Nonword repetition by children with cochlear implants: accuracy ratings from normal-hearing listeners

Speaking Rate, Immediate Memory, and Grammatical Processing in Prelingual Cochlear Implant Recipients

PURPOSE

This study examined the extent to which prelingual cochlear implant (CI) users show a slowed speaking rate compared with typical-hearing (TH) talkers when repeating various speech stimuli and whether the slowed speech of CI users relates to their immediate verbal memory.

METHOD

Participants included 10 prelingually deaf teenagers who received CIs before the age of 5 years and 10 age-matched TH teenagers. Participants repeated nonword syllable strings, word strings, and center-embedded sentences, with conditions balanced for syllable length and metrical structure. Participants' digit span forward and backward scores were collected to measure immediate verbal memory. Speaking rate data were analyzed using a mixed-design, repeated-measures analysis of variance, and the relationships between speaking rate and digit spans were evaluated by Pearson correlation.

RESULTS

Participants with CIs spoke more slowly than their TH peers during the sentence repetition task but not in the nonword string and word string repetition tasks. For the CI group, significant correlations emerged between speaking rate and digit span scores (both forward and backward) for the sentence repetition task but not for the nonword string or word string repetition task. For the TH group, no significant correlations were found.

CONCLUSIONS

The findings indicate a relation between slowed speech production, reduced immediate verbal memory, and diminished language capabilities of prelingual CI users, particularly for syntactic processing. These results support theories claiming that immediate memory, including components of a central executive, influences the speaking rate of these talkers. Implications for therapies designed to increase speech fluency in CI recipients are discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21644795.

Effects of Segmental and Suprasegmental Speech Perception on Reading in Pediatric Cochlear Implant Recipients

PURPOSE

The aim of this study was to determine whether suprasegmental speech perception contributes unique variance in predictions of reading decoding and comprehension for prelingually deaf children using two devices, at least one of which is a cochlear implant (CI).

METHOD

A total of 104, 5- to 9-year-old CI recipients completed tests of segmental perception (e.g., word recognition in quiet and noise, recognition of vowels and consonants in quiet), suprasegmental perception (e.g., talker and stress discrimination, nonword stress repetition, and emotion identification), and nonverbal intelligence. Two years later, participants completed standardized tests of reading decoding and comprehension. Using regression analyses, the unique contribution of suprasegmental perception to reading skills was determined after controlling for demographic characteristics and segmental perception performance.

RESULTS

Standardized reading scores of the CI recipients increased with nonverbal intelligence for both decoding and comprehension. Female gender was associated with higher comprehension scores. After controlling for gender and nonverbal intelligence, segmental perception accounted for approximately 4% and 2% of the variance in decoding and comprehension, respectively. After controlling for nonverbal intelligence, gender, and segmental perception, suprasegmental perception accounted for an extra 4% and 7% unique variance in reading decoding and reading comprehension, respectively.

CONCLUSIONS

Suprasegmental perception operates independently from segmental perception to facilitate good reading outcomes for these children with CIs. Clinicians and educators should be mindful that early perceptual skills may have long-term benefits for literacy. Research on how to optimize suprasegmental perception, perhaps through hearing-device programming and/or training strategies, is needed.

Considerations in pediatric device candidacy: An emphasis on spoken language

As cochlear implant (CI) candidacy expands to consider children with more residual hearing, the use of a CI and a hearing aid (HA) at the non-implanted ear (bimodal devices) is increasing. This case study examines the contributions of acoustic and electric input to speech perception performance for a pediatric bimodal device user (S1) who is a borderline bilateral cochlear implant candidate. S1 completed a battery of perceptual tests in CI-only, HA-only and bimodal conditions. Since CIs and HAs differ in their ability to transmit cues related to segmental and suprasegmental perception, both types of perception were tested. Performance in all three device conditions were generally similar across tests, showing no clear device-condition benefit. Further, S1's spoken language performance was compared to those of a large group of children with prelingual severe-profound hearing loss who used two devices from a young age, at least one of which was a CI. S1's speech perception and language scores were average or above-average compared to these other pediatric CI recipients. Both segmental and suprasegmental speech perception, and spoken language skills should be examined to determine the broad-scale performance level of bimodal recipients, especially when deciding whether to move from bimodal devices to bilateral CIs.

