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

Perceptual development of nasal consonants in children with normal hearing and in children who use cochlear implants

PURPOSE

This study was conducted to determine whether the perceptions of nasal consonants in children with normal hearing and children with cochlear implants were predicted by the discontinuity hypothesis. Methods Four groups participated: 8 adults, 8 children with normal hearing (ages 5-7 years), 8 children with normal hearing (ages 3.5-4 years), and 5 children with cochlear implants (ages 5-7 years). Stimuli were 128 nasal consonant + vowel (/m/ /n/ + /i/ /æ/ /u/ //) syllables produced by a male adult. Each syllable production was edited into 4 segment types: (a) 50-ms murmur, (b) 25-ms murmur + 25-ms transition, (c) 50-ms transition, and (d) full syllable.

RESULTS

Developmental effects were observed across listener groups. The children performed better in the 25-ms murmur + 25-ms transition condition, which suggests that they benefit from an integrated perceptual cue. The children wearing cochlear implants performed poorer than children with normal hearing on all segments.

CONCLUSIONS

Developmental differences in perception of nasal consonants were evident. Children wearing cochlear implants showed weaker integration and perception abilities compared to younger children with normal hearing. As predicted by the discontinuity hypothesis, the segment with the spectral discontinuity provided the strongest perceptual cues to place of articulation of nasals in children with normal hearing.

Young cochlear implant users' auditory development as measured and monitored by the LittlEARS® Auditory Questionnaire: a Turkish experience

OBJECTIVE

This study aims to assess the usefulness of the LittlEARS(®) Auditory Questionnaire (LEAQ) in determining the audiological development of Turkish children who have received a cochlear implant.

METHODS

20 children received a cochlear implant before their 3rd birthday. Each child's progress was evaluated with the LittlEARS(®) Auditory Questionnaire at first device fitting and then at 3-month intervals for 2 years. Scores were compared with the age-related norms established by hearing children.

RESULTS

All children showed a significant increase in LittlEARS(®) Auditory Questionnaire scores over time. Nearly all children showed a growth in auditory skills similar to that of hearing children. Children without additional needs showed more development than did children with additional needs.

CONCLUSIONS

The LittlEARS(®) Auditory Questionnaire is useful for monitoring the audiological development of young children with a cochlear implant. Confirmation that a cochlear implant user is achieving typical auditory milestones serves to boost parental morale during a child's pre-verbal stage when parents may be anxious about their child's ability to talk. The questionnaire could also be useful as an early warning system. Poor scores likely indicate that something is impeding the child's development. This should prompt professionals to try to identify the impediment, whether technical, medical, social or educational and, possibly, eliminate/mitigate its effects while the child is still in his/her critical development stages.

Análise dos níveis de pressão sonora emitidos por brinquedos infantis

OBJETIVO: Verificar os níveis de pressão sonora emitidos por brinquedos infantis sem certificação. MÉTODOS: Estudo transversal com brinquedos sonoros ofertados em lojas de comércio popular, chamado de setor informal. Foram considerados brinquedos eletrônicos, mecânicos e musicais. A mensuração de cada produto foi realizada por um engenheiro acústico, em cabine isolada acusticamente, por meio de um decibelímetro. Para obter os parâmetros sonoros de intensidade e frequência, os brinquedos foram acionados a uma distância de 10 e 50cm da orelha do pesquisador. A intensidade foi verificada em nível de pressão sonora em decibéis dB(A) e a frequência, em hertz (Hz). RESULTADOS: Foram avaliados 48 brinquedos. Nas medidas a 10cm da orelha, foi registrada uma faixa de pressão sonora de 102±10 dB(A) e, a 50cm, a média foi de 94±8 dB(A), com p<0,05. A maioria dos brinquedos apresentou nível de pressão sonora acima de 85dB(A). A frequência variou de 413 a 6.635Hz, sendo que 56,3% dos brinquedos emitiram som com frequência superior a 2.000Hz. CONCLUSÕES: Constatou-se que a maioria dos brinquedos emitiu sons com elevado nível de pressão.

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.

Enduring advantages of early cochlear implantation for spoken language development

PURPOSE

In this article, the authors sought to determine whether the precise age of implantation (AOI) remains an important predictor of spoken language outcomes in later childhood for those who received a cochlear implant (CI) between 12 and 38 months of age. Relative advantages of receiving a bilateral CI after age 4.5 years, better pre-CI-aided hearing, and longer CI experience were also examined.

METHOD

Sixty children participated in a prospective longitudinal study of outcomes at 4.5 and 10.5 years of age. Twenty-nine children received a sequential second CI. Test scores were compared with normative samples of hearing age mates, and predictors of outcomes were identified.

RESULTS

Standard scores on language tests at 10.5 years of age remained significantly correlated with age of first cochlear implantation. Scores were not associated with receipt of a second, sequentially acquired CI. Significantly higher scores were achieved for vocabulary as compared with overall language, a finding not evident when the children were tested at younger ages.

CONCLUSION

Age-appropriate spoken language skills continued to be more likely with younger AOI, even after an average of 8.6 years of additional CI use. Receipt of a second implant between ages 4 and 10 years and longer duration of device use did not provide significant added benefit.

A case study assessing the auditory and speech development of four children implanted with cochlear implants by the chronological age of 12 months

Children with severe hearing loss most likely receive the greatest benefit from a cochlear implant (CI) when implanted at less than 2 years of age. Children with a hearing loss may also benefit greater from binaural sensory stimulation. Four children who received their first CI under 12 months of age were included in this study. Effects on auditory development were determined using the German LittlEARS Auditory Questionnaire, closed- and open-set monosyllabic word tests, aided free-field, the Mainzer and Göttinger speech discrimination tests, Monosyllabic-Trochee-Polysyllabic (MTP), and Listening Progress Profile (LiP). Speech production and grammar development were evaluated using a German language speech development test (SETK), reception of grammar test (TROG-D) and active vocabulary test (AWST-R). The data showed that children implanted under 12 months of age reached open-set monosyllabic word discrimination at an age of 24 months. LiP results improved over time, and children recognized 100% of words in the MTP test after 12 months. All children performed as well as or better than their hearing peers in speech production and grammar development. SETK showed that the speech development of these children was in general age appropriate. The data suggests that early hearing loss intervention benefits speech and language development and supports the trend towards early cochlear implantation. Furthermore, the data emphasizes the potential benefits associated with bilateral implantation.

