Language skills of profoundly deaf children who received cochlear implants under 12 months of age: a preliminary study

Production of nouns and adjectives of children with cochlear implants and of children with typical hearing

This analytical cross-sectional study aimed to investigate the production of nouns and adjectives in 62 children between the ages 5 and 7, with 31 children having Cochlear Implants (CIs) and 31 children having Typical Hearing (TH). The study compaired their performance in a picture naming test of nouns and adjectives. Poisson regression models were fitted to compare the responses of both groups of children, and intra-subject differences between responses to the noun and adjective naming tasks were also analyzed. The results showed that both groups of children produced the same number of non-responses of nouns and of adjectives and a higher number of correct productions of nouns than of adjectives. However, children with CIs produced more errors when naming adjectives than when naming nouns, while this difference is not observed in children with TH. The comparative analysis between both groups of children indicates that children with CIs produced a higher proportion of non-responses when naming nouns, but the same proportion as children with TH when naming adjectives. Children with CIs also produced fewer correct nouns and adjectives and more errors than children with TH. Vocabulary expansion and repair of production errors in children with CIs should be targeted by speech-language pathologists in intervention programs.

Language and academic outcomes of children with cochlear implants in an inclusive setting: Evidence from 18 years of data

OBJECTIVE

This study examined outcomes in core and pragmatic language, receptive vocabulary, and academic skills in children with cochlear implants (CIs) enrolled in an inclusive educational setting.

METHODS

Eighty-eight children with CIs were included in the analyses. Data was collected over an 18-year period, at six-month intervals for core language, vocabulary, and pragmatic skills and in kindergarten and second grade for academic skills. Kaplan-Meier analyses were used to estimate the median time to achieve age-appropriate scores.

RESULTS

Results indicated the median time to obtain age-appropriate skills for children with CIs enrolled in our program was less than three years for core language and pragmatic skills and less than two years for vocabulary. Over 90% of the sample had academic skills in the average range in both kindergarten and second grade.

DISCUSSION

This study shares outcomes of children with CIs who received consistent and intensive transdisciplinary intervention in an inclusive educational setting, revealing the trajectory required to obtain age-appropriate skills, when compared to normative data.

CONCLUSION

Results were favorable, indicating that children with CIs in an inclusive program, with intensive intervention and strong language and social models, can develop skills commensurate with typically developing peers across a variety of core skills.

Long Term Impact of Age at Implantation on Quality-of-Life Outcomes in Cochlear Implant Recipient Children

Cochlear implantation (CI) is used in management of children with bilateral severe to profound sensorineural hearing loss (SNHL). Recently, due to technological advancements, more and more infants and toddlers are undertaking the CI. The age at implantation may have an impact on CI outcomes. The primary aim of this study was to determine the long-term impact of 'age at implantation' on Health Related Quality of Life (HRQoL) outcome post-CI. In this prospective study at a tertiary care centre, we evaluated 50 CI recipient children from 2011 to 2018. Group A consisted of 35 (70%) children who received CI at less than or equal to 5 years of age and Group B with 15 (30%) children who underwent CI at more than 5 years of age. Following CI, all children received auditory-verbal therapy and thereafter we evaluated their long-term HRQoL outcomes at 5 years post-CI. Children were assessed by Nijmegen Cochlear Implant Questionnaire (NCIQ) and Children with cochlear implants: parental perspectives-questionnaire (CCIPPQ). There were significantly improved HRQoL outcomes (with an increase of 11.7% in mean NCIQ and 11.4% in mean CCIPPQ scores) at 5 years post-CI in CI recipients of age group '5 years or less' as compared to those who underwent CI at 'more than 5 years' age [P value < 0.05 for both the mean NCIQ scores and mean CCIPPQ scores respectively]. However, for children with 'more than 5 years' age at implantation, mean NCIQ and CCIPPQ scores were still more than 80% of maximum achievable NCIQ and CCIPPQ scores. In this study, CI recipient children who were implanted at less than or equal to 5 years of age were found to have significantly improved HRQoL outcomes at 5 years post-CI. Hence, it seems desirable to provide CI at an early age. However, even in children who received CI at more than 5 years of age, there was a substantial enhancement in HRQoL outcomes and CI was still effective in these children. Hence, knowledge of 'age at implantation' may provide reasonable assistance in predicting the HRQoL outcomes and optimal counseling of parents and families of CI candidates.

Dichotic listening deficits in children with hearing loss

PURPOSE

This correlational study compared dichotic listening among children with significant hearing loss to typically developing children and children clinically assessed for auditory processing disorder.

METHOD

Recorded versions of two dichotic tests were delivered under earphones or in the sound field for children using amplification. Individual ear scores and interaural asymmetry were compared to normative data. Matched deficit patterns from both tests were identified, ranked for severity of deficit, and compared across groups. Relationships between dichotic scores and factors related to amplification were investigated in the children with hearing loss.

RESULTS

Dichotic scores were significantly poorer among children with hearing loss without the large interaural asymmetries seen in children assessed clinically for auditory processing problems. Device type and age of implantation had no effect on scores; non-dominant ear scores on the digits test were significantly correlated to age of device use in the left ear and duration of device use in the right ear. Non-dominant ear scores with digits were also significantly correlated with bilateral word recognition.

CONCLUSIONS

Poor dichotic perception in children with significant hearing losses may be related to the use of recorded test materials, immature skills in attention and working memory, or other factors that contribute to development of vocabulary and language. These weaknesses may interfere with successful mainstream educational placement in these children. Assessment of dichotic performance in this population could lead to deficit-specific interventions that may improve outcomes and enhance educational opportunities for children with hearing loss.

Longitudinal Changes in BDNF and MMP-9 Protein Plasma Levels in Children after Cochlear Implantation

Congenitally deaf children who undergo cochlear implantation before 1 year of age develop their auditory skills faster than children who are implanted later. In this longitudinal study, a cohort of 59 implanted children were divided into two subgroups according to their ages at implantation-below or above 1 year old-and the plasma levels of matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and pro-BDNF were measured at 0, 8, and 18 months after cochlear implant activation, while auditory development was simultaneously evaluated using the LittlEARs Questionnaire (LEAQ). A control group consisted of 49 age-matched healthy children. We identified statistically higher BDNF levels at 0 months and at the 18-month follow-ups in the younger subgroup compared to the older one and lower LEAQ scores at 0 months in the younger subgroup. Between the subgroups, there were significant differences in the changes in BDNF levels from 0 to 8 months and in LEAQ scores from 0 to 18 months. The MMP-9 levels significantly decreased from 0 to 18 months and from 0 to 8 months in both subgroups and from 8 to 18 months only in the older one. For all measured protein concentrations, significant differences were identified between the older study subgroup and the age-matched control group.