Spectral Modulation Detection Performance and Speech Perception in Pediatric Cochlear Implant Recipients

PURPOSE

The aims of this study were, for pediatric cochlear implant (CI) recipients, (a) to determine the effect of age on their spectral modulation detection (SMD) ability and compare their age effect to that of their typically hearing (TH) peers; (b) to identify demographic, cognitive, and audiological factors associated with SMD ability; and (c) to determine the unique contribution of SMD ability to segmental and suprasegmental speech perception performance.

METHOD

A total of 104 pediatric CI recipients and 38 TH peers (ages 6-11 years) completed a test of SMD. CI recipients completed tests of segmental (e.g., word recognition in noise and vowels and consonants in quiet) and suprasegmental (e.g., talker discrimination, stress discrimination, and emotion identification) perception, nonverbal intelligence, and working memory. Regressions analyses were used to examine the effects of group and age on percent-correct SMD scores. For the CI group, the effects of demographic, audiological, and cognitive variables on SMD performance and the effects of SMD on speech perception were examined.

RESULTS

The TH group performed significantly better than the CI group on SMD. Both groups showed better performance with increasing age. Significant predictors of SMD performance for the CI group were age and nonverbal intelligence. SMD performance predicted significant variance in segmental and suprasegmental perception. The variance predicted by SMD performance was nearly double for suprasegmental than for segmental perception.

CONCLUSIONS

Children in the CI group, on average, scored lower than their TH peers. The slopes of improvement in SMD with age did not differ between the groups. The significant effect of nonverbal intelligence on SMD performance in CI recipients indicates that difficulties inherent in the task affect outcomes. SMD ability predicted speech perception scores, with a more prominent role in suprasegmental than in segmental speech perception. SMD ability may provide a useful nonlinguistic tool for predicting speech perception benefit, with cautious interpretation based on age and cognitive function.

The importance of working memory capacity for improving speech in noise comprehension in children with hearing aid

BACKGROUND

One of the most common complaints of hearing aid users is difficulty in receiving speech in noise which is very important for all hearing impaired specially children with limited auditory and language experiences. Since working memory plays a significant role in speech perception, especially in challenging auditory situations such as background noise, it is likely that differences in its performance and capacity may impair the ability to understand speech in noise in hearing aid users. Therefore, we aimed to compare memory capacity between two groups of children using hearing aids in both ears, who differed only in the ability to understand speech in noise.

METHODS

In this cross-sectional study, 31 children with moderate to severe hearing impairment and the same medical and demographical conditions that using bilateral hearing aids, were examined. These students were divided into two groups according to the scores obtained in speech comprehension as follows: group one (high performance) included students whose SNR loss score in BKB-Speech In Noise test was equal or less than 7, and group two (low performance) included students whose SNR loss score was more than 7. Then, the scores of auditory working memory tests were examined in these two groups.

RESULTS

The scores of two working memory tests of forward and backward digit span between the two groups no differed significantly based on statistical findings (P = 0.06). But The score of working memory test of non-word repetition differed significantly between the two groups (P = 0.03) A significant correlation was found between the scores of speech comprehension in noise test and working memory tests, including forward (P = 0.004) and backward digit (P = 0.002) span tests and non-word repetition test (P = 0.000) in all subjects.

CONCLUSION

The significant correlation founded between speech perception in noise scores and working memory span, indicating the importance of working memory capacity in the ability to understand speech in noise in children with hearing aids.

Exploring the Types of Stories Hearing Parents Tell About Rearing their Children Who Use Cochlear Implants

OBJECTIVES

The majority of children born in the United States with hearing loss (HL) are born to parents with hearing. Many of these parents ultimately choose cochlear implantation for their children. There are now decades of research showing which these children's speech, language, listening, and education seem to benefit from cochlear implantation. To date, however, we know little about the experiences of the parents who guided these children throughout their journeys. We propose that elucidating the types of stories these parents tell is a first step toward understanding their varied experiences and has the potential to ultimately improve healthcare outcomes for both children and their families. Thus, to better understand parents' experience, we asked the following research question: what types of stories do parents with hearing tell about rearing their children with HL who use cochlear implants?