Spatial acuity in 2-to-3-year-old children with normal acoustic hearing, unilateral cochlear implants, and bilateral cochlear implants

OBJECTIVES

: To measure spatial acuity on a right-left discrimination task in 2-to-3-year-old children who use a unilateral cochlear implant (UCI) or bilateral cochlear implants (BICIs); to test the hypothesis that BICI users perform significantly better when they use two CIs than when using a single CI, and that they perform better than the children in the UCI group; to determine how well children with CIs perform compared with children who have normal acoustic hearing (NH); to determine the effect of intensity roving on spatial acuity.

DESIGN

: Three groups of children between 26 and 36 months of age participated in this study: 8 children with NH (mean age: 30.9 months), 12 children who use a UCI (mean age: 31.9 months), and 27 children who use BICIs (mean age: 30.7 months). Testing was conducted in a large sound-treated booth with loudspeakers positioned in a horizontal arc with a radius of 1.2 m. The observer-based psychophysical procedure was used to measure the children's ability to identify the hemifield containing the sound source (right versus left). Two methods were used for quantifying spatial acuity, an adaptive-tracking method and a fixed-angle method. In Experiment 1 an adaptive tracking algorithm was used to vary source angle, and the minimum audible angle (MAA), the smallest angle at which right-left discrimination performance is better than chance, was estimated. All three groups participated in Experiment 1. In Experiment 2 source angles were fixed at ±50 degrees, and performance was evaluated by computing the number of SDs above chance. Children in the UCI and BICI groups participated in Experiment 2.

RESULTS

: In Experiment 1, when stimulus intensity was roved by 8 dB, MAA thresholds were 3.3 degrees to 30.2 degrees (mean = 14.5 degrees) and 5.7 degrees to 69.6 degrees (mean = 30.9 degrees) in the NH group and in the BICI group, respectively. When the intensity level was fixed for the BICI group, performance did not improve. Within the BICI group, 5 out of 27 children obtained MAA thresholds within one SD of their peers who have NH; all five had >12 months of bilateral listening experience. In Experiment 2, BICIs provided some advantages when the intensity level was fixed. First, the BICI group outperformed the UCI group. Second, children in the BICI group who repeated the task with their 1st CI alone had statistically significantly better performance when using both devices. In addition, when intensity roving was introduced, a larger percentage of children who had 12 or more months of BICI experience continued to perform above chance than children who had <12 months of BICI experience. Taken together, the results suggest that children with BICIs have spatial acuity that is better than when using their first CI alone and than that of their peers who use UCIs. In addition, longer durations of BICI use tend to result in better performance, although this cannot be generalized to all participants.

CONCLUSION

: This report is consistent with a growing body of evidence that spatial-hearing skills can emerge in young children who use BICIs. The observation that these skills are not concomitantly emerging in age- and experience-matched children who use UCIs suggests that BICIs provide cues that are necessary for these spatial-hearing skills that UCIs do not provide.

Rethinking education of deaf children in Zimbabwe: challenges and opportunities for teacher education

The study explores the communication challenges faced by teacher trainees in teaching deaf learners and the opportunities that they present. A critical disabilities study approach within the qualitative paradigm was employed to collect interview data from 14 trainee teachers (6 were men and 8 women) and 5 of their specialist mentors (all of them were women) at 3 special schools in Zimbabwe. The trainees were aged 28-45. Data were analyzed using theme identification methods. Results showed that all the mentors and trainees without deaf assistants tended to teach using spoken language and even though they had no prior experience with them, they were suspicious of the use of deaf assistants, whom they saw as synonymous with sign language. Scepticism about using sign language was based on the idea that it was inadequate, would interfere with spoken language development, and would not enable learners to be included in a nondeaf world. It was also established that most of the mentors and trainees with deaf assistants used spoken language to teach, although this tended to be in combination with signs. Based on these challenges, opportunities to develop the education of deaf learners are discussed and recommendations made.

Listen up: children with early identified hearing loss achieve age-appropriate speech/language outcomes by 3 years-of-age

OBJECTIVES

Age-appropriate speech/language outcomes for children with early identified hearing loss are a possibility but not a certainty. Identification of children most likely to achieve optimal outcomes is complicated by the heterogeneity of the children involved in outcome research, who present with a range of malleable (e.g. age of identification and cochlear implantation, type of intervention, communication mode) and non-malleable (e.g. degree of hearing loss) factors. This study considered whether a homogenous cohort of early identified children (≤ 12 months), with all severities of hearing loss and no other concomitant diagnoses could not only significantly outperform a similarly homogenous cohort of children who were later identified (>12 months to <5 years), but also achieve and maintain age-appropriate speech/language outcomes by 3, 4 and 5 years of age.

METHODS

A mixed prospective/retrospective comparative study of a homogenous cohort of 45 early identified (≤ 12 months) and 49 late identified (> 12 months to < 5 years) children with hearing loss was conducted. The children all attended the same oral auditory-verbal early intervention programme. Speech/language assessments standardized on typically developing hearing children were conducted at 3, 4 and 5 years of age.

RESULTS

The early identified children significantly outperformed the late identified at all ages and for all severities of HL. By 3 years of age, 93% of all early identified participants scored within normal limits (WNL) for speech; 90% were WNL for understanding vocabulary; and 95% were WNL for receptive and expressive language. Progress was maintained and improved so that by 5 years of age, 96% were WNL for speech, with 100% WNL for language.

CONCLUSIONS

This study found that most children with all severities of hearing loss and no other concomitant diagnosed condition, who were early diagnosed; received amplification by 3 months; enrolled into AV intervention by 6 months and received a cochlear implant by 18 months if required, were able to "keep up with" rather than "catch up to" their typically hearing peers by 3 years of age on measures of speech and language, including children with profound hearing loss. By 5 years, all children achieved typical language development and 96% typical speech.