Effect of telepractice on pediatric cochlear implant users and provider vowel space: A preliminary report

Clear speaking styles are goal-oriented modifications in which talkers adapt acoustic-phonetic characteristics of speech to compensate for communication challenges. Do children with hearing loss and a clinical provider modify speech characteristics during telepractice to adjust for remote communication? The study examined the effect of telepractice (tele-) on vowel production in seven (mean age 4:11 years, SD 1:2 years) children with cochlear implants (CIs) and a provider. The first (F1) and second (F2) formant frequencies of /i/, /ɑ/, and /u/ vowels were measured in child and provider speech during one in-person and one tele-speech-language intervention, order counterbalanced. Child and provider vowel space areas (VSA) were calculated. The results demonstrated an increase in F2 formant frequency for /i/ vowel in child and provider speech and an increase in F1 formant frequency for /ɑ/ vowel in the provider speech during tele- compared to in-person intervention. An expansion of VSA was found in child and provider speech in tele- compared to in-person intervention. In children, the earlier age of CI activation was associated with larger VSA in both tele- and in-person intervention. The results suggest that the children and the provider adjust vowel articulation in response to remote communication during telepractice.

Trends in Timing and Provision of Pediatric Cochlear Implant Care During COVID‐19

Objectives

To identify trends in timing of pediatric cochlear implant (CI) care during COVID-19.

Study Design

Retrospective cohort.

Setting

Tertiary care center.

Methods

Patients under 18 years of age who underwent CI between 1/1/2016 and 2/29/2020 were included in the pre-COVID-19 group, and patients implanted between 3/1/2020 and 12/31/2021 comprised the COVID-19 group. Revision and sequential surgeries were excluded. Time intervals between care milestones including severe-to-profound hearing loss diagnosis, initial CI candidacy evaluation, and surgery were compared among groups, as were the number and type of postoperative visits.

Results

A total of 98 patients met criteria; 70 were implanted pre-COVID-19 and 28 during COVID-19. A significant increase in the interval between CI candidacy evaluation and surgery was seen among patients with prelingual deafness during COVID-19 compared with pre-COVID-19 (µ = 47.3 weeks, 95% confidence interval [CI]: 34.8-59.9 vs µ = 20.5 weeks, 95% CI: 13.1-27.9; p < .001). Patients in the COVID-19 group attended fewer in-person rehabilitation visits in the 12 months after surgery (µ = 14.9 visits, 95% CI: 9.7-20.1 vs µ = 20.9, 95% CI: 18.1-23.7; p = .04). Average age at implantation in the COVID-19 group was 5.7 years (95% CI: 4.0-7.5) versus 3.7 years in the pre-COVID-19 group (95% CI: 2.9-4.6; p = .05). The time interval between hearing loss confirmation and CI surgery was on average 99.7 weeks for patients implanted during COVID-19 (95% CI: 48.8-150) versus 54.2 weeks for patients implanted pre-COVID (95% CI: 39.6-68.8), which was not a statistically significant difference (p = .1).

Conclusion

During the COVID-19 pandemic patients with prelingual deafness experienced delays in care relative to patients implanted before the pandemic.

Younger Age at Cochlear Implant Activation Results in Improved Auditory Skill Development for Children With Congenital Deafness

PURPOSE

The U.S. Food and Drug Administration indications for cochlear implantation in children is currently 9 months of age and older for children with bilateral profound sensorineural hearing loss (SNHL). Studies have shown that earlier activation of a cochlear implant (CI) can lead to better spoken language outcomes. As auditory skills are a precursor to the development of spoken language, this study was developed to investigate the influence of age at CI activation on auditory skill acquisition in young children. A secondary aim was to describe the auditory skills of children implanted prior to 9 months of age as compared to children with older ages of activation.

METHOD

Functional Listening Index (FLI) scores obtained during routine clinical visits were reviewed for 78 pediatric CI recipients with congenital bilateral profound hearing loss who were activated before 2 years of age. A linear mixed-effects model assessed the effect of age at CI activation on cumulative FLI scores over time.

RESULTS

There was a significant interaction between age at activation and chronological age at the time of evaluation, indicating that children with earlier access to sound achieved a greater number of auditory skills than those with later CI activations when measured at the same chronological age. Children activated before the age of 9 months approximated scores expected of children with typical hearing, whereas children activated between 9 and 24 months of age did not.

CONCLUSIONS

Younger age at CI activation is associated with increased auditory skills over time. Children who undergo cochlear implantation and CI activation before 9 months achieve more auditory skills by 4 years of age than children who are activated at later ages. These data suggest that reducing the approved age at cochlear implantation for children with congenital bilateral profound SNHL may support optimal auditory skill acquisition.

Assessment of Behavioral Problems in Children Pre- and Post-Cochlear Implant: An Egyptian Study

OBJECTIVE

The present study aimed to detect the behavioral problems pre- and post-cochlear implantation in comparison to normal hearing group to be able to manage these problems to get more benefit from using cochlear implants.

METHODS

A case-control study included 53 children was done. They were divided into 2 groups, the control group included 28 healthy volunteers with normal hearing and the case group included 25 children with severe to profound hearing loss, fitted for cochlear implantation. The Arabic Child Behavior Checklist (CBCL) was used to detect different behavioral problems in both groups. Case group children were followed up and reassessed again by CBCL 3 months later after cochlear implantation.

RESULTS

There were highly significant differences regarding total scores of internalizing and externalizing domains of empirically based CBCL between the control group and the case group after cochlear implants (p=0.001). There were non-significant differences in children within case group (pre- and post-cochlear implantation) regarding emotional and behavioral problems on both empirically based and Diagnostic and Statistical Manual of Mental Disorders-based CBCL.

CONCLUSION

For better results, it is necessary to include a specialist of psychosomatic medicine in the cochlear rehabilitation teamwork.

A Retrospective Evaluation to Assess Reliability of Electrophysiological Methods for Diagnosis of Hearing Loss in Infants

Background: An electrophysiological investigation with auditory brainstem response (ABR), round window electrocochleography (RW-ECoG), and electrical-ABR (E-ABR) was performed in children with suspected hearing loss with the purpose of early diagnosis and treatment. The effectiveness of the electrophysiological measures as diagnostic tools was assessed in this study. Methods: In this retrospective case series with chart review, 790 children below 3 years of age with suspected profound hearing loss were tested with impedance audiometry and underwent electrophysiological investigation (ABR, RW-ECoG, and E-ABR). All implanted cases underwent pure-tone audiometry (PTA) of the non-implanted ear at least 5 years after surgery for a long-term assessment of the reliability of the protocol. Results: Two hundred and fourteen children showed bilateral severe-to-profound hearing loss. In 56 children with either ABR thresholds between 70 and 90 dB nHL or no response, RW-ECoG showed thresholds below 70 dB nHL. In the 21 infants with bilateral profound sensorineural hearing loss receiving a unilateral cochlear implant, no statistically significant differences were found in auditory thresholds in the non-implanted ear between electrophysiological measures and PTA at the last follow-up (p > 0.05). Eight implanted children showed residual hearing below 2000 Hz worse than 100 dB nHL and 2 children showed pantonal residual hearing worse than 100 dB nHL (p > 0.05). Conclusion: The audiological evaluation of infants with a comprehensive protocol is highly reliable. RW-ECoG provided a better definition of hearing thresholds, while E-ABR added useful information in cases of auditory nerve deficiency.

Relationship between parental stress and attitude towards cochlear implantation outcomes in children in an Indian context

PURPOSE

The study was aimed to investigate the relationship between parental stress and attitude of parents towards the outcomes of cochlear implantation in an Indian scenario.