DESIGN

In this prospective qualitative study, we used a narrative approach. Specifically, we conducted narrative interviews with 20 hearing parents who are rearing young children (mean age = 5.4 years) born with HL who use cochlear implants. We then used thematic narrative analysis to identify recurring themes throughout the narratives that coalesced into the types of stories parents told about their experiences.

FINDINGS

Thematic narrative analysis revealed five story types: (1) stories of personal growth, (2) proactive stories, (3) stories of strain and inundation, (4) detached stories, and (5) stories of persistence.

CONCLUSIONS

In the present study, different types of stories emerged from parents' experiences that share common events-a family's baby is identified at birth with unexpected permanent HL, the family chooses to pursue cochlear implantation for their child, and then the family raises said pediatric cochlear implant user into adulthood. Despite these similarities, the stories also varied in their sensemaking. Some parents told stories in which a positive life narrative turned bad, whereas others told stories in which a narrative of surviving turned into one of thriving. These findings specifically contribute to the field of hearing healthcare by providing professionals with insight into parents' sensemaking via the types of stories they shared centered on their perceptions and experiences following their child's diagnosis of HL and their decision to pursue cochlear implantation.

The Limits of "Communication Mode" as a Construct

Questions about communication mode (a.k.a. "communication options" or "communication opportunities") remain among the most controversial issues in the many fields that are concerned with the development and well-being of children (and adults) who are d/Deaf or hard of hearing. In this manuscript, we argue that a large part of the reason that this debate persists is due to limitations of the construct itself. We focus on what we term "the crucial question": namely, what kind of experience with linguistic input during infancy and toddlerhood is most likely to result in mastery of at least one language (spoken or signed) by school entry. We argue that the construct of communication mode-as currently construed-actively prevents the discovery of compelling answers to that question. To substantiate our argument, we present a review of a relevant subset of the recent empirical literature and document the prevalence of our concerns. We conclude by articulating the desiderata of an alternative construct that, if appropriately measured, would have the potential to yield answers to what we identify as "the crucial question."

High-Variability Sentence Recognition in Long-Term Cochlear Implant Users: Associations With Rapid Phonological Coding and Executive Functioning

OBJECTIVES

The objective of the present study was to determine whether long-term cochlear implant (CI) users would show greater variability in rapid phonological coding skills and greater reliance on slow-effortful compensatory executive functioning (EF) skills than normal-hearing (NH) peers on perceptually challenging high-variability sentence recognition tasks. We tested the following three hypotheses: First, CI users would show lower scores on sentence recognition tests involving high speaker and dialect variability than NH controls, even after adjusting for poorer sentence recognition performance by CI users on a conventional low-variability sentence recognition test. Second, variability in fast-automatic rapid phonological coding skills would be more strongly associated with performance on high-variability sentence recognition tasks for CI users than NH peers. Third, compensatory EF strategies would be more strongly associated with performance on high-variability sentence recognition tasks for CI users than NH peers.

DESIGN

Two groups of children, adolescents, and young adults aged 9 to 29 years participated in this cross-sectional study: 49 long-term CI users (≥7 years) and 56 NH controls. All participants were tested on measures of rapid phonological coding (Children's Test of Nonword Repetition), conventional sentence recognition (Harvard Sentence Recognition Test), and two novel high-variability sentence recognition tests that varied the indexical attributes of speech (Perceptually Robust English Sentence Test Open-set test and Perceptually Robust English Sentence Test Open-set test-Foreign Accented English test). Measures of EF included verbal working memory (WM), spatial WM, controlled cognitive fluency, and inhibition concentration.

RESULTS

CI users scored lower than NH peers on both tests of high-variability sentence recognition even after conventional sentence recognition skills were statistically controlled. Correlations between rapid phonological coding and high-variability sentence recognition scores were stronger for the CI sample than for the NH sample even after basic sentence perception skills were statistically controlled. Scatterplots revealed different ranges and slopes for the relationship between rapid phonological coding skills and high-variability sentence recognition performance in CI users and NH peers. Although no statistically significant correlations between EF strategies and sentence recognition were found in the CI or NH sample after use of a conservative Bonferroni-type correction, medium to high effect sizes for correlations between verbal WM and sentence recognition in the CI sample suggest that further investigation of this relationship is needed.

