Enhancement of expressive language in prelingually deaf children with cochlear implants

The role of age on speech development in subjects with cochlear implants

The cochlear implant has been approved as a method of treating bilateral deep deafness since the 1980s, and since then candidate selection methods have changed several times. Initially, the candidates were only adult patients, and in 1990 the cochlear implant was approved for the first time in children under 2 years of age by the US Food and Drug Administration. In 2000, the same US Administration reduced the limit to one year. The aim of this study was to determine the effect of age at cochlear implantation on speech recognition abilities. Concerning the age groups in which the subjects were assigned to, the best results on the tests were achieved by the group who underwent cochlear implantation at the youngest age. In conclusion, the benefit from cochlear implant in subjects with pre-lingual hearing impairment of the most severe degree has to be stressed and it is much bigger in comparison to individual amplifying hearing aids. If cochlear implant is placed at the youngest age, the results might lead to even 100% of active involvement in the social life of individuals with this kind of impairment.

Preverbal Production and Early Lexical Development in Children With Cochlear Implants: A Longitudinal Study Following Pre-implanted Children Until 12 Months After Cochlear Implant Activation

Studies have shown that children vary in the trajectories of their language development after cochlear implant (CI) activation. The aim of the present study is to assess the preverbal and lexical development of a group of 20 Italian-speaking children observed longitudinally before CI activation and at three, 6 and 12 months after CI surgery (mean age at the first session: 17.5 months; SD: 8.3; and range: 10–35). The group of children with CIs (G-CI) was compared with two groups of normally-hearing (NH) children, one age-matched (G-NHA; mean age at the first session: 17.4 months; SD: 8.0; and range: 10–34) and one language-matched (G-NHL; n = 20; mean age at the first session: 11.2 months; SD: 0.4; and range: 11–12). The spontaneous interactions between children and their mothers during free-play were transcribed. Preverbal babbling production and first words were considered for each child. Data analysis showed significant differences in babbling and word production between groups, with a lower production of words in children with CIs compared to the G-NHA group and a higher production of babbling compared to the G-NHL children. Word production 1 year after activation was significantly lower for the children with CIs than for language-matched children only when maternal education was controlled for. Furthermore, latent class growth analysis showed that children with CIs belonged mainly to classes that exhibited a low level of initial production but also progressive increases over time. Babbling production had a statistically significant effect on lexical growth but not on class membership, and only for groups showing slower and constant increases. Results highlight the importance of preverbal vocal patterns for later lexical development and may support families and speech therapists in the early identification of risk and protective factors for language delay in children with CIs.

Mothers' emotional experiences related to their child's diagnosis of deafness and cochlear implant surgery: Parenting stress and child's language development

OBJECTIVES

The present study aims to assess the emotional experiences, specifically parenting stress, of mothers of children with cochlear implants (CIs), and their children's language development before surgery and at three and six months after CI activation.

METHODS

Twenty mothers of children with CIs were interviewed before their children's surgery about their experiences in connection with the diagnosis of deafness, the surgery and the activation of the CI. The Parenting Stress Index questionnaire and the MacArthur-Bates-Communication Development Inventory were administered before the surgery and at 3 and 6 months after the CI activation.

RESULTS

Analysis of the qualitative data resulting from the interviews showed that the mothers' emotional experiences before the CI surgery were complex. Mothers reported both positive and negative emotions related to deafness, diagnosis and surgery, benefits of the CI, coping strategies and future expectations. The mothers of children with more advanced lexical production six months after CI activation displayed a high frequency of themes related to positive emotions, thoughts and coping strategies before the surgery. Distress on the part of the mothers, perceptions of difficulties in their child and instances of parent-child dysfunctional interaction were negatively and significantly related to the child's language and communication development.

CONCLUSIONS

The findings support the importance of assessing the mother's emotional experience in relation to diagnosis and CI activation before the surgery. IMPLICATIONS FOR CLINICAL PRACTICE ARE DISCUSSED: specifically, the importance of the support offered to the parents, aimed at enhancing both their awareness of their expectations about their child's rehabilitation process and their self-efficacy in supporting the child's adaptation to the use of the CI.

Diverse Linguistic Development in Prelingually Deaf Children with Cochlear Implants

The advent of cochlear implants has enormously improved the quality of sensory perception in deaf children. Notwithstanding these advantages, the current literature shows a substantial variability in language proficiency among implanted children. This case series explores the variability of language acquisition in congenitally deaf children with cochlear implants. We report 4 prelingually deaf children (mean age = 10.5; SD = 1.08), affected by a genetically determined bilateral deafness, due to GJB2 gene mutation Cx26. Each implanted child underwent a systematic assessment of speech perception and production, as well as of lexical, morphologic, and syntactic skills in both comprehension and production. Notwithstanding similar clinical histories and similarly good postimplant pure-tone audiometry, two of the four children fared very poorly in speech audiometry, whereas the other two children gained very good results. We suggest that the language impairment detected in (some) implanted children may not be fully accounted for by pure auditory thresholds and that may be the outcome of concomitant damage to core components of the child's linguistic brain.