METHODS

A total of 59 parents of children with cochlear implantation participated in the study. The outcomes of cochlear implant was measured using Parental attitudes of various aspects of cochlear implantation questionnaire and parental stress was measured using parental stress scale. The questionnaires were circulated to participants and data was collected in the form of e-survey.

RESULTS

The present study showed that the parental stress level was similar among mothers and fathers. Further, the parental attitude towards communication abilities of children and education were positively correlated with the duration of cochlear implantation. Finally, a significant positive correlation was found between the parental stress and the parental attitude towards communication abilities of children and social skills.

CONCLUSION

The present study showed a positive relationship between parental stress and parental attitude towards the outcomes of cochlear implantation for aspects of communication abilities and social skills.

Differences in picture naming between children with cochlear implants and children with typical hearing

Increase in the auditory abilities of children with cochlear implants (CIs) has led to an improvement in naming tasks, although divergent results are still being reported; this strongly suggests that further studies are needed. The study aims to compare the responses in a picture-naming activity between the complete population of children aged 5 to 7 with cochlear implants in Catalonia -Spain- (N = 31), without developmental problems, and a matched sample of 31 children with typical hearing. A picture-naming task was used to assess their lexical naming abilities. The results show that children with CIs provide more non-responses, they produce fewer words correctly, they require a longer reaction time and they commit more picture-naming errors than children with typical hearing. The auditory age does significantly affect the results, but not the type of implant. In spite of the hearing gain achieved with the cochlear implant and the listening experience progressively achieved in distinct contexts, further explicit work on lexical naming in speech-therapy intervention is clearly required.

Early pediatric Cochlear implantation: An update

The criteria and candidacy for pediatric cochlear implantation (CI) has significantly transformed over the past few decades and continues to evolve with technological advancements, and recognition of benefit in more diverse populations. Prolonged auditory deprivation among patients with profound sensorineural hearing loss has been shown to cause widespread degeneration in the central auditory system. Thus, there is increasing evidence advocating for earlier implantation within a critical neuroplastic window. However, there is a lack of consensus on this optimal age of implantation. Historically, there were concerns regarding surgical feasibility and safety, anesthesia risk, and logistical considerations in very young infants <12 months. Recent literature has investigated surgical safety and anesthesia risk as well speech and language outcomes with early implantation, resulting in the long-awaited reduction in approved age by the FDA (<9 months for certain devices). This article reviews logistical considerations, surgical safety, anesthesia risk, and language developmental outcomes associated with early CI (<12 months).

Early pediatric Cochlear implantation: An update

The criteria and candidacy for pediatric cochlear implantation (CI) has significantly transformed over the past few decades and continues to evolve with technological advancements, and recognition of benefit in more diverse populations. Prolonged auditory deprivation among patients with profound sensorineural hearing loss has been shown to cause widespread degeneration in the central auditory system. Thus, there is increasing evidence advocating for earlier implantation within a critical neuroplastic window. However, there is a lack of consensus on this optimal age of implantation. Historically, there were concerns regarding surgical feasibility and safety, anesthesia risk, and logistical considerations in very young infants <12 months. Recent literature has investigated surgical safety and anesthesia risk as well speech and language outcomes with early implantation, resulting in the long-awaited reduction in approved age by the FDA (<9 months for certain devices). This article reviews logistical considerations, surgical safety, anesthesia risk, and language developmental outcomes associated with early CI (<12 months).

[Impact of CI use and CI fitting on speech production in very early cochlear-implanted infants]

BACKGROUND

Children's age at implantation is an important factor for their outcome in auditory and language skills with a cochlear implant (CI). CI use and frequency of CI fitting may also influence speech performance. Purpose of this study was to evaluate CI use and CI fitting of very early implanted infants and its potential influence on age-related speech production performance.

METHODS

Data of 34 bilaterally cochlea-implanted infants (age at CI in months: M = 8,8; SD = 1,7) were included. During the third year of life speech production performance was evaluated and related to datalogging-based CI use and number of CI fitting sessions.

RESULTS

About half of the cohort achieved speech production level within the normal range of hearing peers. Daily time of CI use was approximately 8 h. Analysis of listening environment showed that infants were exposed most of the time to quiet environment and least amount of time to speech in noise. Daily time of CI use seems to be a significant predictor of speech production, speech-exposition particularly predicts word production. Number of daily disconnection between CI-processor and implant as well as the monthly number of CI fitting sessions were not correlated with speech production.

CONCLUSION

Very early cochlear implanted infants may achieve age-appropriate speech production performance in the third year of life. Time of daily CI use in the study cohort is comparable to results of other studies. Time of daily CI use and exposure to speech seem to be important factors for early speech production. These findings should be integrated in pre- and postoperative parent counselling.

JT, Waltzman SB. Cochlear Implantation in Infants: Evidence of Safety

The aim of this study was to investigate surgical, anesthetic, and device-related complications associated with cochlear implantation (CI) in children younger than 1 year of age. This was a multicenter, retrospective chart review of all children with severe-to-profound sensorineural hearing loss who underwent cochlear implantation with a Cochlear Nucleus Implant System before 1 year of age. Endpoints included perioperative course, major and minor surgical, anesthetic and device-related complications, and 30-day readmission rates. One hundred thirty-six infants (242 ears) met criteria. The mean age at implantation was 9.4 months (standard deviation 1.8). Six-month follow-up was reported in all patients. There were no major anesthetic or device-related complications. Adverse events were reported in 34 of implanted ears (14%; 7 major, 27 minor). Sixteen adverse events occurred ≤30 days of surgery, and 18 occurred >30 days of surgery. The 30-day readmission rate was 1.5%. The rate of adverse events did not correlate with preexisting medical comorbidities or duration under anesthesia. There was no significant difference detected in complication rate for patients younger than 9 months of age versus those 9 to 11 months of age. This study demonstrates the safety of CI surgery in infants and supports reducing the indication for cochlear implantation to younger than 1 year of age for children with bilateral, profound sensorineural hearing loss obtaining a Cochlear Nucleus Implant System.

Receptive and Expressive Language in Hindi Speaking Children with Postcochlear Implantation at 6-Month Intervals

Introduction  Individual variability in the language outcomes of children with cochlear implantation (CI) is a major concern. In CI rehabilitation, there is lack of a protocol regarding uniform post-CI language assessment interval duration, which can ensure better understanding of the trajectory of language growth as well as optimize language outcomes by providing feedback in fine tuning the language intervention program.

Objective  To evaluate the receptive and expressive language in Hindi speaking children with up to 2 years of CI experience using revised receptive-expressive emergent language test-3ed. (REELT-3) at 6 months intervals and to compare it with that of children with normal hearing (NH).

Methods  The present study included 192 children divided in 2 groups, 96 children with CI (15.8 ± 6.7 months), and 96 age-matched children with NH (22.3 ± 7.9 months). A cross-sectional, prospective study design was used to measure the language ability score (LAS) at an interval of 6 months from the time of implantation (TIA), which is 0 to 6 months, 7 to 12 months, 13 to 18 months, and 19 to 24 months of CI usage.