CONCLUSIONS

These findings provide converging support for neurocognitive models that propose two channels for speech-language processing: a fast-automatic channel that predominates whenever possible and a compensatory slow-effortful processing channel that is activated during perceptually-challenging speech processing tasks that are not fully managed by the fast-automatic channel (ease of language understanding, framework for understanding effortful listening, and auditory neurocognitive model). CI users showed significantly poorer performance on measures of high-variability sentence recognition than NH peers, even after simple sentence recognition was controlled. Nonword repetition scores showed almost no overlap between CI and NH samples, and correlations between nonword repetition scores and high-variability sentence recognition were consistent with greater reliance on engagement of fast-automatic phonological coding for high-variability sentence recognition in the CI sample than in the NH sample. Further investigation of the verbal WM-sentence recognition relationship in CI users is recommended. Assessment of fast-automatic phonological processing and slow-effortful EF skills may provide a better understanding of speech perception outcomes in CI users in the clinical setting.

Effects of Early Acoustic Hearing on Speech Perception and Language for Pediatric Cochlear Implant Recipients

Purpose The overall goal of the current study was to identify an optimal level and duration of acoustic experience that facilitates language development for pediatric cochlear implant (CI) recipients-specifically, to determine whether there is an optimal duration of hearing aid (HA) use and unaided threshold levels that should be considered before proceeding to bilateral CIs. Method A total of 117 pediatric CI recipients (ages 5-9 years) were given speech perception and standardized tests of receptive vocabulary and language. The speech perception battery included tests of segmental perception (e.g., word recognition in quiet and noise, and vowels and consonants in quiet) and of suprasegmental perception (e.g., talker and stress discrimination, and emotion identification). Hierarchical regression analyses were used to determine the effects of speech perception on language scores, and the effects of residual hearing level (unaided pure-tone average [PTA]) and duration of HA use on speech perception. Results A continuum of residual hearing levels and the length of HA use were represented by calculating the unaided PTA of the ear with the longest duration of HA use for each child. All children wore 2 devices: Some wore bimodal devices, while others received their 2nd CI either simultaneously or sequentially, representing a wide range of HA use (0.03-9.05 years). Regression analyses indicate that suprasegmental perception contributes unique variance to receptive language scores and that both segmental and suprasegmental skills each contribute independently to receptive vocabulary scores. Also, analyses revealed an optimal duration of HA use for each of 3 ranges of hearing loss severity (with mean PTAs of 73, 92, and 111 dB HL) that maximizes suprasegmental perception. Conclusions For children with the most profound losses, early bilateral CIs provide the greatest opportunity for developing good spoken language skills. For those with moderate-to-severe losses, however, a prescribed period of bimodal use may be more advantageous for developing good spoken language skills.

Speech Production Accuracy and Variability in Monolingual and Bilingual Children With Cochlear Implants: A Comparison to Their Peers With Normal Hearing

Purpose This study investigates consonant and vowel accuracy and whole-word variability (also called token-to-token variability or token-to-token inconsistency) in bilingual Spanish-English and monolingual English-speaking children with cochlear implants (CIs) compared to their bilingual and monolingual peers with normal hearing (NH). Method Participants were 40 children between 4;6 and 7;11 (years;months; M _age = 6;2), n = 10 each in 4 participant groups: bilingual Spanish-English with CIs, monolingual English with CIs, bilingual Spanish-English with NH, and monolingual English with NH. Spanish and English word lists consisting of 20 words of varying length were generated, and 3 productions of each word were analyzed for percent consonants correct, percent vowels correct, and the presence of any consonant and/or vowel variability. Results Children with CIs demonstrated lower accuracy and more whole-word variability than their peers with NH. There were no differences in rates of accuracy or whole-word variability between bilingual and monolingual children matched on hearing status, and bilingual children had lower accuracy and greater whole-word variability in English than in Spanish. Conclusions High rates of whole-word variability are prevalent in the speech of children with CIs even after many years of CI experience, and bilingual language exposure does not appear to negatively impact phonological development in children with CIs. Contributions to our understanding of underlying sources of speech production variability and clinical implications are discussed.

Enhancing Working Memory Capacity in Persian Cochlear Implanted Children: A Clinical Trial Study

INTRODUCTION

Sensory deprivations such as hearing impairment that affect sensory input have a secondary impact on cognitive functions such as working memory (WM). WM capacity is an important cognitive component that processes language-related activities. Moreover, several studies have shown a deficit in WM in children with a cochlear implant (CI). We aimed to assess the performance of children with CIs in pre- and post-training sessions and compare their scores on a battery of WM tests to investigate the efficacy of a WM training program.