Effects of Age at Cochlear Implantation on Vocabulary and Grammar: A Review of the Evidence

Purpose The increasing prevalence of pediatric cochlear implantation over the past 25 years has left little doubt that resulting improvements in hearing offer significant benefits to language development for many deaf children. Furthermore, given the documented importance of access to language from birth, there has been strong support for providing congenitally deaf children with implants as early as possible. Earliest implantation, in many ways, has become the "gold standard" in pediatric cochlear implantation, on the assumption that it is the key to language development similar to that of hearing children. Empirical evidence to support this assumption, however, appears more equivocal than generally is believed. This article reviews recent research aimed at assessing the impact of age at implantation on vocabulary and grammatical development among young implant users. Method Articles published between 2003 and 2018 that included age at implantation as a variable of interest and in which it was subjected to statistical analysis were considered. Effect sizes were calculated whenever possible; we conducted a multivariate meta-analysis to compare outcomes in different language domains. Results Taken together, findings from 49 studies suggest that age at implantation is just one of a host of variables that influence vocabulary and grammatical development, its impact varying with several factors including whether age at implantation is treated as a dichotomous or continuous variable. Results from a meta-analysis showed significant differences across language domains. Conclusion The pattern of results obtained indicates the importance of considering various child, family, and environmental characteristics in future research aimed at determining how early "early implantation" needs to be and the extent to which age at implantation, duration of implant use, and other factors influence language and language-related outcomes. Supplemental Material https://doi.org/10.23641/asha.9789041.

Attention to speech and spoken language development in deaf children with cochlear implants: a 10-year longitudinal study

Early auditory/language experience plays an important role in language development. In this study, we examined the effects of severe-to-profound hearing loss and subsequent cochlear implantation on the development of attention to speech in children with cochlear implants (CIs). In addition, we investigated the extent to which attention to speech may predict spoken language development in children with CIs. We tested children with CIs and compared them to chronologically age-matched peers with normal hearing (NH) on their attention to speech at four time points post implantation; specifically, less than 1 month, 3 to 6 months, 12 months, and 18 months post implantation. We also collected a variety of well-established speech perception and spoken language measures from the children with CIs in a 10-year longitudinal study. Children with CIs showed reduced attention to speech as compared to their peers with NH at less than 1 month post implantation, but a similar degree of attention to speech as their NH peers during later time points. In addition, attention to speech at 3 to 6 months post implantation predicts speech perception in children with CIs. These results inform language acquisition theories and bring insights into our understanding of early severe-to-profound hearing loss on infants' attention to speech skills. In addition, the findings have significant clinical implications for early intervention on hearing loss, which emphasizes the importance of developing strong listening skills. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=f7xiYo3Ua08&feature=youtu.be.

Infant-Directed Speech Enhances Attention to Speech in Deaf Infants With Cochlear Implants

Purpose

Both theoretical models of infant language acquisition and empirical studies posit important roles for attention to speech in early language development. However, deaf infants with cochlear implants (CIs) show reduced attention to speech as compared with their peers with normal hearing (NH; Horn, Davis, Pisoni, & Miyamoto, 2005; Houston, Pisoni, Kirk, Ying, & Miyamoto, 2003), which may affect their acquisition of spoken language. The main purpose of this study was to determine (a) whether infant-directed speech (IDS) enhances attention to speech in infants with CIs, as compared with adult-directed speech (ADS), and (b) whether the degree to which infants with CIs pay attention to IDS is associated with later language outcomes.

Method

We tested 46 infants-12 prelingually deaf infants who received CIs before 24 months of age and had 12 months of hearing experience (CI group), 22 hearing experience-matched infants with NH (NH-HEM group), and 12 chronological age-matched infants with NH (NH-CAM group)-on their listening preference in 3 randomized blocks: IDS versus silence, ADS versus silence, and IDS versus ADS. We administered the Preschool Language Scale-Fourth Edition (PLS-4; Zimmerman, Steiner, & Pond, 2002) approximately 18 months after implantation to assess receptive and expressive language skills of infants with CIs.

Results

In the IDS versus silence block, all 3 groups looked significantly longer to IDS than to silence. In the ADS versus silence block, both the NH-HEM and NH-CAM groups looked significantly longer to ADS relative to silence; however, the CI group did not show any preference. In the IDS versus ADS block, whereas both the CI and NH-HEM groups preferred IDS over ADS, the NH-CAM group looked equally long to IDS and ADS. IDS preference quotient among infants with CIs in the IDS versus ADS block was associated with PLS-4 Auditory Comprehension and PLS-4 Expressive Communication measures.

Conclusions

Two major findings emerge: (a) IDS enhances attention to speech in deaf infants with CIs; (b) the degree of IDS preference over ADS relates to language development in infants with CIs. These results support a focus on input in developing intervention strategies to mitigate the effects of hearing loss on language development in infants with hearing loss.

An Eye Tracking Study on the Perception and Comprehension of Unimodal and Bimodal Linguistic Inputs by Deaf Adolescents

An eye tracking experiment explored the gaze behavior of deaf individuals when perceiving language in spoken and sign language only, and in sign-supported speech (SSS). Participants were deaf (n = 25) and hearing (n = 25) Spanish adolescents. Deaf students were prelingually profoundly deaf individuals with cochlear implants (CIs) used by age 5 or earlier, or prelingually profoundly deaf native signers with deaf parents. The effectiveness of SSS has rarely been tested within the same group of children for discourse-level comprehension. Here, video-recorded texts, including spatial descriptions, were alternately transmitted in spoken language, sign language and SSS. The capacity of these communicative systems to equalize comprehension in deaf participants with that of spoken language in hearing participants was tested. Within-group analyses of deaf participants tested if the bimodal linguistic input of SSS favored discourse comprehension compared to unimodal languages. Deaf participants with CIs achieved equal comprehension to hearing controls in all communicative systems while deaf native signers with no CIs achieved equal comprehension to hearing participants if tested in their native sign language. Comprehension of SSS was not increased compared to spoken language, even when spatial information was communicated. Eye movements of deaf and hearing participants were tracked and data of dwell times spent looking at the face or body area of the sign model were analyzed. Within-group analyses focused on differences between native and non-native signers. Dwell times of hearing participants were equally distributed across upper and lower areas of the face while deaf participants mainly looked at the mouth area; this could enable information to be obtained from mouthings in sign language and from lip-reading in SSS and spoken language. Few fixations were directed toward the signs, although these were more frequent when spatial language was transmitted. Both native and non-native signers looked mainly at the face when perceiving sign language, although non-native signers looked significantly more at the body than native signers. This distribution of gaze fixations suggested that deaf individuals – particularly native signers – mainly perceived signs through peripheral vision.