Results  The two-way analysis of variance revealed that the LAS after 18 months of CI usage was similar to (F (3, 92) = 8.63, p  = 0.19, ηp2 = 0.028) that of the children with NH. However, other demographic factors, for instance, gender (F (3, 92) = 1.73, p  = 0.505, ηp2 = 0.002), parent's education, (F (3, 92) = 2.05, p  = 0.937, ηp2 = 0.031), and financial background (F (3, 92) = 2.49, p  = 0.351, ηp2 = 0.076) had no major impact on language.

Conclusion  Eighteen months of CI usage duration can potentially stimulate receptive and expressive language up to age-matched children with NH. A protocol of periodic assessment of language, at least of 6 months, may be developed to optimize language outcomes.

Morphosyntactic profile of Egyptian children after 5 years of using unilateral cochlear implants

OBJECTIVE

to assess the morphosyntactic aspect of language in Egyptian children after 5 years of using unilateral cochlear implants and studying the factors that affect their progress: the chronological age, the age of implantation, the gender, and the duration of using cochlear implant. Also, to assess which of the subcategories of the morphosyntax are affected to help in designing a suitable rehabilitation program.

MATERIALS AND METHODS

36 Egyptian children using unilateral cochlear implants regularly were enrolled in this cross-sectional study. During the assessment, the chronological age of all children was ranged from 6 years, 7 months to 11 years, 9 months, the duration of using cochlear implants of all children was at least 5 years. The morphosyntactic aspect of language as a part of the REAL scale (Receptive Expressive Arabic Language Scale) was applied by expert Phoniatricians.

RESULTS

Morphosyntactic score was affected negatively by the chronological age, on the other hand, it was not affected by the age of implantation, the gender, or the duration of using cochlear implant.

CONCLUSION

After 5 years of regular rehabilitation of Egyptian children using unilateral cochlear implants, the morphosyntactic profile can be described as still low compared to normal children. These children have developed many items in morphosyntactic aspects like possessiveness, derivative adjectives, and passive tense but still have a defect especially in male plural formation, past tense, adjectives, and irregular plural formation.

Hearing and speech benefits of cochlear implantation in children: A review of the literature

Cochlear implantation is a safe and reliable treatment for children with severe to profound hearing loss. The primary benefit of these medical devices in children is the acquisition of hearing, which promotes development of spoken language. The present paper reviews published literature demonstrating predictive effects of a number of factors on acquisition of hearing development and speech recognition. Of the many variables that contribute to an individual child's development after implantation, age at implantation, the presence of medical comorbidities, social determinants of health, and the provision of bilateral versus unilateral hearing are those that can vary widely and have consistently shown clear impacts. Specifically, age of implantation is crucial to reduce effects of deafness on the developing auditory system and capture the remarkable plasticity of early development. Language development after cochlear implantation requires therapy emphasizing hearing and oral communication, education, and other support which can be influenced by known social determinants of health; specifically, outcomes in children decline with reductions in socioeconomic status and levels of parental education. Medical co-morbidities also slow rates of progress after cochlear implantation. On the other hand, benefits of implantation increase in children who are provided with access to hearing from both ears. In sum, cochlear implants promote development of hearing in children and the best outcomes are achieved by providing early access to sound in both ears. These benefits can be limited by known social determinants of health which restrict access to needed support and medical comorbidities which add further complexity in care and outcome.

Effects of Age at Cochlear Implantation on Auditory Outcomes in Cochlear Implant Recipient Children

Cochlear implantation (CI) is used for rehabilitation of children with bilateral severe to profound sensorineural hearing loss. Recently, treatment of such children has been influenced by diagnostic technological advances. Infants and toddlers are now increasingly included for CI. The primary aim of this study was to determine the effects of 'age at CI' on CI outcome. The primary aim of this study was to determine the effects of 'age at CI' on CI outcome. In this prospective study at a tertiary care centre, we evaluated 50 cochlear implanted children from October 2011 to March 2013. The case group consists of 15 (30%) children who underwent CI at more than 5 years of age and control group consisted of 35 (70%) children who underwent CI at less than or equal to 5 years age. All patients received auditory and speech rehabilitation and we evaluated their auditory perception outcomes 1 year post CI, the children were assessed by categories of auditory performance (CAP) and meaningful auditory integration scale (MAIS) tests. There were significantly improved mean auditory perception outcomes (increase of 12.29% in CAP, and 14.05% in MAIS scores) at 1 year post CI in CI recipients of age group '5 years or less' in comparison to those who underwent CI at 'more than 5 years of age'. However, children of 'more than 5 years' age at CI, mean CAP and MAIS scores were still more than 80% of maximum achievable CAP and MAIS scores. In this study, CI recipient children who were implanted at less than or equal to 5 years of age were found to have significantly improved auditory perception outcome at 1 year post CI. Hence, it appears preferable to provide CI early. However, even in children who underwent CI at more than 5 years of age, there was substantial improvement in auditory perception outcomes and CI was still helpful in these children. Hence, knowledge of 'age at CI' can provide reasonable help in predicting the auditory perception outcome and optimal counselling of families of CI candidates.

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.

Discrimination and identification of lexical tones and consonants in Mandarin-speaking children using cochlear implants

Mandarin-speaking adults using cochlear implants (CI) experience more difficulties in perceiving lexical tones than consonants. This problem may result from the fact that CIs provide relatively sufficient temporal envelope information for consonant perception in quiet environments, but do not convey the fine spectro-temporal information considered to be necessary for accurate pitch perception. Another possibility is that Mandarin speakers with post-lingual hearing loss have developed language-specific use of these acoustic cues, impeding lexical tone processing under CI conditions. To investigate this latter hypothesis, syllable discrimination and word identification abilities for Mandarin consonants (place and manner) and lexical-tone contrasts (tones 1 vs 3 and 1 vs 2) were measured in 15 Mandarin-speaking children using CIs and age-matched children with normal hearing (NH). In the discrimination task, only children using CIs exhibited significantly lower scores for consonant place contrasts compared to other contrasts, including lexical tones. In the word identification task, children using CIs showed lower performance for all contrasts compared to children with NH, but they both showed specific difficulties with tone 1 vs 2 contrasts. This study suggests that Mandarin-speaking children using CIs are able to discriminate and identify lexical tones and, perhaps more surprisingly, have more difficulties when discriminating consonants.

Glendonald Auditory Screening Procedure (GASP): clinical markers of the development of auditory recognition and comprehension abilities in children using cochlear implants

PURPOSE

To verify the influence of the age of implantation in the development of closed-set auditory recognition and auditory comprehension abilities in children using unilateral cochlear implants (CI), comparing distinct groups and determining clinical markers.

METHODS

Participants were 180 children operated and activated until 36 months of age and who used a CI for at least 60 months. Abilities of auditory recognition in closed-set and auditory comprehension were analyzed through the GASP Tests 5 and 6. The influence of age of implantation was investigated with three groups of children: implanted before 18 months (G1), between 19 and 24 months (G2) and between 25 and 36 months of age (G3).

RESULTS

There was no statistically significant difference when comparing the three groups. Children progressively developed auditory abilities, presenting auditory recognition ability together at approximately 41±4 months of CI use and auditory comprehension at 53±4 months.