MATERIALS AND METHODS

Twenty-five children aged 7-10 years with a CI participated in this study. To train their WM, a computer game was used. In order to examine auditory WM, a test battery including standardized digit span (forward and backward variations), non-word and sentence repetition (subtest of the Test of Language Development-Primary) were assessed in pre- and post-training test sessions at Shiraz Implant Center.

RESULTS

There were statistically significant differences between pre- and post-training test scores on all subtests. Test score differences were statistically significant for forward digit span (P=0.003), backward digit span (P=0.001), non-word repetition (P=0.001), and sentence repetition tasks (P=0.003) before and after training sessions.

CONCLUSION

Training may enhance WM capacity. With regards to the importance of WM in literacy and learning, it seems applying such intervention programs may be helpful in the rehabilitation of implanted children.

Common Versus Unique Findings on Processing-Based Task Performance in Korean Speaking Children With Cochlear Implants

HYPOTHESIS

To better understand individual variability by examining overall neurocognitive underlying features in children with cochlear implants (CIs), and to investigate whether previous findings hold constant in Asian-language users.

BACKGROUND

Studies have tried to explain the individual variability in children with CIs. However, performance on experience-dependent tasks does not seem to be sensitive enough to explain the underlying reason why children have language difficulties even after the surgical procedure. Thus, this current research has focused on underlying neurocognitive functions to better explain the reason for the wide variability in this population.

METHODS

Using a separate univariate analysis paradigm, performance on processing-based tasks was compared between children with CIs and children with normal hearing. A total of 34 children ranging from 10 to 12 years old participated in the study. There were two different categories of processing-based tasks tapping processing capacity and processing speed. This study used nonword repetition (NWR), competing language processing task (CLPT), and counting span (CS) for examining processing capacity, while rapid naming (RAN) in color, shape, and color shape were used to investigate processing speed.

RESULTS

Children with NH outperformed children with CIs on all processing-capacity tasks, except CS. Children with CIs performed similarly to children with NH on processing speed tasks.

CONCLUSIONS

We found children with CIs still experienced difficulties with processing capacity. Due to cross-linguistic features, we also discovered some interesting findings that differed from previous studies. Lastly, we found processing speed was fairly intact in children with CIs, which is a new finding.

Working memory in Farsi-speaking children with normal development and cochlear implant

AIM AND BACKGROUND

Working memory has an important role in language acquisition and development of cognition skills. The ability of encoding, storage and retrieval of phonological codes, as activities of working memory, acquired by audition sense. Children with cochlear implant experience a period that they are not able to perceive sounds. In order to assess the effect of hearing on working memory, we investigated working memory as a cognition skill in children with normal development and cochlear implant.

METHODS

Fifty students with normal hearing and 50 students with cochlear implant aged 5-7 years participated in this study. Children educated in the preschool, the first and second grades. Children with normal development were matched based on age, gender, and grade of education with cochlear implant. Two components of working memory including phonological loop and central executive were compared between two groups. Phonological loop assessed by nonword repetition task and forward digit span. To assess central executive component backward digit span was used. The developmental trend was studied in children with normal development and cochlear implant as well. The effect of age at implantation in children with cochlear implants on components of working memory was investigated.

RESULTS

There are significant differences between children with normal development and cochlear implant in all tasks that assess working memory (p < 0.001). The children's age at implantation was negatively correlated with all tasks (p < 0.001). In contrast, duration of usage of cochlear implant set was positively correlated with all tasks (p < 0.001). The comparison of working memory between different grades showed significant differences both in children with normal development and in children with cochlear implant (p < 0.05).

CONCLUSION

These results implied that children with cochlear implant may experience difficulties in working memory. Therefore, these children have problems in encoding, practicing, and repeating phonological units. The results also suggested working memory develops when the child grows up. In cochlear implant children, with decreasing age at implantation and increasing their experience in perceiving sound, working memory skills improved.

Nonword repetition as a predictor of long-term speech and language skills in children with cochlear implants

HYPOTHESIS

The rapid phonological processing skills of children with cochlear implants early in life (ages 8-10), as measured by nonword repetition performance, will predict their language development 8 years later (ages 16-18). This core processing ability will also correlate with concurrent measures of language at both ages of testing.