Receptive and Expressive Language Skills of Children with Five Years of Experience Using a Cochlear Implant

The language of 7 children who had used a cochlear implant for 5 years was evaluated by means of the Clinical Evaluation of Language Fundamentals-3, the Peabody Picture Vocabulary Test-Revised, and the Expressive Vocabulary Subtest of the Test of Word Knowledge. All subjects demonstrated impaired skills relative to normal-hearing children on 1 or more subtests. Variability in performance occurred between subjects and within subjects across subtests. Strengths in semantic skills were evident compared to weaker syntactic and morphological abilities. The nature of the subjects' language impairments is considered with reference to language delay and specific language impairment. The findings support the need for further evaluation of the rate and course of development of language subskills. Investigation of the influences of information processing, and learning styles and strategies, on children's outcomes is also warranted. These findings have implications for implementation of optimal habilitation and education programs for children with cochlear implants.

Classroom Performance of Children with Cochlear Implants in Mainstream Education

Objectives:

We compared classroom performance of children with a cochlear implant (CI) with that of their normal-hearing peers in mainstream education.

Methods:

Thirty-two CI children in mainstream education, congenitally or prelingually deaf, participated in this study, as did 37 hearing classmates. Their teachers filled out 2 questionnaires: the Assessment of Mainstream Performance (AMP) and the Screening Instrument for Targeting Educational Risk (SIFTER). A high Fletcher index and open-set speech perception scores were obtained.

Results:

The children with CIs scored above average on the AMP and sufficiently well in all but one area (communication) of the SIFTER questionnaire. Class rankings did not differ significantly between the CI students and their normal-hearing peers. Overall, the normal-hearing group outperformed the CI group. The classroom performance of CI children correlated negatively with duration of deafness and age at implantation. All longitudinal audiological data of the CI children showed improvement in open-set speech recognition.

Conclusions:

Although the results are encouraging, the CI group scored significantly less well than their normal-hearing peers on most questionnaire domains of both the AMP and the SIFTER. The most important variables for the outcome in this study were age at implantation and duration of deafness.

Vowel space characteristics of speech directed to children with and without hearing loss

PURPOSE

This study examined vowel characteristics in adult-directed (AD) and infant-directed (ID) speech to children with hearing impairment who received cochlear implants or hearing aids compared with speech to children with normal hearing.

METHOD

Mothers' AD and ID speech to children with cochlear implants (Study 1, n=20) or hearing aids (Study 2, n=11) was compared with mothers' speech to controls matched on age and hearing experience. The first and second formants of vowels /i/, /ɑ/, and /u/ were measured, and vowel space area and dispersion were calculated.

RESULTS

In both studies, vowel space was modified in ID compared with AD speech to children with and without hearing loss. Study 1 showed larger vowel space area and dispersion in ID compared with AD speech regardless of infant hearing status. The pattern of effects of ID and AD speech on vowel space characteristics in Study 2 was similar to that in Study 1, but depended partly on children's hearing status.

CONCLUSION

Given previously demonstrated associations between expanded vowel space in ID compared with AD speech and enhanced speech perception skills, this research supports a focus on vowel pronunciation in developing intervention strategies for improving speech-language skills in children with hearing impairment.

Mandarin lexical tones identification among children with cochlear implants or hearing aids

OBJECTIVES

Mandarin Chinese is a lexical tone language that has four tones, with a change in tone denoting a change in lexical meaning. There are few studies regarding lexical tone identification abilities in deafened children using either cochlear implants (CIs) or hearing aids (HAs). Furthermore, no study has compared the lexical tone identification abilities of deafened children with their hearing devices turned on and off. The present study aimed to investigate the lexical tone identification abilities of deafened children with CIs or HAs.

METHODS

Forty prelingually deafened children (20 with CIs and 20 with HAs) participated in the study. In the HA group, 20 children were binaurally aided. In the CI group, all of the children were unilaterally implanted. All of the subjects completed a computerized lexical tone pairs test with their hearing devices turned on and off. The correct answers of all items were recorded as the total score and the correct answers of the tone pairs were recorded as subtotal scores.

RESULTS

No significant differences in the tone pair identification scores were found between the CI group and HA group either with the devices turned on or off (t=1.62, p=0.11; t=1.863, p=0.07, respectively). The scores in the aided condition were higher than in the unaided condition regardless of the device used (t=22.09, p<0.001, in the HA group; t=20.20, p<0.001, in the CI group). Significantly higher scores were found in the tone pairs that contained tone 4. Age at fitting of the devices was correlated with tone identification abilities in both the CI and HA groups. Other demographic factors were not correlated with tone identification ability.

