Effects of early auditory experience on the spoken language of deaf children at 3 years of age

Language, Mental State Vocabulary, and False Belief Understanding in Children With Cochlear Implants

Purpose

This study examined false belief understanding and its predictors in school-age children who are deaf with cochlear implants and who use spoken language.

Method

False belief understanding was measured through an explanation-of-action task in 30 children between the ages of 3 and 12 years who used cochlear implants. Children told a wordless story from which expressive syntax and vocabulary scores were obtained. Scores on the false belief explanation task were then correlated with a variety of language and vocabulary variables, and regression analyses were completed to ascertain significant predictors of theory of mind (ToM) performance.

Results

Children’s false belief explanation of anomalous action was best predicted by age; general language ability; and spontaneous use of mental state vocabulary, specifically, cognitive vocabulary. Even the youngest children demonstrated awareness of others' mental states and made reference to them in explaining mistaken actions, supporting the assertion by M. Marschark, V. Green, G. Hindmarsh, and S. Walker (2000) that children who are deaf are not lacking a ToM.

Clinical Implications

Results of this study suggest that ToM maturation in deaf children might be facilitated by developing general spoken language skills as well as understanding and using cognitive and emotional language. These findings might also extend to children with normal hearing who are also at risk for ToM deficits (e.g., children on the autistic spectrum and children with pragmatic language delays).

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.

Developmental hearing loss disrupts synaptic inhibition: implications for auditory processing

Hearing loss during development leads to central deficits that persist even after the restoration of peripheral function. One key class of deficits is due to changes in central inhibitory synapses, which play a fundamental role in all aspects of auditory processing. This review focuses on the anatomical and physiological alterations of inhibitory connections at several regions within the central auditory pathway following hearing loss. Such aberrant inhibitory synaptic function may be linked to deficits in encoding binaural and spectral cues. Understanding the cellular changes that occur at inhibitory synapses following hearing loss may provide specific loci that can be targeted to improve function.

Development and plasticity of intra- and intersensory information processing

The functional architecture of sensory brain regions reflects an ingenious biological solution to the competing demands of a continually changing sensory environment. While they are malleable, they have the constancy necessary to support a stable sensory percept. How does the functional organization of sensory brain regions contend with these antithetical demands? Here we describe the functional organization of auditory and multisensory (i.e., auditory-visual) information processing in three sensory brain structures: (1) a low-level unisensory cortical region, the primary auditory cortex (A1); (2) a higher-order multisensory cortical region, the anterior ectosylvian sulcus (AES); and (3) a multisensory subcortical structure, the superior colliculus (SC). We then present a body of work that characterizes the ontogenic expression of experience-dependent influences on the operations performed by the functional circuits contained within these regions. We will present data to support the hypothesis that the competing demands for plasticity and stability are addressed through a developmental transition in operational properties of functional circuits from an initially labile mode in the early stages of postnatal development to a more stable mode in the mature brain that retains the capacity for plasticity under specific experiential conditions. Finally, we discuss parallels between the central tenets of functional organization and plasticity of sensory brain structures drawn from animal studies and a growing literature on human brain plasticity and the potential applicability of these principles to the audiology clinic.

Management of otitis media-related diseases in children with a cochlear implant

CONCLUSION

In all, 4 of 19 children with a cochlear implant (CI) with otitis media developed cholesteatoma. The insertion of a CI may interfere with normal mastoid pneumatization, stimulate mucosa as foreign body, or act as a nidus of infection. Regular follow-up is necessary for children with a CI at the prevalent ages of otitis media. Antibiotic treatment is suggested whenever acute otitis media is suspected, to prevent chronic progress of infection, cholesteatoma, or even meningitis.

OBJECTIVE

To evaluate treatment modality and outcomes of otitis media-related diseases in children with a CI.

PATIENTS AND METHODS

This was a retrospective case review in a tertiary referral center of Taipei Medical University, Chi Mei Medical Center. All patients had a history of otitis media or related disease in the implanted ear. Treatments included antibiotics, tympanotomy, and tympanomastoidectomy.