BACKGROUND

Understanding the causes of the wide range of performance in pediatric cochlear implant users currently constitutes a major barrier to clinical and research progress in the field. Research into children's neurocognitive abilities such as working memory capacity and verbal rehearsal speed, in addition to conventional demographic variables, has shown that these foundational skills play a key role in determining outcomes. Here, we investigate the impact of rapid phonological processing, an ability which is critical in spoken language use, for children with cochlear implants.

METHODS

Fifty-two deaf children with cochlear implants completed a battery of 14 clinical and research measures of language, neurocognitive, and nonword repetition skills in 2 testing sessions 8 years apart.

RESULTS

Performance on the nonword repetition task at both testing sessions correlated significantly with concurrent language abilities. Importantly, nonword repetition accuracy at age 8 to 10 also significantly predicted performance on measures of language ability at age 16 to 18 in a wide range of domains, from speech intelligibility to sentence recognition in noise. These relations were significant even when other neurocognitive measures were controlled.

CONCLUSION

Early nonword repetition performance in children with cochlear implants predicts later language development and, therefore, may identify those children at high risk for poor outcomes.

Speech intelligibility and prosody production in children with cochlear implants

OBJECTIVES

The purpose of the current study was to examine the relation between speech intelligibility and prosody production in children who use cochlear implants.

METHODS

The Beginner's Intelligibility Test (BIT) and Prosodic Utterance Production (PUP) task were administered to 15 children who use cochlear implants and 10 children with normal hearing. Adult listeners with normal hearing judged the intelligibility of the words in the BIT sentences, identified the PUP sentences as one of four grammatical or emotional moods (i.e., declarative, interrogative, happy, or sad), and rated the PUP sentences according to how well they thought the child conveyed the designated mood.

RESULTS

Percent correct scores were higher for intelligibility than for prosody and higher for children with normal hearing than for children with cochlear implants. Declarative sentences were most readily identified and received the highest ratings by adult listeners; interrogative sentences were least readily identified and received the lowest ratings. Correlations between intelligibility and all mood identification and rating scores except declarative were not significant.

DISCUSSION

The findings suggest that the development of speech intelligibility progresses ahead of prosody in both children with cochlear implants and children with normal hearing; however, children with normal hearing still perform better than children with cochlear implants on measures of intelligibility and prosody even after accounting for hearing age. Problems with interrogative intonation may be related to more general restrictions on rising intonation, and the correlation results indicate that intelligibility and sentence intonation may be relatively dissociated at these ages.

LEARNING OUTCOMES

As a result of this activity, readers will be able to describe (1) methods for measuring speech intelligibility and prosody production in children with cochlear implants and children with normal hearing, (2) the differences between children with normal hearing and children with cochlear implants on measures of speech intelligibility and prosody production, and (3) the relations between speech intelligibility and prosody production in children with cochlear implants and children with normal hearing.

Cognitive Skills and Academic Achievement of Deaf Children with Cochlear Implants

Objective

To compare cognitive performance between children with cochlear implants (CI) and normal-hearing peers; provide information about correlations between cognitive performance, basic academic achievement, and medical/audiological and social background variables; and assess the predictor quality of these variables for cognition.

Study Design

Cross-sectional study with comparison group, diagnostic test assessment.

Setting

Data were collected in the authors’ clinic (children with CI) and in Austrian schools (normal-hearing children).

Subjects and Methods

Forty children with CI (of the initial 65 children eligible for this study), aged 7 to 11 years, and 40 normal-hearing children, matched by age and sex, were tested with (a) the Culture Fair Intelligence Test (CFIT); (b) the Number Sequences subtest of the Heidelberger Rechentest 1-4 (HRT); (c) Comprehension, (d) Coding, (e) Digit Span, and (f) Vocabulary subtests of HAWIK III (German WISC III); (g) the Corsi Block Tapping Test; (h) the Arithmetic Operations subtests of the HRT; and (i) Salzburger Lese–Screening (SLS, reading). In addition, medical, audiological, social, and educational data from children with CI were collected.