CONCLUSIONS

The hearing device, whether a hearing aid or cochlear implant, is beneficial for tone identification. The lexical tone identification abilities were similar regardless of whether the subjects wore a HA or CI. Lexical tone pairs with different durations and dissimilar tone contour patterns are more easily identified. Receiving devices at earlier age tends to produce better lexical tone identification abilities in prelingually deafened children.

Speech perception outcomes after cochlear implantation in prelingually deaf infants: the Western Sicily experience

OBJECTIVES

To describe audiometric characteristics and speech perception performances of prelingually deaf Sicilian children after cochlear implantation; to identify the influence of cochlear implant (CI) user and family's characteristics on speech recognition and intelligibility outcomes.

METHODS

Twenty-eight infants with a congenital or acquired hearing impairment and implanted before the 3rd year of life were studied; all children suffered from bilateral sensorineural hearing loss (SNHL) with evidence of lack of hearing aids benefit and no evidence of intellectual disability. The study of the main characteristics associated with CI user and family's profile was performed with a clinical assessment including pre-implant and post-implant (1, 3, 6, 12 and 18 months) behavioural audiometry (evaluating average threshold for the frequencies 0.5, 1, 2 and 4KHz) and speech recognition tests (IT-MAIS, MUSS, CAP and SIR).

RESULTS

Our cohort was characterized by an early diagnosis of SNHL (5.77 and 12.17 months for congenital and acquired HL respectively), a short length of deafness (average=6.78 months) and an implantation before the 3rd year of life (mean=24.25 months; range from 10 to 36). Analysis of audiometric threshold revealed a significantly improved capacity to detect sounds within the conversational speech spectrum after 12 months from implantation (r=0.99; p<0.001). The main speech recognition test evidenced speech perception and speech intelligibility performances (CAP median value of 3; SIR category=3 in 46.42%) equal to those children with same characteristics reported by literature. With the exception of 'daily CI use' (p<0.001), none of the variables associated with CI user and family's profile resulted significant predictor of speech perception improvement.

CONCLUSIONS

This work demonstrates that all children of our cohort, with an early diagnosis of SNHL and a CI surgery performed before the 3rd year of life, presented a progressive audiometric and speech improvement through the first 12-18 months after cochlear implantation. The study also highlights that, differently from the others variables studied, a continuous CI use influences significantly speech perception and recognition outcomes.

Current and planned cochlear implant research at New York University Laboratory for Translational Auditory Research

The Laboratory of Translational Auditory Research (LTAR/NYUSM) is part of the Department of Otolaryngology at the New York University School of Medicine and has close ties to the New York University Cochlear Implant Center. LTAR investigators have expertise in multiple related disciplines including speech and hearing science, audiology, engineering, and physiology. The lines of research in the laboratory deal mostly with speech perception by hearing impaired listeners, and particularly those who use cochlear implants (CIs) or hearing aids (HAs). Although the laboratory's research interests are diverse, there are common threads that permeate and tie all of its work. In particular, a strong interest in translational research underlies even the most basic studies carried out in the laboratory. Another important element is the development of engineering and computational tools, which range from mathematical models of speech perception to software and hardware that bypass clinical speech processors and stimulate cochlear implants directly, to novel ways of analyzing clinical outcomes data. If the appropriate tool to conduct an important experiment does not exist, we may work to develop it, either in house or in collaboration with academic or industrial partners. Another notable characteristic of the laboratory is its interdisciplinary nature where, for example, an audiologist and an engineer might work closely to develop an approach that would not have been feasible if each had worked singly on the project. Similarly, investigators with expertise in hearing aids and cochlear implants might join forces to study how human listeners integrate information provided by a CI and a HA. The following pages provide a flavor of the diversity and the commonalities of our research interests.

The effects of age and infant hearing status on maternal use of prosodic cues for clause boundaries in speech

PURPOSE

The present study examined the effects of age and hearing status of a child on maternal use of pitch change, preboundary vowel lengthening, and pause duration, all of which are prosodic cues correlated with clause boundaries in infant-directed speech.

METHOD

Mothers' speech to infants with normal hearing (NH; n = 18), infants who are profoundly deaf with a cochlear implant (HI; n = 9), and an adult experimenter were recorded at 2 time periods separated by 6 months. NH infants were matched to HI infants by chronological age or hearing experience. Fundamental frequency of pre- and postboundary vowels, vowel duration, and pause duration between utterances was measured.

RESULTS

Results demonstrated that mothers (a) exaggerated prosodic characteristics in infant-directed speech regardless of infants' hearing status; (b) tailored preboundary vowel lengthening to infants' hearing experience rather than to chronological age; and (c) decreased exaggeration of pause duration over time.

CONCLUSIONS

The results suggest that acoustic cues correlated with clause boundaries are available in maternal speech to HI infants. Their exaggeration relative to adult-directed speech suggests that mothers' use of infant-directed speech is a natural behavior regardless of infant hearing status. Finally, mothers modify speech prosody according to their children's age and hearing experience.