Effects of simultaneous speech and sign on infants' attention to spoken language

OBJECTIVES

To examine the hypothesis that infants receiving a degraded auditory signal have more difficulty segmenting words from fluent speech if familiarized with the words presented in both speech and sign compared to familiarization with the words presented in speech only.

STUDY DESIGN

Experiment utilizing an infant-controlled visual preference procedure.

METHODS

Twenty 8.5-month-old normal-hearing infants completed testing. Infants were familiarized with repetitions of words in either the speech + sign (n = 10) or the speech only (n = 10) condition. Infants were then presented with four six-sentence passages using an infant-controlled visual preference procedure. Every sentence in two of the passages contained the words presented in the familiarization phase, whereas none of the sentences in the other two passages contained familiar words.

RESULTS

Infants exposed to the speech + sign condition looked at familiar word passages for 15.3 seconds and at nonfamiliar word passages for 15.6 seconds, t (9) = -0.130, p = .45. Infants exposed to the speech only condition looked at familiar word passages for 20.9 seconds and to nonfamiliar word passages for 15.9 seconds. This difference was statistically significant, t (9) = 2.076, p = .03.

CONCLUSIONS

Infants' ability to segment words from degraded speech is negatively affected when these words are initially presented in simultaneous speech and sign. The current study suggests that a decreased ability to segment words from fluent speech may contribute towards the poorer performance of pediatric cochlear implant recipients in total communication settings on a wide range of spoken language outcome measures.

Speech discrimination after early exposure to pulsed-noise or speech

Early experience of structured inputs and complex sound features generate lasting changes in tonotopy and receptive field properties of primary auditory cortex (A1). In this study we tested whether these changes are severe enough to alter neural representations and behavioral discrimination of speech. We exposed two groups of rat pups during the critical period of auditory development to pulsed-noise or speech. Both groups of rats were trained to discriminate speech sounds when they were young adults, and anesthetized neural responses were recorded from A1. The representation of speech in A1 and behavioral discrimination of speech remained robust to altered spectral and temporal characteristics of A1 neurons after pulsed-noise exposure. Exposure to passive speech during early development provided no added advantage in speech sound processing. Speech training increased A1 neuronal firing rate for speech stimuli in naïve rats, but did not increase responses in rats that experienced early exposure to pulsed-noise or speech. Our results suggest that speech sound processing is resistant to changes in simple neural response properties caused by manipulating early acoustic environment.

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.

Nonverbal cognitive development in children with cochlear implants: relationship between the Mullen Scales of Early Learning and later performance on the Leiter International Performance Scales-Revised

Methodologically, longitudinal assessment of cognitive development in young children has proven difficult because few measures span infancy through school age. This matter is further complicated when the child presents with a sensory deficit such as hearing loss. Few measures are validated in this population, and children who are evaluated for cochlear implantation are often reevaluated annually. The authors sought to evaluate the predictive validity of subscales of the Mullen Scales of Early Learning (MSEL) on Leiter International Performance Scales-Revised (LIPS-R) Full-Scale IQ scores. To further elucidate the relationship of these two measures, comparisons were also made with the Vineland Adaptive Behavior Scale-Second Edition (VABS), which provides a measure of adaptive functioning across the life span. Participants included 35 children (14 female, 21 male) who were evaluated both as part of the precandidacy process for cochlear implantation using the MSEL and VABS and following implantation with the LIPS-R and VABS. Hierarchical linear regression revealed that the MSEL Visual Reception subdomain score significantly predicted 52% of the variance in LIPS-R Full-Scale IQ scores at follow-up, F(1, 34) = 35.80, p < .0001, R (2) = .52, β = .72. This result suggests that the Visual Reception subscale offers predictive validity of later LIPS-R Full-Scale IQ scores. The VABS was also significantly correlated with cognitive variables at each time point.

Phonological awareness of Cantonese-speaking pre-school children with cochlear implants

The study investigated the phonological awareness abilities of Cantonese-speaking pre-schoolers with cochlear implants. Participants were 15 Cantonese-speaking children with cochlear implants (CIs) aged 3.08-6.10, chronological-age-matched with 15 children with normal hearing. Each participant performed 10 tasks evaluating different levels of phonological awareness abilities and phonological knowledge. The results showed that pre-schoolers with cochlear implants and their normal hearing peers had similar levels of syllable awareness, phoneme awareness and rhyme awareness. However, cochlear implant users showed significantly poorer performance on tone awareness and phonological knowledge tasks than their normal hearing peers. Cantonese-speaking pre-schoolers with cochlear implants were able to develop phonological awareness. However, the cochlear implants might not provide enough tonal information for children with hearing impairment for tonal lexical comprehension. Incomplete speech and language stimulation may affect phonological knowledge development in Cantonese-speaking pre-schoolers with cochlear implants.

Cochlear implantation outcomes in children with Waardenburg syndrome

Waardenburg syndrome (WS) is an autosomal dominant disease, characterized by dystopia canthorum, hyperplasia of the eyebrows, heterochromia iridis, white forelock, and congenital sensori-neural hearing loss (SNHL). The aim of this study was to evaluate the outcome of cochlear implantation in children with WS and compare it with children with pure SNHL. In a prospective study we evaluated 336 cochlear implanted children from 2008 to 2010. The WS was diagnosed by its established criteria and for control group children without any dysmorphic features, anatomical, behavioral, and developmental disorders were also enrolled. We evaluated children of both groups 1 year after cochlear implantation by categories of auditory performance (CAP) and speech intelligibility rating (SIR) tests. Eighty-one children out of the total 336 who had SNHL were included in study. Out of these 75 (22.3%) were healthy and six (1.78%) had WS. Of the 75 healthy children 40 (53.3%) were girls, while of the six children with WS, three (50%) were girls. There was a significant difference in SIR between WS and cases with pure SNHL (2.67 ± 1.03 vs. 3.79 ± 1.11, p = 021) however, the difference was not significant in CAP (4 ± 1.26 vs. 5.13 ± 1.13, p = 0.082). Prevalence of WS was 1.78% at Baqiyatallah Cochlear Implant Center. One year after implantation there was no significant difference in auditory outcome; however, the difference in speech outcome was significant between WS and cases with pure SNHL.

