Assessing consonant production in children with cochlear implants.

OBJECTIVE: The objective of this study was to investigate the development of consonant inventory and accuracy in pediatric cochlear implant (CI) recipients and compare their performance to typical hearing (TH) children. METHODS: One hundred and twenty nine children with CIs, implanted between 6-38 months of age, and 30 age-matched children with TH participated in this study. Spontaneous speech samples were collected at 3.5 and 4.5 years chronological age and the first 100 different words spoken by each participant were transcribed. Two consonant production measures were subsequently calculated to assess consonant acquisition and mastery. The percentage of Consonants Correct (CC) was used for measuring accuracy and Consonant Diversity (CD), an inventory measure, was used to identify the number of different consonants spoken by each participant. Repeated measures analyses of variance were conducted to examine the differences in consonant production scores based on presence of CI (participants with CI versus typical hearing (TH) participants), and chronological age at data collection (3.5 years versus 4.5 years). RESULTS: CI recipients displayed lower consonant production scores compared to TH children. Children with the most device experience (32-38 months at 3.5 years) performed on par with their TH peers. CONCLUSIONS: The two measures used in this study together appear capable of comprehensively describing the changes in consonant production skills of children. Results from this study indicate that while most CI participants display lower scores compared to TH children, many of the CI users are able to produce speech sounds on par with TH children.

Sensitivity of expressive linguistic domains to surgery age and audibility of speech in preschoolers with cochlear implants.

OBJECTIVES: To determine whether relative delays among domains exist in the conversational use of vocabulary, syntax, and morphology by children with cochlear implants (CIs) and whether these were differentially affected by age of implantation (AOI) and the audibility of speech. METHODS: Participants in this short-term longitudinal study were 126 children with AOI of 6-38 months and a matched group of 30 children without hearing loss. Language samples of the same children at ages 3.5 and 4.5 were analyzed for the breadth of vocabulary and bound morphemes used, and sentence length. RESULTS: At both test ages, expressive language domains were delayed equally. Higher performance across domains was independently associated with younger AOI and better pre-implant-aided thresholds. No domain was affected differently by very early implantation, but bound morpheme breadth was associated with better CI-aided thresholds. Between 63 and 78% of children with AOI of 6-11 months scored close to hearing age-mates by 4.5, a level achieved by fewer than 25% of those with AOI of 19-24 months or later ages. DISCUSSION: Previous studies indicated greater language delays in the areas of morphology and syntax than those of vocabulary, with the earliest ages of implantation conferring the greatest benefit to those domains. The current design addressed inconsistency across studies in modes of communication used, presence/absence of other disabilities, and differences in language domains chosen as outcome measures. CONCLUSIONS: Linguistic domains benefitted equally from early implantation, regardless of the duration of auditory stimulation. Better pre-CI-aided hearing often compensated for later AOI. Bound morpheme use was greater with better CI-aided thresholds.

Persistent Language Delay Versus Late Language Emergence in Children With Early Cochlear Implantation.

PURPOSE: The purpose of the present investigation is to differentiate children using cochlear implants (CIs) who did or did not achieve age-appropriate language scores by midelementary grades and to identify risk factors for persistent language delay following early cochlear implantation. MATERIALS AND METHOD: Children receiving unilateral CIs at young ages (12-38 months) were tested longitudinally and classified with normal language emergence (n = 19), late language emergence (n = 22), or persistent language delay (n = 19) on the basis of their test scores at 4.5 and 10.5 years of age. Relative effects of demographic, audiological, linguistic, and academic characteristics on language emergence were determined. RESULTS: Age at CI was associated with normal language emergence but did not differentiate late emergence from persistent delay. Children with persistent delay were more likely to use left-ear implants and older speech processor technology. They experienced higher aided thresholds and lower speech perception scores. Persistent delay was foreshadowed by low morphosyntactic and phonological diversity in preschool. Logistic regression analysis predicted normal language emergence with 84% accuracy and persistent language delay with 74% accuracy. CONCLUSION: CI characteristics had a strong effect on persistent versus resolving language delay, suggesting that right-ear (or bilateral) devices, technology upgrades, and improved audibility may positively influence long-term language outcomes.