CONCLUSION

There was no correlation between hearing performance and age of implantation for children implanted before 36 months of age. For the abilities of auditory recognition and comprehension, the clinical marker was 41±4 and 53±4 months of auditory age, respectively. Therefore, it is expected that, around 60 months of CI use, children implanted during the sensitive period can understand speech without the aid of orofacial reading, reaching the most complex hearing abilities.

Validation of the Egyptian Arabic Assessment of Auditory Skills development using children with Cochlear Implants

INTRODUCTION

Audition is the gateway to spoken language, and infants' early accomplishments in acquiring the sound structure of their native language lays a critical ground work for subsequent learning. The development of pre-lingual auditory perceptual skills for cochlear implanted children is crucial for initial development of oral language.

OBJECTIVE

The aims of the present study were to validate the Egyptian Arabic Assessment of Auditory Skills, and to track the development of auditory skills in Egyptian children fitted with CI during the first three years post implantation.

METHODS

The study included 90 Arabic Egyptian children attending the phoniatric unit, Kasr El Aini hospital. Their chronological age ranged from 36 to 72 months. The study lasted for 18 months from July 2015 to January 2017. The children were divided into six groups according to their cochlear age i.e., amount of implant experience. An Arabic assessment chart of auditory skills was tailored that included six auditory skills' domains; detection, identification, short term auditory memory, supra-segmental discrimination, segmental discrimination and linguistic auditory processing. This chart was then used to develop an assessment tool which was then applied to all the study participants. All children had bilateral Sensorineural Hearing Loss (SNHL) since birth. None of the participants had prior Cochlear Implant (CI), but all had tried conventional hearing aids. All participants were implanted unilateral, with CI devices. All met selection criteria applied in the Egyptian national insurance committee for cochlear implantation.

RESULTS

All auditory skills domains improved with cochlear age. There was significant improvement between 1-6 and 7-12 months in the scores of the Detection (DET) domain. There was significant difference between 1-6 and 7-12 months, 7-12 and 13-18 months, 19-24 and 25-30 months in the scores of the Identification (IDENT) domain. Regarding the Short Term Auditory Memory (STAM) domain scores and the Supra-segmental Discrimination (SSD) domain scores there was significant difference between all the groups. Regarding the Segmental Discrimination (SGD) domain scores, there was significant difference between group 1-6 and 7-12 months, 7-12 and 13-18 months, 19-24 and 25-30 months, 25-30 and 31-36 months. Regarding the Linguistic Auditory Processing (LAP) domain, there was significant difference between group 1-6 and 7-12 months, 7-12 and 13-18 months, 25-30 and 31-36 months.

CONCLUSIONS

Children fitted with Cochlear Implants (CIs) appeared to show improvement in acquisition of auditory skills over a period of three years that followed a hierarchy of development dependent on the cochlear age.

Language and hearing outcomes of preterm infants

Multiple factors including degree of prematurity, neonatal morbidities, illness severity, hearing status, gender, language environment in the neonatal intensive care unit and in the home, maternal education level, social and environmental status of the family, and access to early intervention all contribute to the language outcomes of extremely preterm infants with and without hearing loss. Early screening, early diagnosis, and early intervention services by 6 months of age are necessary to optimize the language outcomes of preterm infants with permanent hearing loss. There is increasing evidence of the potential for improved language skills with increasing age of extreme preterm infants and infants with hearing loss.

Newborn hearing screening in Queensland 2009-2011: Comparison of hearing screening and diagnostic audiological assessment between term and preterm infants

AIM

This study compares rates and timing of newborn hearing screening outcomes, audiological assessment and hearing loss diagnosis between infants of different gestational age groups. Early identification and management of sensorineural hearing loss (SNHL), ideally by 3-6 months of age, facilitates speech and language optimisation. Literature stratifying hearing screening and diagnostic audiology assessment by gestational age groups is lacking.

METHODS

Subjects were infants with recorded gestational ages receiving newborn hearing screening in Queensland between 2009 and 2011. Data were provided through the Queensland Healthy Hearing database. Infants were analysed in <34 weeks, 34-36⁺⁶ weeks, 37-38⁺⁶ weeks and ≥39 weeks gestational age groups.

RESULTS

Infants (175 911) were eligible for analysis, 7.9% being preterm. Per 1000 infants analysed, bilateral SNHL of >40 dB occurred in 2.4 for <34, 1.4 for 34-36⁺⁶ , 0.7 for 37-38⁺⁶ and 0.7 for ≥39 weeks gestation. Diagnoses attributable to newborn hearing screening direct referral were 93.1% for bilateral >40 dB SNHL and 88.2% for other hearing loss. Relative to term, preterm infants had a higher incidence of direct and targeted surveillance referrals, audiology assessment and hearing loss diagnosis. Preterm infants were screened later after birth.

CONCLUSIONS

Specific hearing screening and diagnosis characteristics differed between preterm infants <34 and 34-36⁺⁶ weeks gestation, and term infants. Consideration of unique gestational age strata characteristics supports care individualisation. Preterm infants represent a diagnostic challenge, with higher rates of bilateral >40 dB SNHL than term but correspondingly higher false positive results on screening, justifying vigilant monitoring. Focused research into specific risk factors in preterm infants is warranted.

Pediatric Cochlear Implantation: Why Do Children Receive Implants Late?

OBJECTIVES

Early cochlear implantation has been widely promoted for children who derive inadequate benefit from conventional acoustic amplification. Universal newborn hearing screening has led to earlier identification and intervention, including cochlear implantation in much of the world. The purpose of this study was to examine age and time to cochlear implantation and to understand the factors that affected late cochlear implantation in children who received cochlear implants.

DESIGN

In this population-based study, data were examined for all children who underwent cochlear implant surgery in one region of Canada from 2002 to 2013. Clinical characteristics were collected prospectively as part of a larger project examining outcomes from newborn hearing screening. For this study, audiologic details including age and severity of hearing loss at diagnosis, age at cochlear implant candidacy, and age at cochlear implantation were documented. Additional detailed medical chart information was extracted to identify the factors associated with late implantation for children who received cochlear implants more than 12 months after confirmation of hearing loss.

RESULTS

The median age of diagnosis of permanent hearing loss for 187 children was 12.6 (interquartile range: 5.5, 21.7) months, and the age of cochlear implantation over the 12-year period was highly variable with a median age of 36.2 (interquartile range: 21.4, 71.3) months. A total of 118 (63.1%) received their first implant more than 12 months after confirmation of hearing loss. Detailed analysis of clinical profiles for these 118 children revealed that late implantation could be accounted for primarily by progressive hearing loss (52.5%), complex medical conditions (16.9%), family indecision (9.3%), geographical location (5.9%), and other miscellaneous known (6.8%) and unknown factors (8.5%).

CONCLUSIONS

This study confirms that despite the trend toward earlier implantation, a substantial number of children can be expected to receive their first cochlear implant well beyond their first birthday because they do not meet audiologic criteria of severe to profound hearing loss for cochlear implantation at the time of identification of permanent hearing loss. This study underscores the importance of carefully monitoring all children with permanent hearing loss to ensure that optimal intervention including cochlear implantation occurs in a timely manner.

Paediatric Cochlear Implantation in Patients with Waardenburg Syndrome

OBJECTIVE

To analyse the benefit of cochlear implantation in young deaf children with Waardenburg syndrome (WS) compared to a reference group of young deaf children without additional disabilities.