Children with cochlear implants and developmental disabilities: a language skills study with developmentally matched hearing peers

The number of children receiving cochlear implants (CIs) with significant disabilities in addition to their deafness has increased substantially. Unfortunately, children with additional disabilities receiving CIs have largely been excluded from studies on cochlear implant outcomes. Thus limited data exists on outcomes in this population to guide pre-implant counseling for anticipated benefits. The study objectives were: (1) evaluate differences in post-cochlear implant language skills between children with cochlear implants and developmental disabilities and age/cognitively matched controls; (2) quantify possible discrepancies between language level and cognitive level. Fifteen children with a developmental disability who received a CI were matched 1:1 on nonverbal cognitive ability and age to hearing controls. Language was evaluated using Preschool Language Scale-IV and reported as language quotients. Multivariable mixed models for matched pairs analyzed differences in language levels between groups. No significant differences were seen between CI and control groups regarding insurance, maternal education, or family income level. Results of the multivariable models indicated that compared to matched controls, the CI group had significantly lower mean receptive (24.6 points, p=0.002) and mean expressive (21.9 points, p=0.001) language quotients after controlling for confounders such as number of therapies and weekly hours in therapy. Significant discrepancies between language level and cognitive level were seen among CI participants only. Compared to age- and cognitively matched controls, children with CIs had significantly lower language levels with delays disproportionate to their cognitive potential. Mechanisms behind this performance-functional gap need to be understood to deliver appropriate intervention strategies for this special population.

Children with cochlear implants: the communication journey

Cochlear implantation is now a well-established procedure for profoundly deaf children providing access to speech through hearing for many of them. Much attention has focused on which communication mode to adopt with this group of children but very little work has looked at the choices that parents make before and after cochlear implantation. This study, following on from two earlier studies, looked in depth at the experiences of 12 families. It finds that parents choose the most effective way of communicating with their child but retain as their goal, the development of oral communication skills. For many this is a journey in which different approaches are utilised at various stages in the child's development.

Language achievement in children who received cochlear implants between 1 and 2 years of age: group trends and individual patterns

This study examined receptive and expressive vocabulary and grammar achievement of French-speaking children (n = 27) who received a cochlear implant (CI) between the age of 1 and 2. Standardized measures of language achievement were administered and the language levels attained by children with CIs were compared with that of the normative sample of same-age hearing peers for each measure. As a group, children exhibited language levels within normal limits in all standardized language measures. Examination of individual patterns revealed four different language profiles ranging from normal language levels in all domains to general language delay. Half the participants displayed language levels on par with similar-age peers at the word level; less than half the children obtained average performance at the sentence level. In three of these profiles, comprehension of sentences was impaired. Moreover, the age at implantation was not associated with language achievement. Findings suggest that receiving a CI between the age of 1 and 2 years does not ensure that language abilities will be within normal limits after up to 6 years of experience with the implant.

Quality of life for children with cochlear implants: perceived benefits and problems and the perception of single words and emotional sounds

PURPOSE

This study examined children's self-reported quality of life with a cochlear implant as related to children's actual perceptions of speech and the emotional information conveyed by sound. Effects of age at amplification with hearing aids and fitting of cochlear implants on perceived quality of life were also investigated.

METHOD

A self-reported quality of life questionnaire and assessments of speech perception (single words) and emotion identification were administered to a sample of 37 children with cochlear implants who were congenitally deaf, who were 5-14 years of age, and who all used spoken language.

RESULTS

The children reported significant improvement in quality of life because of their cochlear implants, and they also reported low levels of concern about typical problems associated with wearing an implant. The children's perceived quality of life did not significantly predict speech perception performance at the single word level. In contrast, increased quality of life predicted better performance on the emotion identification task. Age at first use of amplification predicted perceived quality of life.

CONCLUSIONS

The findings regarding age reinforce the importance of early detection and intervention for children's positive quality of life with cochlear implants later in childhood.

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.

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.

Classroom Performance and Language Development of CI Students Placed in Mainstream Elementary School

OBJECTIVE

Investigation of the relation between classroom performance and language development of cochlear implant (CI) students in mainstream education. Structural analyses of assessment of mainstream performance (AMP) and Screening Instrument For Targeting Educational Risk (SIFTER) instruments.

STUDY DESIGN

Cross-sectional instrument and language development analyses.

SETTING

Tertiary university medical center.

PATIENTS

Twenty-six CI children in elementary school with congenital or prelingual deafness were included. At the time of this study, mean period of multichannel CI use was 5.3 years, and children's ages ranged from 6.5 to 12.8 years.

MAIN OUTCOME MEASURE

Assessment of mainstream performance and SIFTER instruments measured classroom performance and language development were measured by means of Reynell and Schlichting tests.

RESULTS

Assessment of mainstream performance and SIFTER domains showed good reliability (Cronbach alpha >0.6), but factor analyses only showed the expected instrument structure in the AMP. In both questionnaires and within all domains, individual variability is detected. Spearman's correlation analyses showed the probable explanation of individual questionnaire variability by language test results (p value mostly <0.01). The AMP and SIFTER instruments showed a predictive capacity for language development, based upon general linear model univariate and linear regression analyses.

CONCLUSION

Individual classroom performance, measured by AMP and SIFTER questionnaires, of CI children in mainstream education varies. Correlation analyses showed strong significant relation between questionnaire results (classroom performance) and both expressive and receptive language test results (Schlichting and Reynell tests). Structural questionnaire analyses of the AMP and SIFTER demonstrated good reliability. The predictive value of the AMP can monitor the actual linguistic functioning of the child.

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.

Normal hearing and language development in a deaf-born child

BACKGROUND

Congenital deafness leads to major problems in speech, language, education, and social integration. Neonatal hearing screening and cochlear implantation now allow early hearing restoration. This article reports on a prospective longitudinal study of the first infant ever who received two cochlear implants in the prelexical period of her life.