The effects of audibility and novel word learning ability on vocabulary level in children with cochlear implants.

OBJECTIVES: A novel word learning (NWL) paradigm was used to explore underlying phonological and cognitive mechanisms responsible for delayed vocabulary level in children with cochlear implants (CIs). METHODS: One hundred and one children using CIs, 6-12 years old, were tested along with 47 children with normal hearing (NH). Tests of NWL, receptive vocabulary, and speech perception at 2 loudness levels were administered to children with CIs. Those with NH completed the NWL task and a receptive vocabulary test. CI participants with good audibility (GA) versus poor audibility (PA) were compared on all measures. Analysis of variance was used to compare performance across the children with NH and the two groups of children with CIs. Multiple regression analysis was employed to identify independent predictors of vocabulary outcomes. RESULTS: Children with CIs in the GA group scored higher in receptive vocabulary and NWL than children in the PA group, although they did not reach NH levels. CI-aided pure tone threshold and performance on the NWL task predicted independent variance in vocabulary after accounting for other known predictors. DISCUSSION: Acquiring spoken vocabulary is facilitated by GA with a CI and phonological learning and memory skills. Children with CIs did not learn novel words at the same rate or achieve the same receptive vocabulary levels as their NH peers. Maximizing audibility for the perception of speech and direct instruction of new vocabulary may be necessary for children with CIs to reach levels seen in peers with NH.

Emergence of speech sounds between 7 and 24 months of cochlear implant use.

OBJECTIVES: To investigate the process of speech development in five 42-month-old children with profound deafness who received cochlear implants (CIs) between 19 and 36 months of age and five normal hearing (NH) age mates. METHODS: Conversational samples were collected and transcribed. Sounds produced correctly within meaningful words (target sounds) and recognizable sounds produced in spontaneous productions (target-less sounds) were analyzed for all 10 children. RESULTS: Revealed that there was overlap in the total number of vowels and consonants produced by the two groups. The differences between the two groups were more evident in the target condition, whereas the two groups were more similar in the target-less condition. DISCUSSION: The similarities documented in the target-less repertoire of CI and NH children underscore the importance of examining the emerging sound system to predict the end-point sound system in children with CIs. Using target and target-less speech sound comparisons offers a supplementary view of the emergent process of speech sound development and is a valid method of analysis. Results suggest that early implantation may help some children with profound deafness develop speech sounds in a manner similar to NH age mates.

Interdependence of linguistic and indexical speech perception skills in school-age children with early cochlear implantation.

OBJECTIVES: This study documented the ability of experienced pediatric cochlear implant (CI) users to perceive linguistic properties (what is said) and indexical attributes (emotional intent and talker identity) of speech, and examined the extent to which linguistic (LSP) and indexical (ISP) perception skills are related. Preimplant-aided hearing, age at implantation, speech processor technology, CI-aided thresholds, sequential bilateral cochlear implantation, and academic integration with hearing age-mates were examined for their possible relationships to both LSP and ISP skills. DESIGN: Sixty 9- to 12-year olds, first implanted at an early age (12 to 38 months), participated in a comprehensive test battery that included the following LSP skills: (1) recognition of monosyllabic words at loud and soft levels, (2) repetition of phonemes and suprasegmental features from nonwords, and (3) recognition of key words from sentences presented within a noise background, and the following ISP skills: (1) discrimination of across-gender and within-gender (female) talkers and (2) identification and discrimination of emotional content from spoken sentences. A group of 30 age-matched children without hearing loss completed the nonword repetition, and talker- and emotion-perception tasks for comparison. RESULTS: Word-recognition scores decreased with signal level from a mean of 77% correct at 70 dB SPL to 52% at 50 dB SPL. On average, CI users recognized 50% of key words presented in sentences that were 9.8 dB above background noise. Phonetic properties were repeated from nonword stimuli at about the same level of accuracy as suprasegmental attributes (70 and 75%, respectively). The majority of CI users identified emotional content and differentiated talkers significantly above chance levels. Scores on LSP and ISP measures were combined into separate principal component scores and these components were highly correlated (r = 0.76). Both LSP and ISP component scores were higher for children who received a CI at the youngest ages, upgraded to more recent CI technology and had lower CI-aided thresholds. Higher scores, for both LSP and ISP components, were also associated with higher language levels and mainstreaming at younger ages. Higher ISP scores were associated with better social skills. CONCLUSIONS: Results strongly support a link between indexical and linguistic properties in perceptual analysis of speech. These two channels of information appear to be processed together in parallel by the auditory system and are inseparable in perception. Better speech performance, for both linguistic and indexical perception, is associated with younger age at implantation and use of more recent speech processor technology. Children with better speech perception demonstrated better spoken language, earlier academic mainstreaming, and placement in more typically sized classrooms (i.e., >20 students). Well-developed social skills were more highly associated with the ability to discriminate the nuances of talker identity and emotion than with the ability to recognize words and sentences through listening. The extent to which early cochlear implantation enabled these early-implanted children to make use of both linguistic and indexical properties of speech influenced not only their development of spoken language, but also their ability to function successfully in a hearing world.