Systematic review of the literature on the clinical effectiveness of the cochlear implant procedure in paediatric patients

The aim of this systematic review of the literature was to summarize the results of scientific publications on the clinical effectiveness of the cochlear implant (CI) procedure in children. The members of the Working Group first examined existing national and international literature and the principal international guidelines on the procedure. They considered as universally-accepted the usefulness/effectiveness of unilateral cochlear implantation in severely-profoundly deaf children. Accordingly, they focused attention on systematic reviews addressing clinical effectiveness and cost/efficacy of the CI procedure, with particular regard to the most controversial issues for which international consensus is lacking. The following aspects were evaluated: post-CI outcomes linked to precocity of CI; bilateral (simultaneous/ sequential) CI vs. unilateral CI and vs. bimodal stimulation; benefits derived from CI in deaf children with associated disabilities. With regard to the outcomes after implantation linked to precocity of intervention, there are few studies comparing post-CI outcomes in children implanted within the first year of life with those of children implanted in the second year. The selected studies suggest that children implanted within the first year of life present hearing and communicative outcomes that are better than those of children implanted after 12 months of age. Concerning children implanted after the first year of life, all studies confirm an advantage with respect to implant precocity, and many document an advantage in children who received cochlear implants under 18 months of age compared to those implanted at a later stage. With regard to bilateral CI, the studies demonstrate that compared to unilateral CI, bilateral CI offers advantages in terms of hearing in noise, sound localization and during hearing in a silent environment. There is, however, a wide range of variability. The studies also document the advantages after sequential bilateral CI. In these cases, a short interval between interventions, precocity of the first CI and precocity of the second CI are considered positive prognostic factors. In deaf children with associated disabilities, the studies analyzed evidence that the CI procedure is also suitable for children with disabilities associated with deafness, and that even these children may benefit from the procedure, even if these may be slower and inferior to those in children with isolated deafness, especially in terms of high communicative and perceptive skills.

Exploring factors that affect the age of cochlear implantation in children

OBJECTIVE

Early access to sound through early cochlear implantation has been widely advocated for children who do not derive sufficient benefit from acoustic amplification. Early identification through newborn hearing screening should lead to earlier intervention including earlier cochlear implantation when appropriate. Despite earlier diagnosis and the trend towards early implantation, many children are still implanted well into their preschool years. The purpose of this study was to examine the factors that affected late cochlear implantation in children with early onset permanent sensorineural hearing loss.

METHODS

Data were examined for 43 children with cochlear implants who were part of a group of 71 children with hearing loss enrolled in a Canadian outcomes study. Eighteen (41.9%) of the 43 children were identified through newborn screening and 25 (58.1%) through medical referral to audiology. Medical chart data were examined to determine age of hearing loss diagnosis, age at cochlear implant candidacy, and age at cochlear implantation. Detailed reviews were conducted to identify the factors that resulted in implantation more than 12 months after hearing loss confirmation.

RESULTS

The median age of diagnosis of hearing loss for all 43 children was 9.0 (IQR: 5.1, 15.8) months and a median of 9.1 (IQR: 5.6, 26.8) months elapsed between diagnosis and unilateral cochlear implantation. The median age at identification for the screened groups was 3.3 months (IQR: 1.4, 7.1) but age at implantation (median 15.8 months: IQR: 5.6, 37.1) was highly variable. Eighteen of 43 children (41.9%) received a cochlear implant more than 12 months after initial hearing loss diagnosis. For many children, diagnosis of hearing loss was not equivalent to the determination of cochlear implant candidacy. Detailed reviews of audiologic profiles and study data indicated that late implantation could be accounted for primarily by progressive hearing loss (11 children), complex medical conditions (4 children) and other miscellaneous factors (3 children).

CONCLUSIONS

This study suggests that a substantial number of children will continue to receive cochlear implants well beyond their first birthday primarily due to progressive hearing loss. In addition, other medical conditions may contribute to delayed decisions in pediatric cochlear implantation.

The Gap in Noise test in 11 and 12-year-old children

BACKGROUND

gap detection in 11 and 12-year-old children.

AIM

to investigate temporal resolution through the Gap in Noise test in children of 11 and 12 years in order to establish criteria of normal development.

METHOD

participants were 92 children, with ages of 11 and 12 years, enrolled in elementary school, with no evidences of otologic, and/or neurologic, and/or cognitive disorders, as well as with no history of learning difficulties or school failure. Besides that, participants' hearing thresholds were within normal limits and their verbal recognition in the dichotic test of digits was equal or superior to 95% of hits. All were submitted to the Gap in Noise test. The statistical analysis was performed by non-parametric tests with significance level of 0.05 (5%).

RESULTS

the average of the gap thresholds was 5.05 ms, and the average percentage of correct answers was 71.70%. There was no significant statistical difference between the responses by age (eleven and twelve years), by ear (right and left), by gender (male and female). However, when comparing the tests, it was observed that the 1st test showed a higher percentage of identifications of gap, statistically significant than the 2nd test.

CONCLUSION

in 78.27% of the population of this study, the gap thresholds were up to 5 ms, response recommended as normality reference for the age group searched.

Peer interactions of preschool children with and without hearing loss

PURPOSE

Little is known about the social interaction skills of children with severe to profound hearing loss (SPHL) in terms of how they manage conversational exchanges with peers. This study compared the initiation and response skills of children with SPHL with those of children with typical hearing during group play in integrated preschool programs.

METHOD

Two groups of 12 children were matched on a number of variables and assessed for intelligence, language, speech, and social development. All initiations, responses, and resulting interactions during 20 min of group play were transcribed and coded. Outcome measures included number and type of initiation strategies, number of responses, and length of interactions.

RESULTS

Despite poorer speech, language, and social development, there were no significant differences in initiation and response skills measured between children with SPHL and their matched peers. The small sample size may have made differences difficult to detect; however, playmates initiated interactions less often with the children with SPHL and ignored their initiations more often than those of other children.

CONCLUSIONS

Preschool children with SPHL were excluded from interactions by their playmates. Having age-appropriate language skills did not ensure successful peer interactions. Inclusive preschool programs may consider offering classroom-wide social skills training to enhance interaction opportunities.