Results

The children with CI equaled normal-hearing children in (a), (d), (e), (g), (h), and (i) and performed significantly worse in (b), (c) and (f). Background variables correlate significantly with cognitive skills and academic achievement. Medical/audiological variables explain 44.3% of the variance in CFT1 (CFIT, younger children). Social variables explain 55% of CFT1 and 24.5% of the Corsi test.

Conclusions

This study augments the knowledge about cognitive skills and academic skills of children with CI. Cognitive performance is dependent on the early feasibility to hear and the social/educational background of the family.

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.

Phonological awareness, reading skills, and vocabulary knowledge in children who use cochlear implants

In hearing children, reading skills have been found to be closely related to phonological awareness. We used several standardized tests to investigate the reading and phonological awareness skills of 27 deaf school-age children who were experienced cochlear implant users. Approximately two-thirds of the children performed at or above the level of their hearing peers on the phonological awareness and reading tasks. Reading scores were found to be strongly correlated with measures of phonological awareness. These correlations remained the same when we statistically controlled for potentially confounding demographic variables such as age at testing and speech perception skills. However, these correlations decreased even after we statistically controlled for vocabulary size. This finding suggests that lexicon size is a mediating factor in the relationship between the children's phonological awareness and reading skills, a finding that has also been reported for typically developing hearing children.

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

OBJECTIVES

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Inferior frontal gyrus activation predicts individual differences in perceptual learning of cochlear-implant simulations

This study investigated the neural plasticity associated with perceptual learning of a cochlear implant (CI) simulation. Normal-hearing listeners were trained with vocoded and spectrally shifted speech simulating a CI while cortical responses were measured with functional magnetic resonance imaging (fMRI). A condition in which the vocoded speech was spectrally inverted provided a control for learnability and adaptation. Behavioral measures showed considerable individual variability both in the ability to learn to understand the degraded speech, and in phonological working memory capacity. Neurally, left-lateralized regions in superior temporal sulcus and inferior frontal gyrus (IFG) were sensitive to the learnability of the simulations, but only the activity in prefrontal cortex correlated with interindividual variation in intelligibility scores and phonological working memory. A region in left angular gyrus (AG) showed an activation pattern that reflected learning over the course of the experiment, and covariation of activity in AG and IFG was modulated by the learnability of the stimuli. These results suggest that variation in listeners' ability to adjust to vocoded and spectrally shifted speech is partly reflected in differences in the recruitment of higher-level language processes in prefrontal cortex, and that this variability may further depend on functional links between the left inferior frontal gyrus and angular gyrus. Differences in the engagement of left inferior prefrontal cortex, and its covariation with posterior parietal areas, may thus underlie some of the variation in speech perception skills that have been observed in clinical populations of CI users.

Cued speech for enhancing speech perception and first language development of children with cochlear implants

Nearly 300 million people worldwide have moderate to profound hearing loss. Hearing impairment, if not adequately managed, has strong socioeconomic and affective impact on individuals. Cochlear implants have become the most effective vehicle for helping profoundly deaf children and adults to understand spoken language, to be sensitive to environmental sounds, and, to some extent, to listen to music. The auditory information delivered by the cochlear implant remains non-optimal for speech perception because it delivers a spectrally degraded signal and lacks some of the fine temporal acoustic structure. In this article, we discuss research revealing the multimodal nature of speech perception in normally-hearing individuals, with important inter-subject variability in the weighting of auditory or visual information. We also discuss how audio-visual training, via Cued Speech, can improve speech perception in cochlear implantees, particularly in noisy contexts. Cued Speech is a system that makes use of visual information from speechreading combined with hand shapes positioned in different places around the face in order to deliver completely unambiguous information about the syllables and the phonemes of spoken language. We support our view that exposure to Cued Speech before or after the implantation could be important in the aural rehabilitation process of cochlear implantees. We describe five lines of research that are converging to support the view that Cued Speech can enhance speech perception in individuals with cochlear implants.

Visual-motor integration skills of prelingually deaf children: implications for pediatric cochlear implantation

OBJECTIVE

To investigate visual-motor integration (VI) skills of prelingually deaf (PLD) children before and after cochlear implantation (CI) and investigate correlations with spoken-language and related processing measures.

DESIGN

Study 1 was a longitudinal study in which VI was tested preimplant. Study 2 was a cross sectional study of school-age children who used a CI for >2 years.