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.

Expected test scores for preschoolers with a cochlear implant who use spoken language.

PURPOSE: The major purpose of this study was to provide information about expected spoken language skills of preschool-age children who are deaf and who use a cochlear implant. A goal was to provide "benchmarks" against which those skills could be compared, for a given age at implantation. We also examined whether parent-completed checklists of children's language were correlated with results of standardized language tests and whether scores increased linearly with decreasing age of implantation and increasing duration of cochlear implant use. METHOD: Participants were a nationwide sample of 76 children who were deaf and orally educated and who received an implant by 38 months of age. Formal language tests were administered at age 4.5 years. The MacArthur-Bates Communicative Development Inventories (CDI) instrument was completed by parents when children were ages 3.5 and 4.5 years. RESULTS: Based on regression analyses, expected scores for each age at implant were provided for 2 commonly administered language tests at 4.5 years of age and CDI subscale scores at 3.5 and 4.5 years. Concurrent test scores were significantly correlated on all measures. A linear relation was found that predicted increasing test scores with younger ages at implantation for all scales administered. CONCLUSIONS: While the expected scores reported here should not be considered as normative data, they are benchmarks that may be useful for evaluating spoken language progress of children with cochlear implants who are enrolled in spoken language-based programs.

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

PURPOSE: The authors examined the benefits of younger cochlear implantation, longer cochlear implant use, and greater pre-implant aided hearing to spoken language at 3.5 and 4.5 years of age. METHOD: Language samples were obtained at ages 3.5 and 4.5 years from 76 children who received an implant by their 3rd birthday. Hierarchical linear modeling was used to identify characteristics associated with spoken language outcomes at the 2 test ages. The Preschool Language Scale (I. L. Zimmerman, V. G. Steiner, & R. E. Pond, 1992) was used to compare the participants' skills with those of hearing age-mates at age 4.5 years. RESULTS: Expected language scores increased with younger age at implant and lower pre-implant thresholds, even when compared at the same duration of implant use. Expected Preschool Language Scale scores of the children who received the implant at the youngest ages reached those of hearing age-mates by 4.5 years, but those children implanted after 24 months of age did not catch up with hearing peers. CONCLUSION: Children who received a cochlear implant before a substantial delay in spoken language developed (i.e., between 12 and 16 months) were more likely to achieve age-appropriate spoken language. These results favor cochlear implantation before 24 months of age, especially for children with aided pure-tone average thresholds greater than 65 dB prior to surgery.

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.