RESULTS

In all, 19 of 186 children with a CI were identified as having otitis media, and 4 of them as having cholesteatoma. Among the others, 10 were identified as having acute otitis media, 4 as having middle ear effusion, and 1 as having mastoiditis in the implanted ear. Surgery was performed in children with cholesteatoma and mastoiditis. The CIs of three children were eventually explanted to eradicate cholesteatoma.

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.

Spoken language scores of children using cochlear implants compared to hearing age-mates at school entry

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

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.

Theory of mind and language in children with cochlear implants

Thirty children with cochlear implants (CI children), age range 3-12 years, and 30 children with normal hearing (NH children), age range 4-6 years, were tested on theory of mind and language measures. The CI children showed little to no delay on either theory of mind, relative to the NH children, or spoken language, relative to hearing norms. The CI children showed a slightly atypical sequence of acquisition of theory of mind concepts. The CI children's theory of mind performance was associated with general syntactic proficiency more than measures of complement syntax, and with time since implantation more than age at implantation. Results suggest that cochlear implantation can benefit spoken language ability, which may then benefit theory of mind, perhaps by increasing access to mental state language.

Neonatal nicotine exposure impairs development of auditory temporal processing

Accurate temporal processing of sound is essential for detecting word structures in speech. Maternal smoking affects speech processing in newborns and may influence child language development; however, it is unclear how neonatal exposure to nicotine, present in cigarettes, affects the normal development of temporal processing. The present study used the gap-induced prepulse inhibition (gap-PPI) of the acoustic startle response to investigate the effects of neonatal nicotine exposure on the normal development of gap detection, a behavioral testing procedure of auditory temporal resolution. Neonatal rats were injected twice per day with saline (control), 1mg/kg nicotine (N-1 mg) or 5 mg/kg nicotine (N-5 mg) from postnatal day 8-12 (P8-P12). During the first month after birth, rats showed poor gap-PPI in all three groups. At P45 and P60, gap-PPI in control rats improved significantly, whereas rats exposed to nicotine exhibited less improvement. At P60, the gap-detection threshold in the N-5 mg group was significantly higher than in the control group, suggesting that neonatal nicotine exposure affects the normal development of gap-detection acuity. Additionally, 1h after receiving an acute nicotine injection (1 mg/kg), gap-PPI recorded in adult rats from the N-5 mg group showed a temporary significant improvement. These results suggest that neonatal nicotine exposure reduces gap-PPI implying an impairment of the normal development of auditory temporal processing by inducing changes in cholinergic systems.

Education and training of young people who grew up with cochlear implants

AIMS

We want to provide new qualitative and quantitative data on the long-term impact of cochlear implantation (CI) on educational placement, vocational outcomes and employment status of hearing-impaired adolescents and young adults.

METHODS

52 cochlear implant users (age: 12-21 years) and a control group of 155 normal-hearing peers participated in structured interviews on their educational level, achievement, satisfaction with their vocational placement and correspondence between career aspiration and actual occupation.

RESULTS

The educational level of CI-using pupils did not differ from the Austrian population. More than 80% of school-aged children attended mainstream schools. The educational level was positively correlated to the educational level of the father and performance on numbers in an auditory speech test. Nevertheless, parents of pupils with cochlear implants rated the future career chances of their children significantly less optimistic than parents of normal-hearing peers. More than 60% of secondary post-graduates (alumni) completed their education in mainstream schools, two studied at university. 12 out of 13 participants, who required work, were employed, 75% of them with regular contracts. Although all CI-users reported high satisfaction with their work, the correspondence between career aspiration and actual occupation was significantly lower for CI-users compared to normal-hearing peers.

CONCLUSION

The majority of CI-users in our study group was well integrated into the hearing world, concerning their schooling and post-graduate development. However their career perspectives are still not satisfying.