METHOD

In study 1, a standardized design-copying task was administered preimplant, and spoken-language data were obtained at intervals up to 4 years postimplantation. Analyses were conducted to determine if preimplant VI scores were predictive of various spoken-language measures. In study 2, standardized design copying and speeded maze tracing tasks were administered along with speech perception, vocabulary, and related processing measures.

RESULTS

Whereas preimplant VI scores for children in study 1 fell within the typical range based on age-equivalent norms, postimplant VI standard scores in study 2 were low compared to the normative sample. Postimplant VI scores were inversely related to age at implantation. Preimplant VI scores were robustly predictive of most, but not all, spoken-language outcome scores. Postimplant design copying scores were also correlated with spoken-language and related processing measures whereas maze-tracing scores were less robustly related to these measures.

CONCLUSIONS

Early auditory and linguistic experience may impact the development of VI skills. VI is a preimplant predictor of later spoken language outcomes. Design copying and speeded maze tracing tasks appear to tap different sets of cognitive resources in PLD children with CIs.

Nonword repetition with spectrally reduced speech: some developmental and clinical findings from pediatric cochlear implantation

Nonword repetition skills were examined in 24 pediatric cochlear implant (CI) users and 18 normal-hearing (NH) adult listeners listening through a CI simulator. Two separate groups of NH adult listeners assigned accuracy ratings to the nonword responses of the pediatric CI users and the NH adult speakers. Overall, the nonword repetitions of children using CIs were rated as more accurate than the nonword repetitions of the adults. The nonword repetition accuracy ratings from both groups of subjects were correlated with open- and closed-set word recognition scores and forward digit spans. Only the perceptual accuracy scores from pediatric CI users were correlated with measures of speech production accuracy. These results suggest that although the pediatric CI users had more experience and success in perceiving speech under degraded auditory conditions, developmental differences in their memory skills prevent them from performing as well on working memory tasks as mature listeners.

Non word Repetition and Reading Skills in Children Who Are Deaf and Have Cochlear Implants

Reading skills in hearing children are closely related to their phonological processing skills, often measured using a nonword repetition task in which a child relies on abstract phonological representations in order to decompose, encode, rehearse in working memory and reproduce novel phonological patterns. In the present study of children who are deaf and have cochlear implants, we found that nonword repetition performance was significantly related to nonword reading, single word reading and sentence comprehension. Communication mode and nonverbal IQ were also found to be correlated with nonword repetition and reading skills. A measure of the children's lexical diversity, derived from an oral language sample, was found to be a mediating factor in the relationship between nonword repetition and reading skills. Taken together, the present findings suggest that the construction of robust phonological representations and phonological processing skills may be important contributors to the development of reading in children who are deaf and use cochlear implants.

Effects of a cochlear implant simulation on immediate memory in normal-hearing adults

This study assessed the effects of stimulus misidentification and memory processing errors on immediate memory span in 25 normal-hearing adults exposed to degraded auditory input simulating signals provided by a cochlear implant. The identification accuracy of degraded digits in isolation was measured before digit span testing. Forward and backward digit spans were shorter when digits were degraded than when they were normal. Participants' normal digit spans and their accuracy in identifying isolated digits were used to predict digit spans in the degraded speech condition. The observed digit spans in degraded conditions did not differ significantly from predicted digit spans. This suggests that the decrease in memory span is related primarily to misidentification of digits rather than memory processing errors related to cognitive load. These findings provide complementary information to earlier research on auditory memory span of listeners exposed to degraded speech either experimentally or as a consequence of a hearing-impairment.

Word Learning in Children Following Cochlear Implantation

An experimental procedure was developed to investigate word-learning skills of children who use cochlear implants (CIs). Using interactive play scenarios, 2- to 5-year olds were presented with sets of objects (Beanie Baby stuffed animals) and words for their names that corresponded to salient perceptual attributes (e.g., "horns" for a goat). Their knowledge of the word-object associations was measured immediately after exposure and then following a 2-hour delay. Children who use cochlear implants performed more poorly than age-matched children with typical hearing both receptively and expressively. Both groups of children showed retention of the word-object associations in the delayed testing conditions for words that were previously known. Our findings suggest that although pediatric CI users may have impaired phonological processing skills, their long-term memory for familiar words may be similar to children with typical hearing. Further, the methods that developed in this study should be useful for investigating other aspects of word learning in children who use CIs.