding of visually presented numbers.

Hearing-impaired children in the United Kingdom, I: Auditory performance, communication skills, educational achievements, quality of life, and cochlear implantation

OBJECTIVES

The objectives of this study were to identify variables that are associated with differences in outcome among hearing-impaired children and to control those variables while assessing the impact of cochlear implantation.

STUDY DESIGN

In a cross-sectional study, the parents and teachers of a representative sample of hearing-impaired children were invited to complete questionnaires about children's auditory performance, spoken communication skills, educational achievements, and quality of life. Multiple regression was used to measure the strength of association between these outcomes and variables related to the child (average hearing level, age at onset of hearing impairment, age, gender, number of additional disabilities), the family (parental occupational skill level, ethnicity, and parental hearing status), and cochlear implantation.

RESULTS

Questionnaires were returned by the parents of 2858 children, 468 of whom had received a cochlear implant, and by the teachers of 2241 children, 383 of whom had received an implant. Across all domains, reported outcomes were better for children with fewer disabilities in addition to impaired hearing. Across most domains, reported outcomes were better for children who were older, female, with a more favorable average hearing level, with a higher parental occupational skill level, and with an onset of hearing-impairment after 3 years. When these variables were controlled, cochlear implantation was consistently associated with advantages in auditory performance and spoken communication skills, but less consistently associated with advantages in educational achievements and quality of life. Significant associations were found most commonly for children who were younger than 5 years when implanted, and had used implants for more than 4 years. These children, whose mean (preoperative, unaided) average hearing level was 118 dB, were reported to perform at the same level as nonimplanted children with average hearing levels in the range from 80 dB to 104 dB, depending on the outcome measure.

CONCLUSIONS

When rigorous statistical control is exercised in comparing implanted and nonimplanted children, pediatric cochlear implantation is associated with reported improvements both in spoken communication skills and in some aspects of educational achievements and quality of life, provided that children receive implants before 5 years of age.