METHOD

A retrospective study was conducted on children with WS who underwent cochlear implantation at the age of 2 years or younger. The post-operative results for speech perception (phonetically balanced standard Dutch consonant-vocal-consonant word lists) and language comprehension (the Reynell Developmental Language Scales, RDLS), expressed as a language quotient (LQ), were compared between the WS group and the reference group by using multiple linear regression analysis.

RESULTS

A total of 14 children were diagnosed with WS, and 6 of them had additional disabilities. The WS children were implanted at a mean age of 1.6 years and the 48 children of the reference group at a mean age of 1.3 years. The WS children had a mean phoneme score of 80% and a mean LQ of 0.74 at 3 years post-implantation, and these results were comparable to those of the reference group. Only the factor additional disabilities had a significant negative influence on auditory perception and language comprehension.

CONCLUSIONS

Children with WS performed similarly to the reference group in the present study, and these outcomes are in line with the previous literature. Although good counselling about additional disabilities concomitant to the syndrome is relevant, cochlear implantation is a good rehabilitation method for children with WS.

Factors Affecting Speech Discrimination in Children with Cochlear Implants: Evidence from Early-Implanted Infants

BACKGROUND

To learn words and acquire language, children must be able to discriminate and correctly perceive phonemes. Although there has been much research on the general language outcomes of children with cochlear implants (CIs), little is known about the development of speech perception with regard to specific speech processes, such as speech discrimination.

PURPOSE

The purpose of this study was to investigate the development of speech discrimination in infants with CIs and identify factors that might correlate with speech discrimination skills.

RESEARCH DESIGN

Using a Hybrid Visual Habituation procedure, we tested infants with CIs on their ability to discriminate the vowel contrast /i/-/u/. We also gathered demographic and audiological information about each infant.

STUDY SAMPLE

Children who had received CIs before 2 yr of age served as participants. We tested the children at two post cochlear implantation intervals: 2-4 weeks post CI stimulation (N = 17) and 6-9 mo post CI stimulation (N = 10).

DATA COLLECTION AND ANALYSIS

The infants' mean looking times during the novel versus old trials of the experiment were measured. A linear regression model was used to evaluate the relationship between the normalized looking time difference and the following variables: chronological age, age at CI stimulation, gender, communication mode, and best unaided pure-tone average.

RESULTS

We found that the best unaided pure-tone average predicted speech discrimination at the early interval. In contrast to some previous speech perception studies that included children implanted before 3 yr of age, age at CI stimulation did not predict speech discrimination performance.

CONCLUSIONS

The results suggest that residual acoustic hearing before implantation might facilitate speech discrimination during the early period post cochlear implantation; with more hearing experience, communication mode might have a greater influence on the ability to discriminate speech. This and other studies on age at cochlear implantation suggest that earlier implantation might not have as large an effect on speech perception as it does on other language skills.

Current trends in outcome studies for children with hearing loss and the need to establish a comprehensive framework of measuring outcomes in children with hearing loss in China

Since the 1970s, outcome studies for children with hearing loss expanded from focusing on assessing auditory awareness and speech perception skills to evaluating language and speech development. Since the early 2000s, the multi-center large scale research systematically studied outcomes in the areas of auditory awareness, speech-perception, language development, speech development, educational achievements, cognitive development, and psychosocial development. These studies advocated the establishment of baseline and regular follow-up evaluations with a comprehensive framework centered on language development. Recent research interests also include understanding the vast differences in outcomes for children with hearing loss, understanding the relationships between neurocognitive development and language acquisition in children with hearing loss, and using outcome studies to guide evidence-based clinical practice. After the establishment of standardized Mandarin language assessments, outcomes research in Mainland China has the potential to expand beyond auditory awareness and speech perception studies.

A Systematic Review to Define the Speech and Language Benefit of Early (<12 Months) Pediatric Cochlear Implantation

Objective: This review aimed to evaluate the additional benefit of pediatric cochlear implantation before 12 months of age considering improved speech and language development and auditory performance. Materials and Methods: We conducted a search in PubMed, EMBASE and CINAHL databases and included studies comparing groups with different ages at implantation and assessing speech perception and speech production, receptive language and/or auditory performance. We included studies with a high directness of evidence (DoE). Results: We retrieved 3,360 articles. Ten studies with a high DoE were included. Four articles with medium DoE were discussed in addition. Six studies compared infants implanted before 12 months with children implanted between 12 and 24 months. Follow-up ranged from 6 months to 9 years. Cochlear implantation before the age of 2 years is beneficial according to one speech perception score (phonetically balanced kindergarten combined with consonant-nucleus-consonant) but not on Glendonald auditory screening procedure scores. Implantation before 12 months resulted in better speech production (diagnostic evaluation of articulation and phonology and infant-toddler meaningful auditory integration scale), auditory performance (Categories of Auditory Performance-II score) and receptive language scores (2 out of 5; Preschool Language Scale combined with oral and written language skills and Peabody Picture Vocabulary Test). Conclusions: The current best evidence lacks level 1 evidence studies and consists mainly of cohort studies with a moderate to high risk of bias. Included studies showed consistent evidence that cochlear implantation should be performed early in life, but evidence is inconsistent on all speech and language outcome measures regarding the additional benefit of implantation before the age of 12 months. Long-term follow-up studies are necessary to provide insight on additional benefits of early pediatric cochlear implantation.

Semantic and syntactic reading comprehension strategies used by deaf children with early and late cochlear implantation

Deaf students have traditionally exhibited reading comprehension difficulties. In recent years, these comprehension problems have been partially offset through cochlear implantation (CI), and the subsequent improvement in spoken language skills. However, the use of cochlear implants has not managed to fully bridge the gap in language and reading between normally hearing (NH) and deaf children, as its efficacy depends on variables such as the age at implant. This study compared the reading comprehension of sentences in 19 children who received a cochlear implant before 24 months of age (early-CI) and 19 who received it after 24 months (late-CI) with a control group of 19 NH children. The task involved completing sentences in which the last word had been omitted. To complete each sentence children had to choose a word from among several alternatives that included one syntactic and two semantic foils in addition to the target word. The results showed that deaf children with late-CI performed this task significantly worse than NH children, while those with early-CI exhibited no significant differences with NH children, except under more demanding processing conditions (long sentences with infrequent target words). Further, the error analysis revealed a preference of deaf students with early-CI for selecting the syntactic foil over a semantic one, which suggests that they draw upon syntactic cues during sentence processing in the same way as NH children do. In contrast, deaf children with late-CI do not appear to use a syntactic strategy, but neither a semantic strategy based on the use of key words, as the literature suggests. Rather, the numerous errors of both kinds that the late-CI group made seem to indicate an inconsistent and erratic response when faced with a lack of comprehension. These findings are discussed in relation to differences in receptive vocabulary and short-term memory and their implications for sentence reading comprehension.

Complications in a series of 4400 paediatric cochlear implantation

OBJECTIVES

The purpose of this study is to retrospectively review the complications of paediatric patients undergoing cochlear implantation at four major Iranian cochlear implant centres.