From 1-word to 2-words with cochlear implant and cued speech: a case study

This paper describes early language development in a deaf Spanish child fitted with a cochlear implant (CI) when she was 1;6 years old. The girl had been exposed to Cued Speech (CS) since that age. The main aim of the research was to identify potential areas of slow language development as well as the potential benefit of CI and CS. At the beginning of this research the child was 2;6 years (she had been using the CI for 12 months). Adult-child 30-minute sessions were videotaped every week for 1 year (13-24 months of CI use), and transcribed according to CHAT norms. Measures of phonemic inventory, intelligibility, lexicon, and grammar development were obtained. Part of the data were compared with data from two normally hearing (NH) children with the same mean length of utterance (MLU). In order to confirm trends observed during these 12 months of observation, an extra set of data was obtained in the next 3 months (25-27 months of CI use). Results in the initial 12 month period (13-24 months of CI use) showed irregular language development in the deaf child. The development of her phonemic inventory and lexicon progressed at a rate that was similar to, or faster than, that of NH children. However, the slow acquisition of articles and also the slow development of MLU suggested that the child might have problems with grammar. Data from the next 3 months (25-27 months of CI use) confirmed this trend. Results are discussed in relation to similar studies in other languages. Potential benefits of CS are also discussed.

Cochlear implantation in infants less than 12 months of age

OBJECTIVE

Infants are diagnosed with severe to profound hearing loss at an earlier age due to the advent of universal newborn hearing screening. This offers the opportunity to provide intervention in the form of cochlear implantation at an earlier age than was previously possible. The purpose of this investigation is to evaluate the risk of cochlear implant surgery in children less than 12 months of age.

DESIGN

Retrospective review of children who underwent cochlear implantation before 12 months of age.

SETTING

Patients were identified from a database of pediatric cochlear implant patients at a tertiary care center. All patients were diagnosed with severe to profound hearing loss by otoacoustic emission and auditory brainstem response. Follow-up ranged from 2 months to 5 years.

RESULTS

Fourteen of 15 patients had full insertions of the electrode hardware. Less than full insertion and post-operative CSF otorrhea occurred in one patient with severe cochlear abnormalities. There were no other perioperative surgical complications. The average speech detection threshold was 27.6 dB (20-45 dB) at approximately 1-3 months post-stimulation and 25 dB (15-30 dB) at approximately 5-7 months.

CONCLUSION

In our experience, we feel cochlear implantation is safe for infants as young as 6 months of age. The current standard at our institution is to implant by 7 months of age for prelingual deafness as opposed to waiting additional time until 12 months of age before the brain is presented with speech.

Effects of age at onset of deafness and electrical stimulation on the developing cochlear nucleus in cats

This study examined the effects of deafness and intracochlear electrical stimulation on the anatomy of the cochlear nucleus (CN) after a brief period of normal auditory development early in life. Kittens were deafened by systemic ototoxic drug injections either as neonates or starting at postnatal day 30. Total CN volume, individual CN subdivision volumes, and cross-sectional areas of spherical cell somata in the anteroventral CN (AVCN) were compared in neonatally deafened and 30-day deafened groups at 8 weeks of age and in young adults after approximately 6 months of electrical stimulation initiated at 8 weeks of age. Both neonatal and early acquired hearing loss resulted in a reduction in CN volume as compared to normal hearing cats. Comparison of 8- and 32-week old groups indicated that the CN continued to grow in both deafened groups despite the absence of auditory input. Preserving normal auditory input for 30 days resulted in a significant increase in both total CN volume and cross-sectional areas of spherical cell somata, as compared to neonatally deafened animals. Restoring auditory input in these developing animals by unilateral intracochlear electrical stimulation did not elicit any difference in CN volume between the two sides, but resulted in 7% larger spherical cell size on the stimulated side. Overall, the brief period of normal auditory development and subsequent electrical stimulation maintained CN volume at 80% of normal and spherical cell size at 86% of normal ipsilateral to the implant as compared to 67% and 74%, respectively, in the neonatally deafened group.