METHODS

The first deaf-born girl ever who received two implants at the ages of 5 and 15 months, respectively, was followed-up with repeated and detailed quantitative assessments from birth to 4 years of age. This consisted of 1) audiologic evaluation (audiometry, speech audiometry, and Categories of Auditory Performance score), 2) linguistic evaluation (monthly video analyses and tests of vocabulary, language skills, grammar, and intelligibility of the child's speech), and 3) descriptive assessment of the educational setting.

RESULTS

All results lie within the 95% confidence interval of hearing peers. The audiologic performance lies at or above average from age 2 years onward. The child started babbling at the normal age of 8 months. Her linguistic skills increased from low percentiles before age 2 to above average from age 2 for comprehension and from age 3 for production. The grammar and intelligibility of the child's speech increased from low percentiles to average at age 4. The girl entered preschool at the normal age of 2.5 years, and this with only very limited special assistance.

CONCLUSION

This case illustrates the fact that congenital deafness no longer has to lead to abnormal hearing and abnormal speech development. It opens the debate of the ethics of not implanting a deaf child in the first few months of life.

Speech intelligibility of Mandarin-speaking deaf children with cochlear implants

OBJECTIVE

Speech intelligibility, the extent to which the speakers can be understood verbally by their listeners, is an evaluator for the effectiveness of cochlear implantation. Thus, our goals were to evaluate the result of a tonal language through comparing the speech intelligibility between normal-hearing and implanted children who speak Mandarin, and to evaluate the relationship between speech intelligibility and duration of implants use. The effects of the age at implantation were also evaluated.

METHODS

Twenty-six children (mean age of 5.9 years), who were congenitally deaf and implanted age at 3.5 years, were compared with 26 normal-hearing children (mean age of 5.84 years). The average post-implanted time was more than 6 months. Speech intelligibility was represented with the speech intelligibility ratings (SIR) and the correct percentage of dictation. The relationships between speech intelligibility, age at implantation and duration of implant were evaluated by linear regression analysis.

RESULTS

Speech intelligibility of most subjects ranked from SIR category 3-5. The average correct perception rate (CI group/normal group) of words, consonants, vowels, and tones were 42.5%, 64.9%, 73.5%, and 72.3%, respectively. These differences were statistically significant (p<0.001). Speech intelligibility was positively correlated with age only in the normal-hearing group. Speech intelligibility in the implanted group was negatively correlated with age at implantation but positively correlated with the duration of implant.

CONCLUSIONS

Speech intelligibility of tonal language was poorer in implanted children than normal-hearing children, but their communication outcomes were satisfactory when measured with SIR. Speech intelligibility is better if the age at implantation is younger or duration of implants use is longer.

Mandarin Speech Perception in Nucleus CI 24 Implantees Using MAPs Based on Neural Response Telemetry

The purpose of this study is to compare speech perception performance in Mandarin-speaking Nucleus CI24 implantee using standard behavior MAPs and NRT-based MAPs. Eight Nucleus CI24 users (5 years and older) participated in the study. They all fulfilled the following criteria: (1) behavioral MAP and NRT thresholds can be reliably obtained; (2) had more than 18 functioning electrodes; (3) had at least 6 months experience using CI. All subjects received speech evaluation under three different MAPs: a traditional behavioral MAP, a MAP predicted from the NRT thresholds of the E22 (electrode 22), E19, E15, E11, E8, E5, E1 and a combined MAP based on the information of NRT thresholds and behavioral threshold/comfortable levels of the E11. The speech evaluation package included word recognition test in quiet, in noise, and a Mandarin sentence test in quiet. Results showed that three MAPs are similar in some subjects, but different in other subjects. Compared to the NRT MAPs, the combined MAPs are more similar to the behavioral MAPs. There was no significant difference in the mean score of the word recognition test in quiet, in noise and sentence test under these three MAP conditions. In conclusion, although the behavioral MAPs and the NRT-based MAPs are not identical, the speech performance of Mandarin-speaking CI24 implantee using MAPs predicted from NRT thresholds appeared to be no worse than the traditional behavioral MAPs. Therefore, in certain cases that behavioral MAPs are difficult to obtain (such as in very young or multiple handicapped children), NRT-based MAPs may serve reliably as an initial estimation.

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.

Assessing candidate children for cochlear implantation with the Nottingham Children's Implant Profile (NChIP): the first 200 children

BACKGROUND/OBJECTIVE

Nottingham Children's Implant Profile (NChIP) is a profile designed to assess candidate children for cochlear implantation. It includes the demographic details of the children (chronological age and duration of deafness), medical and radiological conditions, the outcomes of audiological assessments, language and speech abilities, multiple handicaps or disabilities, family structure and support, educational environment, the availability of support services, expectations of the family and deaf child, cognitive abilities, and learning style. The aim of the present study is to present the NChIP data obtained on the first 200 children implanted in the same cochlear implant programme and evaluate NChIP's use in the selection phase of cochlear implantation.

PATIENTS

The study assessed 200 profoundly deaf children. Fifty-six children (28%) were deafened by meningitis, 132 (66%) were born deaf, and 12 (6%) were deafened from other causes (head injury, viral infection, progressive deafness).

RESULTS

Chronological age at the time of assessment (before implantation) was the most common factor of major concern (9% of the children studied) and the pre-implant language and speech abilities of the children was the most common factor of mild to moderate concern, affecting 63% of the children. The second most common factor of mild to moderate concern was duration of deafness (37%) and the third was the learning style of the children (33%). Availability of support services was the least factor of concern as 179 children (90%) did not have any problems in this area.

