Syntagmatic and paradigmatic development of cochlear implanted children in comparison with normally hearing peers up to age 7

Processing of Plural Marking in Nouns by German-Speaking Children With Normal Hearing and Children With Cochlear Implants: An Eye-Tracking Study

PURPOSE

Our goal is to understand how the different types of plural marking are understood and processed by children with cochlear implants (CIs): (a) how does salience affect the processing of plural marking, (b) how is this processing affected by the incomplete signal provided by the CIs, and (c) is it linked to individual factors such as chronological age, vocabulary development, and phonological working memory?

METHOD

Sixteen children with CIs and 30 age-matched children with normal hearing (NH) participated in an eye-tracking study. Their task was to choose the corresponding picture to an auditorily presented singular or plural noun. Accuracy, reaction time, and gaze fixation were measured and analyzed with mixed-effect models.

RESULTS

Group differences were found in accuracy but not in reaction time or gaze fixation. Plural processing is qualitatively similar in children with CIs and children with NH, with more difficulties in processing plurals involving stem-vowel changes and less with those involving suffixes. Age effects indicate that processing abilities still evolve between 5 and 11 years, and processing is further linked to lexical development.

CONCLUSIONS

Our results indicate that early implantation seems to be beneficial for the acquisition of plural as indicated by very small between-group differences in processing and comprehension. Processing is furthermore affected by the type of material (i.e., phonetic, phonological, or morphological) used to mark plural and less so by their segmental salience. Our study emphasizes the need to take into account the form of the linguistic material in future investigations at higher levels of processing.

Early grammar-building in French-speaking deaf children with cochlear implants: A follow-up corpus study

BACKGROUND

One of the most consistent findings reported in the paediatric cochlear implant (CI) literature is the heterogeneity of language performance observed more in grammatical morphology than in lexicon or pragmatics. As most of the corpus studies addressing these issues have been conducted in English, it is unclear whether their results can be generalized to other languages. In particular, little is known about languages known for their grammatical complexity, such as French.

AIMS

The aim of this corpus study was to compare the productive use of function words (FWs) and some agreement features (AGRs) in children with CIs and children with typical development (TD) matched for mean length of utterance in words (MLU_words ), a general index of grammatical complexity, and auditory experience, as measured by hearing age (HA) and chronological age (CA), respectively.

METHODS & PROCEDURES

Natural speech samples from 116 monolingual French-speaking children, including 40 children with CIs followed longitudinally and 76 TD children, were collected. FWs and AGRs were analysed using a Part of Speech Tagger (POS-T) from the Child Language Data Exchange System (CHILDES).

OUTCOMES & RESULTS

The two groups differed by 3 years for HA and CA. No effect of family socio-economic status (SES) was found in the CI group. Stepwise regression analyses showed that the two groups did not share the same predictors of MLU_words : plurals and determiners predicted MLU_words in children with CIs, at 2 and 3 years of HA, whereas feminine markers and subject-pronouns were found to best predict MLU_words in TD children at 2 and 3 years of CA. Structural equation models (SEMs), a combination of confirmatory factor analysis (CFA) and path analysis, yielded a different hierarchical structure of grammatical relations (GRs). Selective difficulties affecting verbal clitics and other pronominal forms were found specifically in the CI group (object-pronouns, reflexive, relative and past participles). Dependency grammar analysis confirmed these contrasting developmental profiles in multiword utterances, such as preposition/nouns, subject/verbs, and verb/determiner/nouns.

CONCLUSIONS & IMPLICATIONS

Atypical grammatical patterns in children with CIs reflect a specific architecture of syntactic dependencies of FWs underpinning morphological complexity and syntactic connectivity. Clinical implications are discussed for assessment and intervention planning.