Impact of early hearing screening and treatment on language development and education level: evaluation of 6 years of universal newborn hearing screening (ALGO) in Flanders, Belgium

OBJECTIVES

Early intervention in hearing-impaired children may improve language outcomes and subsequent school and occupational performance. The objective of this study was to retrospectively analyze over 6 years the educational outcome and language development of a first cohort of children, detected by the Flemish universal newborn hearing screening (UNHS) program based on automated auditory brainstem response (AABR), with the oldest children being in primary school.

METHODS

We studied 229 hearing-impaired children from 1998 till 2003. The following variables were considered: the age during the school year 2005-2006, the degree of hearing loss, additional impairments including presence of intellectual disability, school placement and early intervention.

RESULTS

Analysis showed that 85.4% of the children with moderate, severe or profound hearing loss and no additional disability, older than 5.5 years, reach mainstream education. Further detailed description was provided for the outcomes of children with uni- and bilateral cochlear implants. Overall results stress that 46% of all children with a cochlear implant obtain mainstream education. Of all cochlear implant (CI) children above 5.5 years, without additional handicaps, 78.9% of children attend primary mainstream school. Data on language development show that up to 45% of the children with unilateral cochlear implant and no additional disabilities had normal to slight delay on language development. These data are fulfilling the goals stated by the JCIH and the American Academy of Pediatrics (AAP) in 2000. The role and impact of additional handicaps is discussed. The importance of early hearing loss identification and hearing therapy for appropriate language development is highlighted. Finally our preliminary results on children with bilateral cochlear implants without additional handicaps present an improved language development in comparison to unilateral CI-children.

CONCLUSION

A vast majority of the children detected by the UNHS program, with moderate, severe or profound hearing loss and no additional disability, older than 5.5 years, reach mainstream education. Additional disabilities have a major influence.

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.

From hearing screening to cochlear implantation: cochlear implants in children under 3 years of age

CONCLUSIONS

Universal hearing screening gives a deaf child earlier diagnosis and intervention with a better chance for successful management of hearing and speech development.

OBJECTIVES

Universal newborn hearing screening has a major impact on early identification of deafness in children. This study evaluated the outcome of cochlear implantation in screened and non-screened deaf children.

SUBJECTS AND METHODS

Group 1 comprised 9 deaf children diagnosed by screening; group 2 comprised 21 children diagnosed by traditional methods. The following parameters were evaluated: age at the time of diagnosis, age at the time of the first hearing aid fitting, age at the time of cochlear implantation. In children who had been using a cochlear implant for more than 2 years the results of audiological tests, category of auditory performance (CAP), and development and quality of speech were also evaluated.

RESULTS

Hearing screening significantly reduced the age at the time of diagnosis (6.9 months vs 15.4 months) as well as the age at the time of the first hearing aid fitting (9.3 months vs 17 months) and age at the time of cochlear implantation (26 months vs 32 months). Children from the screening program had better results in speech audiometry (95% discrimination vs 84%), monosyllabic tests (62% vs 34%), CAP (level 6 vs level 5), evaluation of spontaneous speech (level 6 vs level 5), and intelligibility of speech (level 5 vs level 3.5). According to the statistical evaluation (Fisher's test) the functional results did not show significant difference.

Executive function and language in deaf children

The relationship between language and executive function (EF) and their development in children have been the focus of recent debate and are of theoretical and clinical importance. Exploration of these functions in children with a peripheral hearing loss has the potential to be informative from both perspectives. This study compared the EF and language skills of 8- to 12-year-old children with cochlear implants (n = 22) and nonimplanted deaf children (n = 25) with those of age-matched hearing controls (n = 22). Implanted and nonimplanted deaf children performed below the level of hearing children on tests assessing oral receptive language, as well as on a number of EF tests, but no significant differences emerged between the implanted and nonimplanted deaf groups. Language ability was significantly positively associated with EF in both hearing and deaf children. Possible interpretations of these findings are suggested and the theoretical and clinical implications considered.