CONCLUSIONS

Earlier identification of deafness (by universal neonatal hearing screening programs) may reduce age at implantation and duration of deafness as areas of concern in the future. However, the pre-implant language and speech abilities of the candidate children, the gap between chronological and language age, and the learning style of children are now emerging as key areas of research in the field. NChIP was found to be a very useful casework tool in the initial evaluation of the deaf children promoting and enhancing interdisciplinary teamwork across the different professionals. NChIP was also used as part of the decision-making process by the cochlear implant programme professionals and as a counselling tool for the parents. Finally, NChIP has helped to identify those children and families who need additional support. In the case of recently established paediatric cochlear implant programmes it would be a 'neutral' yet sensitive way of promoting good interdisciplinary collaboration and also peer support within team discussions when selecting children for cochlear implantation.

Predicting speech perception outcomes following cochlear implantation using Nottingham children's implant profile (NChIP)

BACKGROUND/OBJECTIVE

Nottingham children's implant profile (NChIP) is a systematic framework to assess deaf children before implantation taking into account not only the well-known factors (age, duration of deafness) but also family and support services, expectations, children's cognitive abilities and learning style. The aim of the present paper is to assess the predictive value of the NChIP in the long-term outcomes of implanted children.

PATIENTS

This prospective and longitudinal study involved 51 profoundly deaf children, implanted within the same paediatric cochlear implant programme. All children were pre-lingually deaf with age at onset of deafness <2 years and age at implantation <6 years. Three and 4 years following implantation all children were assessed using two measures of speech perception. No child was lost to follow-up and no child was excluded from the study for any reason.

RESULTS

The most constant predictor of the outcomes was children's learning style explaining upto 29% of the variance. Other significant predictors of the outcome were shorter duration of deafness, young age at implantation and family structure/support.

CONCLUSIONS

Intrinsic factors in children and how well they communicate with their environment are of paramount importance to the outcome following implantation. The predictive value of NChIP has been demonstrated and the most important predictors of the outcome were children's learning style, short duration of deafness, young age at implantation, and family structure/support.

Changes of voice and articulation in children with cochlear implants

OBJECTIVE

The different speech sounds are formed by the primary voice signal and by the shape of the articulation tract. With this mechanism, specific overtones, the formants, are generated for each vowel. The objective of this study was to investigate the fundamental frequency (F0) of the voice signal and the first three formants (F1-F3) as a parameter of the articulation in prelingually deafened children at different timepoints after cochlear implantation (CI) compared with children with normal speech development.

METHODS

Using the Kay CSL 4300B, the fundamental frequency and the formants F1-F3 of the Swiss-German vowel /a/ were investigated at different timepoints after CI in 20 prelingually deafened children aged 3.8-10.2 years by means of spectrographic and linear predictive coding (LPC) analysis.

RESULTS

Children who had been operated before their fourth birthday showed no significant deviation in their fundamental frequency from age- and sex-matched peers, whereas a significant difference was documented in children who were older at the time of implantation. The first formant was very stable in every child and showed only discrete deviations from the normal range. The second and third formants, however, developed a broader scatter, but there was no systematic deviation of these formants to higher or lower values. The F1:F2 ratio was normal in children who were implanted at the age of up to 4 years and more centralized in children who were older at the time of implantation, as is known from the hearing impaired.

CONCLUSIONS

Our results indicate that prelingually deaf children who receive a cochlear implant before their fourth birthday attain a better acoustic control over their speech, normalizing their fundamental frequencies and improving their articulatory skills.

Rapid development of cortical auditory evoked potentials after early cochlear implantation

The aim of our research was to estimate the time course of development and plasticity of the human central auditory pathways following cochlear implantation. We recorded cortical auditory-evoked potentials in 3-year-old congenitally deaf children after they were fitted with cochlear implants. Immediately after implantation cortical response latencies resembled those of normal-hearing newborns. Over the next few months, the cortical evoked responses showed rapid changes in morphology and latency that resulted in age-appropriate latencies by 8 months after implantation. Overall, the development of cortical response latencies for the implanted children was more rapid than for their normal-hearing age-matched peers. Our results demonstrate a high degree of central auditory system plasticity during early human development.

Receptive and expressive language skills of 106 children with a minimum of 2 years' experience in hearing with a cochlear implant

OBJECTIVE

The aim of the study was to assess the speech development of children with at least 2 years' hearing experience with a cochlear implant (CI).

METHODS

One hundred and six children were tested, all of whom had used the CI for at least 2 years. Receptive and expressive language development were tested using the scales of early communication skills for hearing-impaired children after Geers and Moog and the Reynell developmental language scales III. In addition, free-field audiometry was performed. Pre-postoperative measurements were compared statistically, and a linear regression analysis was carried out.

RESULTS

Clear improvements in the gain in functional hearing 2 years after receiving the CI as well as clear improvements in both speech perception and speech production were ascertained. All deviations were statistically highly significant (P<0.000). The receptive and expressive speech test results correlate positively to a great extent. The results of logistic regressive analysis indicate that the speech production measured depends decisively on age at implantation, age at time of test, speech production before implantation, and additional handicaps.

CONCLUSION

Based on the conception of the WHO, a statistically significant improvement of both impairment and disability can be confirmed. In the present study, the regression analysis established the age at implantation as the most important prognostic factor. While the percentage of children with good speech development is larger with early implanted children than with late implanted children, some of the children among the early implanted group show unsatisfactory speech development of unknown origin. Improvements in speech development are likely to be achieved when more children are diagnosed and implanted early. This finding urgently requires the introduction of a general newborn screening program. Thorough anamnesis and assessment during parent counseling of the manifold factors described are a prerequisite for the precise estimation of the difficulties to be met and the expected effectiveness of the implant in each individual case.