The cost and benefit of juvenile training on adult perceptual skill

Sensory experience during development can modify the CNS and alter adult perceptual skills. While this principle draws support from deprivation or chronic stimulus exposure studies, the effect of training is addressed only in adults. Here, we asked whether a brief period of training during development can exert a unique impact on adult perceptual skills. Juvenile gerbils were trained to detect amplitude modulation (AM), a stimulus feature elemental to animal communication sounds. When the performance of these juvenile-trained animals was subsequently assessed in adulthood, it was superior to a control group that received an identical regimen of training as adults. The juvenile-trained animals displayed significantly better AM detection thresholds. This was not observed in an adult group that received only exposure to AM stimuli as juveniles. To determine whether enhanced adult performance was due solely to learning the conditioned avoidance procedure, juveniles were trained on frequency modulation (FM) detection, and subsequently assessed on AM detection as adults. These animals displayed significantly poorer AM detection thresholds than all other groups. Thus, training on a specific auditory task (AM detection) during development provided a benefit to performance on that task in adulthood, whereas an identical training regimen in adulthood did not bring about this enhancement. In contrast, there was a cost, in adulthood, following developmental training on a different task (FM detection). Together, the results demonstrate a period of heightened sensitivity in the developing CNS such that behavioral training in juveniles has a unique impact on adult behavioral capabilities.

A new measurement tool for speech development based on Ling's stages of speech acquisition in pediatric cochlear implant recipients

OBJECTIVES

With the rapid increase of pediatric cochlear implantation (CI), there exists a need for a standardized assessment tool regarding speech and communication skills in children with CI. However, the current testing tools are not appropriate for the longitudinal evaluation of young children after CI. The aims of this study were to describe a progressive testing tool developed for the evaluation of speech acquisition and production in young children who have undergone CI and to examine its validity.

METHODS

Sixty children younger than six years of age with CI participated in this study. A Korean version of Ling's stages (K-Ling) was developed based on the Ling speech teaching model to longitudinally assess phonologic and phonetic developments in young children after CI. The K-Ling, the Categories of Auditory Performance (CAP), and the Sequenced Language Scale for Infants (SELSI) were performed in the children with CI preoperatively and three, six, and 12 months postoperatively. Correlations among these three testing tools were analyzed.

RESULTS

Auditory, language, and speech skills assessed using the CAP, SELSI, and K-Ling improved continuously for 12 months in young children following CI. Strong correlations were obtained among K-Ling's level, CAP scores, and the equivalent age of SELSI; correlation indices ranged from 0.540 to 0.800.

CONCLUSIONS

The K-Ling was a valid evaluation tool regarding speech development in young children who are using CI and who are in the early stages of speech development. Longitudinal assessments of phonetic and phonologic developments may be attainable in young children using the K-Ling.

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

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

Sound localization skills in children who use bilateral cochlear implants and in children with normal acoustic hearing

OBJECTIVES

To measure sound source localization in children who have sequential bilateral cochlear implants (BICIs); to determine whether localization accuracy correlates with performance on a right-left discrimination task (i.e., spatial acuity); to determine whether there is a measurable bilateral benefit on a sound source identification task (i.e., localization accuracy) by comparing performance under bilateral and unilateral listening conditions; and to determine whether sound source localization continues to improve with longer durations of bilateral experience.

DESIGN

Two groups of children participated in this study: a group of 21 children who received BICIs in sequential procedures (5 to 14 years) and a group of 7 typically developing children with normal acoustic hearing (5 years). Testing was conducted in a large sound-treated booth with loudspeakers positioned on a horizontal arc with a radius of 1.2 m. Children participated in two experiments that assessed spatial hearing skills. Spatial hearing acuity was assessed with a discrimination task in which listeners determined whether a sound source was presented on the right or left side of center; the smallest angle at which performance on this task was reliably above chance is the minimum audible angle. Sound localization accuracy was assessed with a sound source identification task in which children identified the perceived position of the sound source from a multiloudspeaker array (7 or 15); errors are quantified using the root mean square (RMS) error.

RESULTS

Sound localization accuracy was highly variable among the children with BICIs, with RMS errors ranging from 19 to 56 degrees . Performance of the normal hearing group, with RMS errors ranging from 9 to 29 degrees was significantly better. Within the BICI group, in 11 of 21 children, RMS errors were smaller in the bilateral versus unilateral listening condition, indicating bilateral benefit. There was a significant correlation between spatial acuity and sound localization accuracy (R = 0.68, p < 0.01), suggesting that children who achieve small RMS errors tend to have the smallest minimum audible angles. Although there was large intersubject variability, testing of 11 children in the BICI group at two sequential visits revealed a subset of children who show improvement in spatial hearing skills over time.

CONCLUSIONS

A subset of children who use sequential BICIs can acquire sound localization abilities, even after long intervals between activation of hearing in the first- and second-implanted ears. This suggests that children with activation of the second implant later in life may be capable of developing spatial hearing abilities. The large variability in performance among the children with BICIs suggests that maturation of sound localization abilities in children with BICIs may be dependent on various individual subject factors such as age of implantation and chronological age.

Long-term language levels and reading skills in mandarin-speaking prelingually deaf children with cochlear implants

The aim of this study was to document receptive and expressive language levels and reading skills achieved by Mandarin-speaking children who had received cochlear implants (CIs) and used them for 4.75-7.42 years. The effects of possible associated factors were also analyzed. Standardized Mandarin language and reading tests were administered to 39 prelingually deaf children with Nucleus 24 devices. The Mandarin Chinese version of the Peabody Picture Vocabulary Test was used to assess their receptive vocabulary knowledge and the Revised Primary School Language Assessment Test for their receptive and expressive language skills. The Graded Chinese Character Recognition Test was used to test their written word recognition ability and the Reading Comprehension Test for their reading comprehension ability. Raw scores from both language and reading measurements were compared to normative data of nor- mal-hearing children to obtain standard scores. The results showed that the mean standard score for receptive vocabulary measurement and the mean T scores for the receptive language, expressive language and total language measurement were all in the low-average range in comparison to the normative sample. In contrast, the mean T scores for word and text reading comprehension were almost the same as for their age-matched hearing counterparts. Among all children with CIs, 75.7% scored within or above the normal range of their age-matched hearing peers on receptive vocabulary measurement. For total language, Chinese word recognition and reading scores, 71.8, 77 and 82% of children with CIs were age appropriate, respectively. A strong correlation was found between language and reading skills. Age at implantation and sentence perception scores account for 37% of variance for total language outcome. Sentence perception scores and preimplantation residual hearing were revealed to be associated with the outcome of reading comprehension. We concluded that by using standard tests, the language development and reading skill of Mandarin-speaking children who use CIs from a young age appear to fall within the normal range of their hearing age mates, at least after 4.8-7.4 years of experience. However, to fully evaluate the fine linguistic skills of these subjects, a more detailed study and longer follow-up period are needed.