WHAT THIS PAPER ADDS

What is already known on this subject The productive use of FWs has been identified as a particular area of weakness in children with CIs compared with TD children. In addition, heterogenous grammatical performance has often been found after 1-3 years of CI use, regardless of demographic factors such as age at implantation, duration of deafness or SES. What this paper adds to existing knowledge Assessing the early building of FWs and AGRs in children with CIs helps to understand the syntactic complexity and hierarchical structure of their language. Since most corpus studies on grammatical morphology have been conducted in English, it is not clear whether their difficulties can be generalized to other languages. The French language has a system of FWs and inflections that determine the morphophonological properties of nominal and verbal forms. Early grammar learning in children with CIs born with profound deafness were compared with the two groups of TD children matched both for duration of auditory experience (i.e., HA of CI children, CA of TD children) and for MLU_words . We found a similar profile between groups at 2 years but not at 3 years for HA and CA. The two groups do not share the same predictors of MLU_words : namely, plurals and determiners for CI children versus feminine markers and subject pronouns for TD children. They show a different syntactic organization of GRs. Children with CIs struggle with selective difficulties affecting verbal clitics and pronominal forms (object-pronouns, reflexive, relative and past participles). Consistent with theories of morphophonological richness and syntactic connectivity, our results support the distributional learning hypothesis of language acquisition that infants and toddlers are sensitive to FWs and AGRs at an early age. Specific components of syntactic organization are disrupted in children with CIs. What are the potential or actual clinical implications of this work? This work has potential clinical implications because it unravels the limitations of morphophonological processing in children with CIs. Its results highlight a specific difficulty in learning FWs and AGRs in a verbal inflectional morphology context.

Spontaneous speech intelligibility: early cochlear implanted children versus their normally hearing peers at seven years of age

Speaking intelligibly is an important achievement in children's language development. How far do congenitally severe-to-profound hearing-impaired children who received a cochlear implant (CI) in the first two years of their life advance on the path to intelligibility in comparison to children with typical hearing (NH)? Spontaneous speech samples of children with CI and children with NH were orthographically transcribed by naïve transcribers. The entropy of the transcriptions was computed to analyze their degree of uniformity. The same samples were also rated on a continuous rating scale by another group of adult listeners. The transcriptions of the NH children's speech were more uniform, i.e., had significantly lower entropy, than those of the CI children, suggesting that the latter group displayed lower intelligibility. This was confirmed by the ratings on the continuous scale. Despite the relatively restricted age ranges, older children reached better intelligibility scores in both groups.

Tailoring the Input to Children's Needs: The Use of Fine Lexical Tuning in Speech Directed to Normally Hearing Children and Children With Cochlear Implants

Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed speech (IDS) addressed to congenitally deaf infants who received a cochlear implant (CI) early in life (<2 years of age) in comparison with children with normal hearing (NH). The longitudinal pattern of parents' utterance length in the initial stages of the child's lexical development was examined. Parents' utterances containing the words the children eventually acquired in the earliest developmental stages were selected and their MLU (Mean Length of Utterance) was measured.

Method: Transcriptions of monthly recordings of spontaneous interactions of 10 CI children and 30 NH children with their parents were analyzed. The children with CI were followed from the moment their device was switched on, and the NH children from the age of 6 months onwards. A total of 57,846 utterances of parents of CI children and 149,468 utterances of parents of NH children were analyzed.

Results: IDS addressed to children with NH and children with CI exhibits fine lexical tuning: parents adjust the MLU of the utterances that contain the words that children are on the verge of producing themselves. More specifically, the parents' mean length of those utterances decreased in relation to the point when the children began using the item. Consequently, the number of occurrences in isolation of the lexical item increased. The speech addressed to all the children exhibited this phenomenon, but it was significantly more strongly present in speech addressed to the children with CI.

Conclusions: The speech addressed to children with NH and CI is characterized by fine lexical tuning and a high incidence of single-word utterances in the period leading up to the children's first use of words in speech production. Notwithstanding striking commonalities, IDS addressed to children with a hearing impairment is markedly different, which suggests that parents take this specific character of the children into account.

A comparison of morpho-syntactic abilities in deaf children with cochlear implant and 5-year-old normal-hearing children

INTRODUCTION

Children with cochlear implants (CIs) have problems in morpho-syntactic abilities more than other language skills. The current study was aimed to evaluate the language samples of children with CIs by using a numerical measurement tool, Persian developmental sentence scoring (PDSS).

METHOD

In this cross-sectional, descriptive, analytical study, 33 children (22 children with CIs and 11 with normal hearing) were recruited. Language samples of the children were recorded during the description of pictures. The PDSS was used as a reliable numerical measurement tool for analyzing the first 100 consecutive intelligible utterances.

RESULTS

We found a significant difference in the mean PDSS total scores (p = 0.0001) between the normal-hearing children and deaf children using CIs for 5 years. Similarly, the results revealed a significant difference in the mean PDSS total scores (p = 0.0001) between the normal-hearing children and 5-year-old deaf children with CIs. There was no significant difference in the mean PDSS total scores between the two groups of children with CIs.