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.

Vocabulary acquisition rate after pediatric cochlear implantation and the impact of age at implantation

OBJECTIVE

studies of early vocabulary development after pediatric cochlear implantation show growth rates that approach normality. Do these growth rates continue to rise over time and, therefore, allow a 'catch up' with ideal scores for age, or do they decline after an initial peak. Could age at implantation be a decisive factor in that process?

DESIGN

retrospective study (mean follow-up 4 years).

PATIENTS

pre-lingually deaf children implanted between 1988 and1999, who serially performed Peabody Picture Vocabulary Test-Revised (PPVT), (37 patients) and Expressive One-word Picture Vocabulary Test-Revised (EOWPVT), (35 patients).

OUTCOME MEASURES

the mean rates of age equivalent scores were determined for the whole follow-up period and analyzed further for two post-implant periods (the two halves of follow-up duration of individual patients). After sub-grouping by age at implantation (younger or older than 5 years old), the same analysis was executed for each subgroup.

RESULTS

the mean EOWPVT rate of the earlier period was higher than that of the later period (1.33 vs. 0.67, P<0.01) and the mean PPVT rate of the earlier period was higher than that of the later period (0.72 vs. 0.5). The latter difference was not statistically significant (P>0.05). Within subgroups by age at implantation, the PPVT mean rates were stable for younger implanted patients (0.56 for both periods) and dropped for the older implanted sub-group (0.87-0.43, P>0.05). The EOWPVT mean rates declined significantly for the older patients group (1.72-0.55, P<0.01) but insignificantly for the younger patients (0.99-0.77, P>0.05).

CONCLUSIONS

vocabulary acquisition rates decline in the post-implantation period. This is more pronounced with older implanted children and the EOWPVT rates. This information on the time course development of vocabulary after implantation would be valuable in counseling and planning habilitation in addition to candidate selection.

Language evolution in children with cochlear implants

The capacity to incorporate significant words into the existing vocabulary and to use these words to form sentences with more mature syntactic structures emerges over a considerable time course in young deaf children who have undergone a cochlear implantation. The purpose of this follow-up study is to document the nature and time span of language production--in morphosyntactic and lexical skills--when a child's first experience with language sounds is provided artificially through electrical stimulation. To examine the development of these two aspects of linguistic processing, five deaf French children, all enrolled in similar postimplantation educational settings, were individually assessed at 6-month intervals over a period of 18 months. Computerized analyses were derived from their spontaneous speech in a 20-min standardized play session. Results for mean length of utterance and vocabulary revealed gradually improving performance for most children, in spite of the generally low starting point. Both measures of production nevertheless remained well below the norms established for normally hearing children. Although the achievement of higher production scores, which underlies more effective interpersonal exchanges, is evident after only 1 year of device use, it is clear that improvement does not always occur at the same pace, as shown by two of the children. This emphasizes the importance of longitudinal studies in documenting intersubject variability and intrasubject stability throughout the experience with an implant.

Cochlear implants in children

Cochlear implants are electronic prostheses that provide a high quality sense of hearing to severely and profoundly deaf children and adults. As improvements in surgical technique and device performance have occurred, indications for implantation have expanded.

Relationships among speech perception, production, language, hearing loss, and age in children with impaired hearing

Eighty-seven primary-school children with impaired hearing were evaluated using speech perception, production, and language measures over a 3-year period. Forty-seven children with a mean unaided pure-tone-average hearing loss of 106 dB HL used a 22-electrode cochlear implant, and 40 with a mean unaided pure-tone-average hearing loss of 78 dB HL were fitted with hearing aids. All children were enrolled in oral/aural habilitation programs, and most attended integrated classes with normally hearing children for part of the time at school. Multiple linear regression was used to describe the relationships among the speech perception, production, and language measures, and the trends over time. Little difference in the level of performance and trends was found for the two groups of children, so the perceptual effect of the implant is equivalent, on average, to an improvement of about 28 dB in hearing thresholds. Scores on the Peabody Picture Vocabulary Test (PPVT) and the Clinical Evaluation of Language Fundamentals showed an upward trend at about 60% of the rate for normally hearing children. Rates of improvement for individual children were not correlated significantly with degree of hearing loss. The children showed a wide scatter about the average speech production score of 40% of words correctly produced in spontaneous conversations, with no significant upward trend with age. Scores on the open-set Consonant-Nucleus-Consonant (CNC) monosyllabic word test and the Bench-Kowal-Bamford (BKB) sentence test were strongly related to language level (as measured by an equivalent age on the PPVT) and speech production scores for both auditory-visual and auditory test conditions. After allowing for differences in language, speech perception scores in the auditory test condition showed a slight downward trend over time, which is consistent with the known biological effects of hearing loss on the auditory periphery and brainstem. Speech perception scores in the auditory condition also decreased significantly by about 5% for every 10 dB of hearing loss in the hearing aid group. The regression analysis model allows separation of the effects of language, speech production, and hearing levels on speech perception scores so that the effects of habilitation and training in these areas can be observed and/or predicted. The model suggests that most of the children in the study will reach a level of over 90% sentence recognition in the auditory-visual condition when their language becomes equivalent to that of a normally hearing 7-year-old, but they will enter secondary school at age 12 with an average language delay of about 4 or 5 years unless they receive concentrated and effective language training.