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

OBJECTIVE: By age 3, typically developing children have achieved extensive vocabulary and syntax skills that facilitate both cognitive and social development. Substantial delays in spoken language acquisition have been documented for children with severe to profound deafness, even those with auditory oral training and early hearing aid use. This study documents the spoken language skills achieved by orally educated 3-yr-olds whose profound hearing loss was identified and hearing aids fitted between 1 and 30 mo of age and who received a cochlear implant between 12 and 38 mo of age. The purpose of the analysis was to examine the effects of age, duration, and type of early auditory experience on spoken language competence at age 3.5 yr. DESIGN: The spoken language skills of 76 children who had used a cochlear implant for at least 7 mo were evaluated via standardized 30-minute language sample analysis, a parent-completed vocabulary checklist, and a teacher language-rating scale. The children were recruited from and enrolled in oral education programs or therapy practices across the United States. Inclusion criteria included presumed deaf since birth, English the primary language of the home, no other known conditions that interfere with speech/language development, enrolled in programs using oral education methods, and no known problems with the cochlear implant lasting more than 30 days. RESULTS: Strong correlations were obtained among all language measures. Therefore, principal components analysis was used to derive a single Language Factor score for each child. A number of possible predictors of language outcome were examined, including age at identification and intervention with a hearing aid, duration of use of a hearing aid, pre-implant pure-tone average (PTA) threshold with a hearing aid, PTA threshold with a cochlear implant, and duration of use of a cochlear implant/age at implantation (the last two variables were practically identical because all children were tested between 40 and 44 mo of age). Examination of the independent influence of these predictors through multiple regression analysis revealed that pre-implant-aided PTA threshold and duration of cochlear implant use (i.e., age at implant) accounted for 58% of the variance in Language Factor scores. A significant negative coefficient associated with pre-implant-aided threshold indicated that children with poorer hearing before implantation exhibited poorer language skills at age 3.5 yr. Likewise, a strong positive coefficient associated with duration of implant use indicated that children who had used their implant for a longer period of time (i.e., who were implanted at an earlier age) exhibited better language at age 3.5 yr. Age at identification and amplification was unrelated to language outcome, as was aided threshold with the cochlear implant. A significant quadratic trend in the relation between duration of implant use and language score revealed a steady increase in language skill (at age 3.5 yr) for each additional month of use of a cochlear implant after the first 12 mo of implant use. The advantage to language of longer implant use became more pronounced over time. CONCLUSIONS: Longer use of a cochlear implant in infancy and very early childhood dramatically affects the amount of spoken language exhibited by 3-yr-old, profoundly deaf children. In this sample, the amount of pre-implant intervention with a hearing aid was not related to language outcome at 3.5 yr of age. Rather, it was cochlear implantation at a younger age that served to promote spoken language competence. The previously identified language-facilitating factors of early identification of hearing impairment and early educational intervention may not be sufficient for optimizing spoken language of profoundly deaf children unless it leads to early cochlear implantation.

Language skills of children with early cochlear implantation.

OBJECTIVE: This study investigated factors contributing to the comprehension and production of English language by children with prelingual deafness after 4 to 7 yr of multichannel cochlear implant use. The analysis controlled for the effects of child and family characteristics so that educational factors most conducive to maximum implant benefit could be identified. DESIGN: A battery of language tests were administered to 181 8- and 9 yr-old children from across the United States and Canada who received a cochlear implant by age 5. Tests of comprehension, verbal reasoning, narrative ability and spontaneous language production were administered either in speech and sign or in the child's preferred communication mode. These constituted the Total Language measures. Spoken Language measures were derived from a speech-only language sample. Type and amount of educational intervention since implantation constituted the independent variables. Characteristics of the child and the family were considered intervening variables. A series of multiple regression analyses determined the amount of variance in Total Language and Spoken Language ability accounted for by the intervening variables and the amount of additional variance attributable to the independent variables. RESULTS: More than half of the children (with performance intelligence quotients in the average range) exhibited language skills that were similar to those of hearing 8 to 9 yr olds on measures of verbal reasoning, narrative ability, utterance length, and lexical diversity. Significant predictors of language ability were similar for Total and for Spoken Language outcomes and included greater nonverbal intelligence, smaller family size, higher socio-economic status and female gender. Age at receiving an implant did not affect language outcome. After the variance due to these variables was controlled, the primary rehabilitative factors associated with linguistic outcome were amount of mainstream class placement and an educational emphasis on speech and auditory skills. CONCLUSIONS: Use of a cochlear implant has had a dramatic impact on the linguistic competence of profoundly hearing-impaired children. More than half of the children in this sample with average learning ability produced and understood English language at a level comparable with that of their hearing age mates. Such mature language outcomes were not typical of children with profound hearing loss who used hearing aids. Use of a visual (i.e., sign) language system did not provide the linguistic advantage that had been anticipated. Children educated without use of sign exhibited a significant advantage in their use of narratives, the breadth of their vocabulary, in their use of bound morphemes, in the length of their utterances and in the complexity of the syntax used in their spontaneous language. An oral educational focus provided a significant advantage for both spoken and total language skills.