METHODS

A retrospective analysis was performed of all patients who underwent primary cochlear implantation from January 1991 to December 2013. The patients were reviewed for demographic information, and complications including cerebrospinal fluid leak, meningitis, facial palsy, and wound infection.

RESULTS

4400 records were reviewed. Fifty-four patients were lost to follow-up; therefore, 4346 records were analysed. The most common aetiology of hearing loss was non-syndromic genetic sensori-neural hearing loss (69%). Other less common aetiologies of hearing loss included TORCH (Toxoplasmosis, Other infections, Rubella, Cytomegalovirus, Herpes) (11%), syndromic hearing loss (7%), ototoxicity (5%), and autoimmune inner-ear disease (4%). The most common major complications were CSF leak (0.4%), skin necrosis (0.2%), meningitis (0.1%), facial paralysis (0.07%) and massive haemorrhage (0.05).

CONCLUSION

Cochlear implantation continues to be reliable and safe in experienced hands, with a very low percentage of severe complications.

Factors influencing speech and language outcomes of children with early identified severe/profound hearing loss: Clinician-identified facilitators and barriers

PURPOSE

Early identification of severe/profound childhood hearing loss (HL) gives these children access to hearing devices and early intervention to facilitate improved speech and language outcomes. Predicting which infants will go on to achieve such outcomes remains difficult. This study describes clinician identified malleable and non-malleable factors that may influence speech and language outcomes for children with severe/profound HL.

METHOD

Semi-structured interviews were conducted with six experienced auditory verbal clinicians. A collective case study design was implemented. The interviews were transcribed and coded into themes using constant comparative analysis.

RESULT

Clinicians identified that, for children with severe/profound HL, early identification, early amplification and commencing auditory-verbal intervention under 6 months of age may facilitate child progress. Possible barriers were living in rural/remote areas, the clinicians' lack of experience and confidence in providing intervention for infants under age 6-months and belonging to a family with a culturally and linguistically diverse (CALD) background.

CONCLUSION

The results indicate that multiple factors need to be considered by clinicians working with children with HL and their families to determine how each child functions within their own environment and personal contexts, consistent with the International Classification of Functioning, Disability and Health (ICF) framework. Such an approach is likely to empower clinicians to carefully balance potential barriers to, and facilitators of, optimal speech and language outcomes for all children with HL.

Audiological outcomes of cochlear implantation in Waardenburg Syndrome

INTRODUCTION

 The most relevant clinical symptom in Waardenburg syndrome is profound bilateral sensorioneural hearing loss.

AIM

 To characterize and describe hearing outcomes after cochlear implantation in patients with Waardenburg syndrome to improve preoperative expectations.

METHOD

 This was an observational and retrospective study of a series of cases. Children who were diagnosed with Waardenburg syndrome and who received a multichannel cochlear implant between March 1999 and July 2012 were included in the study. Intraoperative neural response telemetry, hearing evaluation, speech perception, and speech production data before and after surgery were assessed.

RESULTS

 During this period, 806 patients received a cochlear implant and 10 of these (1.2%) were diagnosed with Waardenburg syndrome. Eight of the children received a Nucleus 24(®) implant and 1 child and 1 adult received a DigiSonic SP implant. The mean age at implantation was 44 months among the children. The average duration of use of a cochlear implant at the time of the study was 43 months. Intraoperative neural responses were present in all cases. Patients who could use the speech processor effectively had a pure tone average of 31 dB in free-field conditions. In addition, the MUSS and MAIS questionnaires revealed improvements in speech perception and production. Four patients did not have a good outcome, which might have been associated with ineffective use of the speech processor.

CONCLUSION

 Despite the heterogeneity of the group, patients with Waardenburg syndrome who received cochlear implants were found to have hearing thresholds that allowed access to speech sounds. However, patients who received early intervention and rehabilitation showed better evolution of auditory perception.

Morpho-syntactic reading comprehension in children with early and late cochlear implants

This study explores morpho-syntactic reading comprehension in 19 Spanish children who received a cochlear implant (CI) before 24 months of age (early CI [e-CI]) and 19 Spanish children who received a CI after 24 months (late CI [l-CI]). They all were in primary school and were compared to a hearing control (HC) group of 19 children. Tests of perceptual reasoning, working memory, receptive vocabulary, and morpho-syntactic comprehension were used in the assessment. It was observed that while children with l-CI showed a delay, those with e-CI reached a level close to that which was obtained by their control peers in morpho-syntactic comprehension. Thus, results confirm a positive effect of early implantation on morpho-syntactic reading comprehension. Inflectional morphology and simple sentence comprehension were noted to be better in the e-CI group than in the l-CI group. The most important factor in distinguishing between the HC and l-CI groups or the e-CI and l-CI groups was verbal inflectional morphology.

Picture naming and verbal fluency in children with cochlear implants

PURPOSE

In the present study, the authors examined lexical naming in children with cochlear implants (CIs). The goal was to determine whether children with CIs have deficits in lexical access and organization as revealed through reaction time in picture-naming and verbal fluency (VF) experiments.

METHOD

Children with CIs (n = 20, ages 7-10) were compared with 20 children with normal hearing (NH) matched for age and nonverbal IQ. Lexical abilities were examined using two naming tasks: a timed picture-naming task and a phonological and semantic VF naming task. Picture naming taps into lexical access capabilities and the VF task elucidates lexical organization.

RESULTS

No group differences were found between children with CIs and children with NH on the timed picture-naming task. Children with CIs generated significantly fewer words than the children with NH on the VF tasks. Larger group differences were found for the phonological VF task compared with the semantic VF task.

CONCLUSIONS

Limited early linguistic and auditory experiences may affect lexical representations and organization (lexical-semantic connections) in school-age children with hearing loss who use CIs. Further analyses and studies should continue to examine these underlying linguistic deficits. The present results suggest a need to emphasize not only increasing the size of children's vocabularies during therapy, but also expanding and increasing the semantic and phonological richness of their lexical representations.

Developmental and cross-modal plasticity in deafness: evidence from the P1 and N1 event related potentials in cochlear implanted children

Cortical development is dependent on extrinsic stimulation. As such, sensory deprivation, as in congenital deafness, can dramatically alter functional connectivity and growth in the auditory system. Cochlear implants ameliorate deprivation-induced delays in maturation by directly stimulating the central nervous system, and thereby restoring auditory input. The scenario in which hearing is lost due to deafness and then reestablished via a cochlear implant provides a window into the development of the central auditory system. Converging evidence from electrophysiologic and brain imaging studies of deaf animals and children fitted with cochlear implants has allowed us to elucidate the details of the time course for auditory cortical maturation under conditions of deprivation. Here, we review how the P1 cortical auditory evoked potential (CAEP) provides useful insight into sensitive period cut-offs for development of the primary auditory cortex in deaf children fitted with cochlear implants. Additionally, we present new data on similar sensitive period dynamics in higher-order auditory cortices, as measured by the N1 CAEP in cochlear implant recipients. Furthermore, cortical re-organization, secondary to sensory deprivation, may take the form of compensatory cross-modal plasticity. We provide new case-study evidence that cross-modal re-organization, in which intact sensory modalities (i.e., vision and somatosensation) recruit cortical regions associated with deficient sensory modalities (i.e., auditory) in cochlear implanted children may influence their behavioral outcomes with the implant. Improvements in our understanding of developmental neuroplasticity in the auditory system should lead to harnessing central auditory plasticity for superior clinical technique.