Health economic analysis of screening

In this article health economic implications of screening are analysed. First, requirements screening programmes should fulfil are derived, and methodical standards of health economic evaluation are outlined.Using the example of newborn hearing screening, it is then examined if empirical studies meet the methodical requirements of health economic evaluation. Some deficits are realised: Health economic studies of newborn hearing screening are not randomised, most studies are even not controlled. Therefore, most studies do not present incremental, but only average cost-effectiveness ratios (i.e. cost per case identified). Furthermore, evidence on long-term outcomes of screening and early interventions is insufficient. In conclusion, there is a need for controlled trials to examine differences in identified cases, but particularly to examine long-term effects.

Peer relationships of deaf children with cochlear implants: predictors of peer entry and peer interaction success

This study investigated factors that affect the development of positive peer relationships among deaf children with cochlear implants. Ten 5- to 6-year-old deaf children with implants were observed under conditions varying peer context difficulty in a Peer Entry task. Results revealed better outcomes for deaf children interacting in one-on-one situations compared to interactions including two other hearing children and better performance among girls than boys. In addition, longer duration of implant use and higher self-esteem were associated with better performance on the Peer Task, which was in turn related to parental reports of children's social functioning outside the experimental situation. These findings contribute to the growing literature describing the benefits of cochlear implantation in the areas of communication and socialization, while pointing to interventions that may enhance deaf children's social competence.

[Deviant language development following cochlear implantation? Applicability of the parent questionnaire ELFRA-2]

BACKGROUND

The parent questionnaire ELFRA-2 is considered a valid tool for early detection of delayed language development in 2-year-old children. Applicability for children treated with cochlear implants (CI) is to be investigated.

METHODS

By means of the ELFRA-2 we documented longitudinally for up to 24 months post implantation language development in 27 children treated before 3 years of age. The critical developmental criteria (related to age) were applied to CI children (related to duration of CI use) and gender-related normative data were taken as a reference.

RESULTS

Only two boys were identified as showing a language delay after 2 years of CI use. However, using normative data 11-44% of the children performed below average. Development in girls was faster than in boys. The influence of preoperative hearing experience declined over time.

CONCLUSION

The critical developmental criteria of ELFRA-2 have proved to be unreliable for the identification of varying development after CI. Modified and gender-related evaluation is necessary.

Auditory development in early amplified children: factors influencing auditory-based communication outcomes in children with hearing loss

OBJECTIVE

The purpose of this study was to determine the influence of selected predictive factors, primarily age at fitting of amplification and degree of hearing loss, on auditory-based outcomes in young children with bilateral sensorineural hearing loss.

DESIGN

Forty-four infants and toddlers, first identified with mild to profound bilateral hearing loss, who were being fitted with amplification were enrolled in the study and followed longitudinally. Subjects were otherwise typically developing with no evidence of cognitive, motor, or visual impairment. A variety of subject factors were measured or documented and used as predictor variables, including age at fitting of amplification, degree of hearing loss in the better hearing ear, cochlear implant status, intensity of oral education, parent-child interaction, and the number of languages spoken in the home. These factors were used in a linear multiple regression analysis to assess their contribution to auditory-based communication outcomes. Five outcome measures, evaluated at regular intervals in children starting at age 3, included measures of speech perception (Pediatric Speech Intelligibility and Online Imitative Test of Speech Pattern Contrast Perception), speech production (Arizona-3), and spoken language (Reynell Expressive and Receptive Language).

RESULTS

The age at fitting of amplification ranged from 1 to 72 mo, and the degree of hearing loss ranged from mild to profound. Age at fitting of amplification showed the largest influence and was a significant factor in all outcome models. The degree of hearing loss was an important factor in the modeling of speech production and spoken language outcomes. Cochlear implant use was the other factor that contributed significantly to speech perception, speech production, and language outcomes. Other factors contributed sparsely to the models.

CONCLUSIONS

Prospective longitudinal studies of children are important to establish relationships between subject factors and outcomes. This study clearly demonstrated the importance of early amplification on communication outcomes. This demonstration required a participant pool that included children who have been fit at very early ages and who represent all degrees of hearing loss. Limitations of longitudinal studies include selection biases. Families who enroll tend to have high levels of education and rate highly on cooperation and compliance measures. Although valuable information can be extracted from prospective studies, not all factors can be evaluated because of enrollment constraints.

Estudo longitudinal da compreensão verbal de crianças usuárias de implante coclear

OBJETIVO: analisar a compreensão verbal de crianças surdas usuárias de implante coclear (IC) por meio de um estudo longitudinal. MÉTODOS: os participantes foram nove crianças surdas usuárias de IC. A idade cronológica das crianças variou entre quatro e oito anos e o tempo de uso do IC foi, em média, 1 ano e 6 meses na 1ª avaliação, 3 anos e 7 meses na 2ª avaliação e 4 anos e 9 meses na 3ª avaliação. As crianças foram avaliadas longitudinalmente por meio da Escala de Compreensão Verbal da RDLS. Os materiais usados foram brinquedos, objetos e figuras. Os dados foram analisados qualitativa e quantitativamente. RESULTADOS: os resultados mostraram que as crianças implantadas obtiveram uma evolução estatisticamente significante em relação às habilidades de linguagem receptiva. CONCLUSÃO: o estudo comprova a efetividade do IC para o desenvolvimento da compreensão verbal.