Pediatric cochlear implantation in Taiwan: long-term communication outcomes

OBJECTIVES/HYPOTHESIS

Cochlear implantation is an established method of auditory rehabilitation for severely and profoundly hearing impaired individuals. Although numerous studies have examined communication outcomes in pediatric cochlear implant (CI) recipients, data concerning the benefits of cochlear implantation in children who speak Mandarin Chinese are lacking. This study examined communication outcomes in 29 Mandarin-speaking children implanted at Chung Gung Memorial Hospital.

DESIGN

A prospective between-groups design was used to compare communication outcomes as a function of age at time of implantation.

METHODS

Children in the Younger group were implanted before 3 years of age, whereas children in the Older group were implanted after 3 years of age. Outcome measures assessed auditory thresholds, speech perception, speech intelligibility, receptive and expressive language skills, communication barriers, and communication mode. Correlation analysis was used to examine the relationship between communication outcome and age at implantation.

RESULTS

Children in the Younger group demonstrated a significant level of difference on Mandarin vowels, consonants, tones, and open-set speech perception compared with the children in the Older group. Between-group differences were also shown on receptive and expressive language skills. But, no significant differences were noted on speech intelligibility or in self-ratings of communication barriers. A larger proportion of children in the Younger group used oral communication and were educated in mainstream classrooms. Communication mode change of the Younger group reached a significant level after cochlear implant. Speech perception performance was negatively correlated with age at implantation as well as chronological age. Mandarin-speaking children can obtain substantial communication benefits from cochlear implantation, with earlier implantation yielding superior results.

Vocalizations of Infants with Hearing Loss Compared with Infants with Normal Hearing: Part II – Transition to Words

OBJECTIVE

By 24 mo of age, most typically developing infants with normal hearing successfully transition to the production of words that can be understood about 50% of the time. This study compares early phonological development in children with and without hearing loss to gain a clearer understanding of the effects of hearing loss in early-identified children. A secondary goal was to identify measures of early phonetic development that are predictors of later speech production outcomes.

DESIGN

The vocalizations and early words of 21 infants with normal hearing and 12 early-identified infants with hearing loss were followed longitudinally over a period of 14 mo (from 10 to 24 mo of age). Thirty-minute mother-child interaction samples were video recorded at 6- to 8-wk intervals in a laboratory playroom setting. Vocalizations produced at 16 and 24 mo were categorized according to communicative intent and recognizable words versus other types. Groups were compared on the structural complexity of words produced at 24 mo of age. Parent report measures of vocabulary development were collected from 10 to 30 mo of age, and Goldman-Fristoe Test of Articulation scores at 36 mo were used in regression analyses.

RESULTS

Both groups increased the purposeful use of voice between 16 and 24 mo of age. However, at 24 mo of age, the toddlers with hearing loss produced significantly fewer words that could be recognized by their mothers. Their samples were dominated by unintelligible communicative attempts at this age. In contrast, the samples from normal hearing children were dominated by words and phrases. At 24 mo of age, toddlers with normal hearing were more advanced than those with hearing loss on seven measures of the structural complexity of words. The children with normal hearing attempted more complex words and productions were more accurate than those of children with hearing loss. At 10 to 16 mo of age, the groups did not differ significantly on parent-report measures of receptive vocabulary. However, the hearing loss group was much slower to develop expressive vocabulary and demonstrated larger individual differences than the normal hearing group. Six children identified as atypical differed from all other children in vowel accuracy and complexity of word attempts. However, both atypical infants and typical infants with hearing loss were significantly less accurate than normal hearing infants in consonant and word production. Early measures of syllable production predicted unique variance in later speech production and vocabulary outcomes.

CONCLUSIONS

The transition from babble to words in infants with hearing loss appears to be delayed but parallel to that of infants with normal hearing. These delays appear to exert significant influences on expressive vocabulary development. Parents may appreciate knowing that some children with hearing loss may develop early vocabulary at a slower rate than children with normal hearing. Clinicians should monitor landmarks from babble onset through transitions to words. Indicators of atypical development were delayed and/or limited use of syllables with consonants, vowel errors and limited production of recognizable words.

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.