Personal, social, and family adjustment in school-aged children with a cochlear implant.

OBJECTIVE: The present study sought to document the psycho-social adjustment of 181 school-aged deaf children who have had a cochlear implant for 4 or more yr and to examine parental satisfaction with the outcome of the implantation process on their child's life and on their family's life in general. DESIGN: Three measures were employed. One measure was a self-report instrument designed to assess perceived self-competence in children, one was a rating scale completed by parents that sought to assess the degree of their child's personal-social adjustment, and the third was a questionnaire given to parents on which they rated their satisfaction with aspects of the cochlear implant and how it had affected their child's functioning within the context of family life. RESULTS: Children generally perceived themselves (and parents perceived their children) as being competent and well adjusted in most aspects of daily life. Parents expressed a generally positive view of cochlear implantation and its effects on family life. None of the social-emotional adjustment measures was significantly related to the speech perception, speech production or language skills the child achieved postimplant. However, the parents' satisfaction with their child's cochlear implantation was significantly related to their child's speech and language achievements. On the perceived self-competence instrument, younger children and those with longer use of the updated SPEAK speech processor gave themselves higher ratings. Parent ratings of their child's adjustment tended to be higher for girls than for boys, for more rather than less intelligent children, and for children enrolled in private as opposed to public school settings. CONCLUSIONS: Deaf children who have used a cochlear implant for 4 to 6 yr report that they are coping successfully with the demands of their social and school environment, regardless of their speech and language achievements after implantation. Parents' ratings indicate that these children are emotionally and socially well adjusted and that they have benefited from cochlear implantation. To the extent that the children and their parents accurately reported their attitudes and feelings regarding their experiences at home and at school, these results represent an impressive level of personal and social adjustment when compared with previous literature on adjustment problems in deaf children. The extent to which these results are associated with cochlear implantation has not been determined and awaits comparative data from children without implants.

Hearing Status, Language Modality, and Young Children's Communicative and Linguistic Behavior.

This study examined early pragmatic skill development in a group of 38 children with severe or profound hearing loss between 1 and 4 years of age who were enrolled in a simultaneous communication (SC) approach to language learning. Both their use of intentionally communicative acts and their use of language were studied in an analysis of 30-min play sessions between a child and the primary caregiver. Results were compared with previously published data from two age-matched groups: 38 deaf children who were enrolled in oral communication (OC) programs and 84 normally hearing (NH) children. All groups showed a significant improvement with age in the communicative behaviors measured; therefore, the overall trend was toward growth-in all age groups-even when the rates of growth differed. By age 3 years, a pattern of communicative function use had emerged in all three groups. Patterns exhibited by deaf children in the SC and OC groups were similar to each other and to younger NH children but dissimilar to NH age mates. Although the use of signed input by normally hearing parents and teachers did not serve to ameliorate the profound effects of hearing loss on communication development in SC children, it did provide some early advantages. The children in SC groups did not exhibit an advantage over children in OC groups in their overall frequency of communication or the breadth of their vocabulary but they began using words earlier and used mature communicative functions significantly more often. Although children in the OC groups did not exhibit a significant advantage in the overall amount of speech used, they showed an advantage in the breadth of their spoken vocabulary in a conversational setting. Implications for early intervention programming are discussed.

Rehabilitation factors contributing to implant benefit in children.

This study was performed to investigate factors contributing to auditory, speech, language, and reading outcomes after 4 to 6 years of multichannel cochlear implant use in children with prelingual deafness. The analysis controlled for the effects of child, family, and implant characteristics so that the educational factors most conducive to maximum implant benefit could be identified. We tested 136 children from across the United States and Canada. All were 8 or 9 years of age, had an onset of deafness before 3 years of age, underwent implantation by 5 years of age, and resided in a monolingual English-speaking home environment. Characteristics of the child and the family (primarily nonverbal IQ) accounted for approximately 20% of the variance in outcome after implantation. An additional 24% was accounted for by implant characteristics and 12% by educational variables, particularly communication mode. Oral education appears to be an important educational choice for children who have undergone cochlear implantation before 5 years of age.