Phonological awareness, vocabulary, and reading in deaf children with cochlear implants

PURPOSE

To explore the phonological awareness skills of deaf children with cochlear implants (CIs) and relationships with vocabulary and reading development.

METHOD

Forty-three deaf children with implants who were between 5 and 15 years of age were tested; 21 had been implanted at around 2.5 years of age (Early CI group), and 22 had been implanted at around 5 years of age (Late CI group). Two control groups-a deaf hearing aided group (16 children) and a typically developing group of hearing children (19 children)-were also tested. All children received a battery of phonological processing tasks along with measures of reading, vocabulary, and speechreading. Analyses focus on deaf children within the normal IQ range (n = 53).

RESULTS

Age at cochlear implantation had a significant effect on vocabulary and reading outcomes when quotient scores were calculated. Individual differences in age at implant, duration of fit, phonological development, vocabulary development, auditory memory, visual memory, and speech intelligibility were all strongly associated with progress in reading for the deaf implanted children. Patterns differed somewhat depending on whether quotient scores or standard scores were used.

CONCLUSIONS

Cochlear implantation is associated with development of the oral language, auditory memory, and phonological awareness skills necessary for developing efficient word recognition skills. There is a benefit of earlier implantation.

Characterization of symbolic play in deaf children: case and control studies

BACKGROUND

Children with hearing loss do not acquire language at the same time nor at the same rate of normal hearing children because the learning process of oral language is essentially auditory. Child development consists in gradually acquiring motor and psychocognitive abilities. Entering the symbolic world is decisive for the child to reach higher levels of linguistic complexity.

AIM

To correlate symbolic play and aspects of child development in deaf children and in hearing children.

METHOD

Participants of this study were 32 children, of both genders, with ages between 2 and 6 years, age matched. All participants were submitted to the Evaluation of Symbolic Maturation and to the Denver Developmental Screening Test II. Sixteen participants presented moderate to profound sensory-neural hearing loss and composed the research group (RG); the remaining 16 children had normal hearing and composed the control group (CG).

RESULTS

Symbolism was observed in the play of 81.25% of RG and in 87.5% of CG. In the Denver Developmental Screening Test II, 100% of the RG was classified as being at risk. As for the CG, 94% of the children were classified as normal and the remaining 6% as being at risk (p<0.001).

CONCLUSION

A similar performance was observed between the groups for symbolic play. However, in a qualitative analysis, the RG presented less complex symbolic play than the CG. It was observed that the RG presented a performance in the symbolic play compatible to its performance in aspects of personal-social, refined motor and gross motor control in the Denver Developmental Screening Test II.

[Not Available]

The purpose of this study was to establish audiology referral protocols for post meningitis paediatric populations in two academic hospitals in Gauteng, South Africa. Specific objectives of this study included determining if audiological assessment referrals were made following infection; determining the time of referral post meningitis diagnosis; establishing what audiological assessments were conducted on this population, as well as determining any correlations between signs and symptoms of meningitis and referrals for audiology assessments. Medical records of 47 children admitted to hospital with a diagnosis of meningitis between the ages of birth and 6 years were reviewed following a retrospective record review design. Data relevant to the current study were obtained from hospital records and this was captured in a data spreadsheet. Both descriptive and inferential statistics were implemented in analysis of the data. Inferential statistics in the form of logistic regression analysis was used to establish any significant factor that may predict referral for audiological assessment. The findings indicated that almost half (40%) of the cases were not referred for audiological services. Of those cases referred for assessment, 89% were referred as in-patients before hospital discharge, with minimal referrals occurring after discharge from hospital. Screening, rather than diagnostic audiology measures were conducted on a majority of the cases. Logistic regression analysis identified fever as the only predictor variable (p<0.01) for audiological assessment referral. Results from this study highlight the need for the establishment of audiology referral protocols for paediatric meningitis populations to ensure that early identification and early intervention occurs.

Narrative competence among hearing-impaired and normal-hearing children: analytical cross-sectional study

CONTEXT AND OBJECTIVE

oral narrative is a means of language development assessment. However, standardized data for deaf patients are scarce. The aim here was to compare the use of narrative competence between hearing-impaired and normal-hearing children.

DESIGN AND SETTING

analytical cross-sectional study at the Department of Speech-Language and Hearing Sciences, Universidade Federal de São Paulo.

METHODS

twenty-one moderately to profoundly bilaterally hearing-impaired children (cases) and 21 normal-hearing children without language abnormalities (controls), matched according to sex, age, schooling level and school type, were studied. A board showing pictures in a temporally logical sequence was presented to each child, to elicit a narrative, and the child's performance relating to narrative structure and cohesion was measured. The frequencies of variables, their associations (Mann-Whitney test) and their 95% confidence intervals was analyzed.

RESULTS

the deaf subjects showed poorer performance regarding narrative structure, use of connectives, cohesion measurements and general punctuation (P < 0.05). There were no differences in the number of propositions elaborated or in referent specification between the two groups. The deaf children produced a higher proportion of orientation-related propositions (P = 0.001) and lower proportions of propositions relating to complicating actions (P = 0.015) and character reactions (P = 0.005).

CONCLUSION

hearing-impaired children have abnormalities in different aspects of language, involving form, content and use, in relation to their normal-hearing peers. Narrative competence was also associated with the children's ages and the school type.

Spoken word recognition in toddlers who use cochlear implants

PURPOSE

The purpose of this study was to assess the time course of spoken word recognition in 2-year-old children who use cochlear implants (CIs) in quiet and in the presence of speech competitors.

METHOD

Children who use CIs and age-matched peers with normal acoustic hearing listened to familiar auditory labels, in quiet or in the presence of speech competitors, while their eye movements to target objects were digitally recorded. Word recognition performance was quantified by measuring each child's reaction time (i.e., the latency between the spoken auditory label and the first look at the target object) and accuracy (i.e., the amount of time that children looked at target objects within 367 ms to 2,000 ms after the label onset).

RESULTS

Children with CIs were less accurate and took longer to fixate target objects than did age-matched children without hearing loss. Both groups of children showed reduced performance in the presence of the speech competitors, although many children continued to recognize labels at above-chance levels.