Will they catch up? The role of age at cochlear implantation in the spoken language development of children with severe to profound hearing loss

PURPOSE

The authors examined the benefits of younger cochlear implantation, longer cochlear implant use, and greater pre-implant aided hearing to spoken language at 3.5 and 4.5 years of age.

METHOD

Language samples were obtained at ages 3.5 and 4.5 years from 76 children who received an implant by their 3rd birthday. Hierarchical linear modeling was used to identify characteristics associated with spoken language outcomes at the 2 test ages. The Preschool Language Scale (I. L. Zimmerman, V. G. Steiner, & R. E. Pond, 1992) was used to compare the participants' skills with those of hearing age-mates at age 4.5 years.

RESULTS

Expected language scores increased with younger age at implant and lower pre-implant thresholds, even when compared at the same duration of implant use. Expected Preschool Language Scale scores of the children who received the implant at the youngest ages reached those of hearing age-mates by 4.5 years, but those children implanted after 24 months of age did not catch up with hearing peers.

CONCLUSION

Children who received a cochlear implant before a substantial delay in spoken language developed (i.e., between 12 and 16 months) were more likely to achieve age-appropriate spoken language. These results favor cochlear implantation before 24 months of age, especially for children with aided pure-tone average thresholds greater than 65 dB prior to surgery.

Importance of Age and Postimplantation Experience on Speech Perception Measures in Children With Sequential Bilateral Cochlear Implants

OBJECTIVES

Clinical trials in which children received bilateral cochlear implants in sequential operations were conducted to analyze the extent to which bilateral implantation offers benefits on a number of measures. The present investigation was particularly focused on measuring the effects of age at implantation and experience after activation of the second implant on speech perception performance.

STUDY DESIGN

Thirty children aged 3 to 13 years were recipients of 2 cochlear implants, received in sequential operations, a minimum of 6 months apart. All children received their first implant before 5 years of age and had acquired speech perception capabilities with the first device. They were divided into 3 age groups on the basis of age at time of second ear implantation: Group I, 3 to 5 years; Group II, 5.1 to 8 years; and Group III, 8.1 to 13 years. Speech perception measures in quiet included the Multisyllabic Lexical Neighborhood Test (MLNT) for Group I, the Lexical Neighborhood Test (LNT) for Groups II and III, and the Hearing In Noise Test for Children (HINT-C) sentences in quiet for Group III. Speech perception in noise was assessed using the Children's Realistic Intelligibility and Speech Perception (CRISP) test. Testing was performed preoperatively and again postactivation of the second implant at 3, 6, and 12 months (CRISP at 3 and 9 mo) in both the unilateral and bilateral conditions in a repeated-measures study design. Two-way repeated-measures analysis of variance was used to analyze statistical significance among device configurations and performance over time.

SETTING

US Multicenter.

RESULTS

Results for speech perception in quiet show that children implanted sequentially acquire open-set speech perception in the second ear relatively quickly (within 6 mo). However, children younger than 8 years do so more rapidly and to a higher level of speech perception ability at 12 months than older children (mean second ear MLNT/LNT scores at 12 months: Group I, 83.9%; range, 71-96%; Group II, 59.5%; range, 40-88%; Group III, 32%; range, 12-56%). The second-ear mean HINT-C score for Group III children remained far less than that of the first ear even after 12 months of device use (44 versus 89%; t, 6.48; p<0.001; critical value, 0.025). Speech intelligibility for spondees in noise was significantly better under bilateral conditions than with either ear alone when all children were analyzed as a single group and for Group III children. At the 9-month test interval, performance in the bilateral configuration was significantly better for all noise conditions (13.2% better for noise at first cochlear implant, 6.8% better for the noise front and noise at second cochlear implant conditions, t=2.32, p=0.024, critical level=0.05 for noise front; t=3.75, p<0.0001, critical level=0.05 for noise at first implant; t=2.73, p = 0.008, critical level=0.05 for noise at second implant side). The bilateral benefit in noise increased with time from 3 to 9 months after activation of the second implant. This bilateral advantage is greatest when noise is directed toward the first implanted ear, indicating that the head shadow effect is the most effective binaural mechanism. The bilateral condition produced small improvements in speech perception in quiet and for individual Group I and Group II patient results in noise that, in view of the relatively small number of subjects tested, do not reach statistical significance.