CONCLUSION

Children with CIs can form simple sentences but probably exhibit poor abilities for using complex sentences and essential morphology items.

Auditory Environment Across the Life Span of Cochlear Implant Users: Insights From Data Logging

PURPOSE

We describe the natural auditory environment of people with cochlear implants (CIs), how it changes across the life span, and how it varies between individuals.

METHOD

We performed a retrospective cross-sectional analysis of Cochlear Nucleus 6 CI sound-processor data logs. The logs were obtained from 1,501 people with CIs (ages 0-96 years). They covered over 2.4 million hr of implant use and indicated how much time the CI users had spent in various acoustical environments. We investigated exposure to spoken language, noise, music, and quiet, and analyzed variation between age groups, users, and countries.

RESULTS

CI users spent a substantial part of their daily life in noisy environments. As a consequence, most speech was presented in background noise. We found significant differences between age groups for all auditory scenes. Yet even within the same age group and country, variability between individuals was substantial.

CONCLUSIONS

Regardless of their age, people with CIs face challenging acoustical environments in their daily life. Our results underline the importance of supporting them with assistive listening technology. Moreover, we found large differences between individuals' auditory diets that might contribute to differences in rehabilitation outcomes. Their causes and effects should be investigated further.

Language skills and phonological awareness in children with cochlear implants and normal hearing

OBJECTIVES

Early auditory experience plays a major role in language acquisition. Linguistic and metalinguistic abilities of children aged 5-5.5 years with cochlear implants (CIs) were compared to age-matched children with normal hearing (NH) to investigate the effect of hearing on development of these two skills.

METHODS

Eighteen children with NH and 18 children with CIs took part in the study. The Test of Language Development-Primary, third edition, was used to assess language and metalinguistic skills by assessment of phonological awareness (PA). Language skills and PA were then compared between groups. Hierarchical linear regression was conducted to determine whether the language skills explained the unique variance in PA.

RESULTS

There were significant differences between children with NH and those with CIs for language skills and PA (p≤0.001). All language skills (semantics, syntax, listening, spoken language, organizing, and speaking) were uniquely predictive of PA outcome in the CI children. Linear combinations of listening and semantics and listening, semantics, and syntax correlated significantly with PA.

CONCLUSION

The results show that children with CIs may have trouble with language skills and PA. Listening, semantics, and syntax, among other skills, are significant indicators of the variance in PA for children with CIs.

The Perception of Stress Pattern in Young Cochlear Implanted Children: An EEG Study

Children with sensorineural hearing loss may (re)gain hearing with a cochlear implant—a device that transforms sounds into electric pulses and bypasses the dysfunctioning inner ear by stimulating the auditory nerve directly with an electrode array. Many implanted children master the acquisition of spoken language successfully, yet we still have little knowledge of the actual input they receive with the implant and specifically which language sensitive cues they hear. This would be important however, both for understanding the flexibility of the auditory system when presented with stimuli after a (life-) long phase of deprivation and for planning therapeutic intervention. In rhythmic languages the general stress pattern conveys important information about word boundaries. Infant language acquisition relies on such cues and can be severely hampered when this information is missing, as seen for dyslexic children and children with specific language impairment. Here we ask whether children with a cochlear implant perceive differences in stress patterns during their language acquisition phase and if they do, whether it is present directly following implant stimulation or if and how much time is needed for the auditory system to adapt to the new sensory modality. We performed a longitudinal ERP study, testing in bimonthly intervals the stress pattern perception of 17 young hearing impaired children (age range: 9–50 months; mean: 22 months) during their first 6 months of implant use. An additional session before the implantation served as control baseline. During a session they passively listened to an oddball paradigm featuring the disyllable “baba,” which was stressed either on the first or second syllable (trochaic vs. iambic stress pattern). A group of age-matched normal hearing children participated as controls. Our results show, that within the first 6 months of implant use the implanted children develop a negative mismatch response for iambic but not for trochaic deviants, thus showing the same result as the normal hearing controls. Even congenitally deaf children show the same developing pattern. We therefore conclude (a) that young implanted children have early access to stress pattern information and (b) that they develop ERP responses similar to those of normal hearing children.