Transient Hearing Loss Within a Critical Period Causes Persistent Changes to Cellular Properties in Adult Auditory Cortex

Sensory deprivation can induce profound changes to central processing during developmental critical periods (CPs), and the recovery of normal function is maximal if the sensory input is restored during these epochs. Therefore, we asked whether mild and transient hearing loss (HL) during discrete CPs could induce changes to cortical cellular physiology. Electrical and inhibitory synaptic properties were obtained from auditory cortex pyramidal neurons using whole-cell recordings after bilateral earplug insertion or following earplug removal. Varying the age of HL onset revealed brief CPs of vulnerability for membrane and firing properties, as well as, inhibitory synaptic currents. These CPs closed 1 week after ear canal opening on postnatal day (P) 18. To examine whether the cellular properties could recover from HL, earplugs were removed prior to (P17) or after (P23), the closure of these CPs. The earlier age of hearing restoration led to greater recovery of cellular function, but firing rate remained disrupted. When earplugs were removed after the closure of these CPs, several changes persisted into adulthood. Therefore, long-lasting cellular deficits that emerge from transient deprivation during a CP may contribute to delayed acquisition of auditory skills in children who experience temporary HL.

Expressive vocabulary, morphology, syntax and narrative skills in profoundly deaf children after early cochlear implantation

Practical experience and research reveal generic spoken language benefits after cochlear implantation. However, systematic research on specific language domains and error analyses are required to probe sub-skills. Moreover, the effect of predictive factors on distinct language domains is unknown. In this study, outcomes of 70 school-aged children with cochlear implants were compared with hearing peers. Approximately half of the children with cochlear implants achieved age-adequate language levels. Results did not reveal systematic strong or weak language domains. Error analyses showed difficulties with morphological and syntactic rules and inefficient narrative skills. Children without additional disabilities who received early intervention were raised with one spoken language, and used a second cochlear implant or contralateral hearing aid were more likely to present good language skills.

Spoken language benefits of extending cochlear implant candidacy below 12 months of age

OBJECTIVE

To test the hypothesis that cochlear implantation surgery before 12 months of age yields better spoken language results than surgery between 12 and 18 months of age.

STUDY DESIGN

Language testing administered to children at 4.5 years of age (± 2 mo).

SETTING

Schools, speech-language therapy offices, and cochlear implant (CI) centers in the United States and Canada.

PARTICIPANTS

Sixty-nine children who received a cochlear implant between ages 6 and 18 months of age. All children were learning to communicate via listening and spoken language in English-speaking families.

MAIN OUTCOME MEASURE

Standard scores on receptive vocabulary, expressive, and receptive language (includes grammar).

RESULTS

Children with CI surgery at 6 to 11 months (n = 27) achieved higher scores on all measures as compared with those with surgery at 12 to 18 months (n = 42). Regression analysis revealed a linear relationship between age of implantation and language outcomes throughout the 6- to 18-month surgery-age range.

CONCLUSION

For children in intervention programs emphasizing listening and spoken language, cochlear implantation before 12 months of age seems to provide a significant advantage for spoken language achievement observed at 4.5 years of age.

Cochlear implantation in children with cochlear nerve deficiency: a report of nine cases

OBJECTIVE

Cochlear implantation for children with cochlear nerve deficiency remains controversial, as the presence of the cochlear nerve has been central to the success of cochlear implantation. This study sought to investigate whether there is any benefit from cochlear implantation for children with cochlear nerve deficiency.

METHODS

Nine children with cochlear nerve deficiency and bilateral prelingual profound sensorineural hearing loss were included in this study. Inner ear and internal auditory canal structures were evaluated using magnetic resonance imaging and temporal bone computed tomography scans. Meaningful auditory integration scales, categories of auditory performance scores, speech intelligibility ratings and pure tone average threshold with cochlear implantation were measured for evaluation of hearing and speech performance.

RESULTS

Only four (44.4%) children had a significant improvement in pure tone average threshold with the cochlear implant device (77.5 dBHL, 45 dBHL, 51.3 dBHL and 68.8 dBHL). No child achieved sufficient speech intelligibility or perception ability during a follow-up of at least one year after surgery.

CONCLUSIONS

The decision to perform cochlear implantation in children with cochlear nerve deficiency must be undertaken with caution as it has limited effectiveness and uncertain cost-benefit.

Influence of DFNB1 status on expressive language in deaf children with cochlear implants

OBJECTIVE

The objective of this study was to compare the language growth of children with connexin-related deafness (DFNB1) who received cochlear implants versus the language growth of implanted children with non-DFNB1 deafness.

STUDY DESIGN

A prospective longitudinal observational study and analysis.

SETTING

Two tertiary referral centers.

PATIENTS

There were 37 children with severe-to-profound hearing loss who received cochlear implants before the age of 5 years.

INTERVENTIONS

A standardized language measure, the section for expressive language of the Reynell Developmental Language Scale was used to assess expressive language skills at 2 times postimplantation (14 and 57 mo postimplantation). Molecular screening for DFNB1 gene variants.

MAIN OUTCOME MEASURES

Language quotient (LQ) scores (i.e., age-equivalent score obtained on the Reynell Developmental Language Scale divided by the child's chronological age), results of genotyping.

RESULTS

The mean language age at the second time interval (mean ± standard deviation, 51.8 ± 13 mo) was greater than at the first testing session (mean ± standard deviation, 19 ± 8 mo, p < 0.001, Wilcoxon signed rank test). When divided by genotype, DFNB1 children exhibited a higher LQ and less variability in scores than non-DFNB1 children at the second testing interval (Wilcoxon sign rank test, p = 0.0034). A regression analysis (linear-fit by least squares) conducted on 26 children with preimplantation audiometric data showed that DFNB1 status was the independent variable with greater predictive effect on LQ at the second testing interval, followed by age at implantation (R2 = 0.35, p = 0.0479).

CONCLUSION

Deaf children who received cochlear implants before the age of 5 years and use oral communication show substantial improvement in language abilities. In this study, DFNB1 children who use cochlear implants show greater gains in expressive language than non-DFNB1 children, independent of residual hearing, age at implantation, and duration of implant use.

Word learning in deaf children with cochlear implants: effects of early auditory experience

Word-learning skills were tested in normal-hearing 12- to 40-month-olds and in deaf 22- to 40-month-olds 12 to 18 months after cochlear implantation. Using the Intermodal Preferential Looking Paradigm (IPLP), children were tested for their ability to learn two novel-word/novel-object pairings. Normal-hearing children demonstrated learning on this task at approximately 18 months of age and older. For deaf children, performance on this task was significantly correlated with early auditory experience: Children whose cochlear implants were switched on by 14 months of age or who had relatively more hearing before implantation demonstrated learning in this task, but later implanted profoundly deaf children did not. Performance on this task also correlated with later measures of vocabulary size. Taken together, these findings suggest that early auditory experience facilitates word learning and that the IPLP may be useful for identifying children who may be at high risk for poor vocabulary development.