CONCLUSION

Sequential bilateral cochlear implantation in children of diverse ages has the potential to improve speech perception abilities in the second implanted ear and to provide access to the use of binaural mechanisms such as the head shadow effect. The improvement unfolds over time and continues to grow during the 6 to 12 months after activation of the second implant. Younger children in this study achieved higher open-set speech perception scores in the second ear, but older children still demonstrate bilateral benefit in noise. Determining the long-term impact and cost-effectiveness that results from such potential capabilities in bilaterally implanted children requires additional study with larger groups of subjects and more prolonged monitoring.

1-Year Postactivation Results for Sequentially Implanted Bilateral Cochlear Implant Users

OBJECTIVE

Evaluate speech recognition in quiet and in noise for a group of 12 children, all of whom underwent sequential bilateral cochlear implantation at various ages (range, 1 yr, 8 mo to 9 yr, 6 mo at time of second implant).

STUDY DESIGN

Retrospective.

SETTING

Outpatient cochlear implant clinic.

PATIENTS

Children who underwent sequential bilateral cochlear implantation.

INTERVENTION

Rehabilitative.

MAIN OUTCOME MEASURES

Speech recognition in quiet was evaluated for each ear separately using single-word speech recognition assessments (Multisyllabic Lexical Neighborhood Test and Early Speech Perception Test) via recorded presentation. Speech recognition in noise was assessed for each ear separately and in the bilateral condition by obtaining a spondee recognition threshold in the presence of speech-weighted noise presented at 45 dB hearing level. The primary outcome measure for speech recognition in noise assessment was the signal-to-noise ratio for 50% performance, which was calculated by determining the difference between the presentation level of the noise and the presentation level at which the speech recognition threshold was obtained. The results of these assessments were contrasted between children receiving their second cochlear implant before 4 years of age and children receiving their second cochlear implant after 4 years of age.

RESULTS

A statistically significant difference for speech recognition scores in quiet was obtained between the early-implanted ear and the late-implanted ears for children receiving their second cochlear implant after 4 years of age. There was not a statistically significant difference in speech recognition scores in quiet between the early-implanted and late-implanted ears of children receiving their second cochlear before 4 years of age. Both groups of children possessed better speech recognition scores in noise (statistically significant at an alpha = 0.05) in the bilateral condition relative to either unilateral condition. However, there was not a statistically significant relationship between speech recognition performance in noise and the duration of deafness of the later implanted ear.

CONCLUSION

Bilateral cochlear implantation allowed for better speech recognition in noise relative to unilateral performance for a group of 12 children who underwent sequential bilateral cochlear implantation at various ages. There was not a statistically significant relationship between speech recognition in noise benefit, which was defined as the difference in performance between the first implanted ear and the bilateral condition and the age at which the second implant was received. Children receiving bilateral cochlear implants younger than 4 years of age achieved better speech recognition in quiet performance for the later implanted ear as compared with children receiving their second cochlear implant after 4 year of age.

Neuropsychological correlates of vocabulary, reading, and working memory in deaf children with cochlear implants

The performance of deaf children with cochlear implants was assessed using measures standardized on hearing children. To investigate nonverbal cognitive and sensorimotor processes associated with postimplant variability, five selected sensorimotor and visuospatial subtests from A Developmental Neuropsychological Assessment (NEPSY) were compared with standardized vocabulary, reading, and digit span measures. Participants were 26 deaf children, ages 6-14 years, who received a cochlear implant between ages 1 and 6 years; duration of implant use ranged from 3 to 11 years. Results indicated significant correlations between standard scores on the Design Copying subtest of the NEPSY and standard scores on vocabulary comprehension, reading, and digit span measures. The results contribute to our understanding of the benefits of cochlear implantation and cognitive processes that may support postimplant language and academic functioning.