CONCLUSION

The results suggest that the unique auditory experience of young CI users slows the time course of spoken word recognition abilities. In addition, real-world listening environments may slow language processing in young language learners, regardless of their hearing status.

Análise comparativa da linguagem oral de crianças ouvintes e surdas usuárias de implante coclear

OBJETIVO: analisar e comparar a expressão verbal de crianças ouvintes e crianças usuárias de implante coclear. MÉTODOS: os participantes foram 12 crianças ouvintes, entre 4 anos e 2 mês e 4 anos e 11 meses, e 10 crianças portadoras de perda auditiva neurossensorial profunda, usuárias de implante coclear, de 4 anos e 3 meses a 5 anos e 0 meses. As crianças foram avaliadas por meio da Escala de Expressão Verbal da Reynell Developmental Language Scales (RDLS), versão americana, adaptada por Fortunato-Queiroz (2007). Os dados dos dois grupos de crianças foram analisados e comparados entre si. RESULTADOS: as crianças surdas obtiveram um desempenho inferior ao das crianças ouvintes quanto à expressão verbal. Três crianças implantadas obtiveram resultados próximos ao considerado como padrão pela pesquisa, ou seja, aos resultados das crianças ouvintes. CONCLUSÃO: os resultados obtidos pelas crianças deficientes auditivas, usuárias de IC, foram inferiores aos seus pares ouvintes. As crianças surdas que apresentaram as maiores pontuações foram as que possuíam maior tempo de uso do IC e menor tempo de privação sensorial.

Music in the lives of deaf children with cochlear implants

Present-day cochlear implants provide good temporal cues and coarse spectral cues. In general, these cues are adequate for perceiving speech in quiet backgrounds and for young children's acquisition of spoken language. They are inadequate, however, for conveying the rich pitch-patterning of music. As a result, many adults who become implant users after losing their hearing find music disappointing or unacceptable. By contrast, child implant users who were born deaf or became deaf as infants or toddlers typically find music interesting and enjoyable. They recognize popular songs that they hear regularly when the test materials match critical features of the original versions. For example, they can identify familiar songs from the original recordings with words and from versions that omit the words but preserve all other cues. They also recognize theme songs from their favorite television programs when presented in original or somewhat altered form. The motivation of children with implants for listening to music or melodious speech is evident well before they understand language. Within months after receiving their implant, they prefer singing to silence. They also prefer speech in the maternal style to typical adult speech and the sounds of their native language-to-be to those of a foreign language. An important task of future research is to ascertain the relative contributions of perceptual and motivational factors to the apparent differences between child and adult implant users.

The effects of bilateral electric and bimodal electric--acoustic stimulation on language development

There is no doubt that cochlear implants have improved the spoken language abilities of children with hearing loss, but delays persist. Consequently, it is imperative that new treatment options be explored. This study evaluated one aspect of treatment that might be modified, that having to do with bilateral implants and bimodal stimulation. A total of 58 children with at least one implant were tested at 42 months of age on four language measures spanning a continuum from basic to generative in nature. When children were grouped by the kind of stimulation they had at 42 months (one implant, bilateral implants, or bimodal stimulation), no differences across groups were observed. This was true even when groups were constrained to only children who had at least 12 months to acclimatize to their stimulation configuration. However, when children were grouped according to whether or not they had spent any time with bimodal stimulation (either consistently since their first implant or as an interlude to receiving a second) advantages were found for children who had some bimodal experience, but those advantages were restricted to language abilities that are generative in nature. Thus, previously reported benefits of simultaneous bilateral implantation early in a child's life may not extend to generative language. In fact, children may benefit from a period of bimodal stimulation early in childhood because low-frequency speech signals provide prosody and serve as an aid in learning how to perceptually organize the signal that is received through a cochlear implant.

Estimating the Influence of Cochlear Implantation on Language Development in Children

Research studies reviewed here have identified a wide variety of factors that may influence a child's auditory, speech and language development following cochlear implantation. Intrinsic characteristics of the implanted child, including gender, family socio-economic status, age at onset of hearing loss and pre-implant residual hearing may predispose a child to greater or lesser post-implant benefit. Intervention characteristics that may influence outcome include age of the child when deafness is identified and amplification and habilitation is initiated, the communication mode used with the child and the type of classroom/therapy employed. Characteristics of the implant itself include generation of technology used, the age of the child when implant stimulation is initiated, and the amount of time the child has used the implant. These factors interact in unpredictable ways, so that isolated correlations between predictor variables and outcome scores may be difficult to interpret. Results for two independent samples of orally-educated children tested by different laboratories were compared using multiple regression analysis to illustrate interactions among predictor variables. Four predictor variables accounted for a similar proportion of variance (23% and 24%) in receptive vocabulary (PPVT) outcome scores in each sample. A unique predictor was then added to each analysis. The addition of pre-implant aided threshold not only increased the total variance accounted for to almost 40%, but also increased the effect of implant age as a predictor variable. A different result was observed in the other sample, were the added predictor variable was nonverbal IQ, where the estimated contribution of implant age was reduced. The current analysis suggests that future analyses minimally control for independent contributions of implant age, nonverbal IQ, and pre-implant aided thresholds when examining expected outcomes. Children in both samples who received a cochlear implant sometime between their first and second birthday achieved age-appropriate oral receptive vocabulary levels during preschool.

Developmental constraints on language development in children with cochlear implants

Research on pediatric cochlear implantation has frequently shown that speech perception, speech production, and language outcomes are better for children who are implanted earlier in life than later. These findings are often explained on the grounds that earlier implantation takes advantage of a critical or sensitive period. This paper reviews the literature concerning sensitive periods within the framework of speech and language development. It particularly emphasizes two alternate mechanisms proposed for these periods: an experience-independent mechanism, and an experience-dependent mechanism. Based on this literature review we proposed that research in the field of pediatric cochlear implantation needs to carefully define what kind of evidence is needed to reflect a sensitive period for speech and language learning. The field also needs to consider designing studies that allow the viability of these two mechanisms to be tested. An example of such a study is provided within.