Phonological processing skills and its relevance to receptive vocabulary development in children with early cochlear implantation

Two are better than one: Differences in cortical EEG patterns during auditory and visual verbal working memory processing between Unilateral and Bilateral Cochlear Implanted children

Despite the proven effectiveness of cochlear implant (CI) in the hearing restoration of deaf or hard-of-hearing (DHH) children, to date, extreme variability in verbal working memory (VWM) abilities is observed in both unilateral and bilateral CI user children (CIs). Although clinical experience has long observed deficits in this fundamental executive function in CIs, the cause to date is still unknown. Here, we have set out to investigate differences in brain functioning regarding the impact of monaural and binaural listening in CIs compared with normal hearing (NH) peers during a three-level difficulty n-back task undertaken in two sensory modalities (auditory and visual). The objective of this pioneering study was to identify electroencephalographic (EEG) marker pattern differences in visual and auditory VWM performances in CIs compared to NH peers and possible differences between unilateral cochlear implant (UCI) and bilateral cochlear implant (BCI) users. The main results revealed differences in theta and gamma EEG bands. Compared with hearing controls and BCIs, UCIs showed hypoactivation of theta in the frontal area during the most complex condition of the auditory task and a correlation of the same activation with VWM performance. Hypoactivation in theta was also observed, again for UCIs, in the left hemisphere when compared to BCIs and in the gamma band in UCIs compared to both BCIs and NHs. For the latter two, a correlation was found between left hemispheric gamma oscillation and performance in the audio task. These findings, discussed in the light of recent research, suggest that unilateral CI is deficient in supporting auditory VWM in DHH. At the same time, bilateral CI would allow the DHH child to approach the VWM benchmark for NH children. The present study suggests the possible effectiveness of EEG in supporting, through a targeted approach, the diagnosis and rehabilitation of VWM in DHH children.

Executive functions in preschool and school-age cochlear implant users: do they differ from their hearing peers? A systematic review and meta-analysis

PURPOSE

Executive functions (EF) play a fundamental role in planning and executing goal-driven behaviours. The purpose of this systematic review and meta-analysis was to investigate EF skills mastered by preschool/school-age cochlear implanted children (CIC) without morpho-functional abnormalities and to compare their outcomes with typically hearing children (THC).

METHODS

Bibliographic search for observational studies of any language/date up to 16 December 2022 was performed with the following electronic databases: PubMed, Scopus, and Web of Science. After removal of duplicates, 2442 records were subjected to a three-stage screening process and 83 potentially eligible articles were identified. A total of 15 studies was included in the final analysis: 9 articles directly meeting the eligibility criteria plus 6 more studies thanks to the authors sharing their data set, specifically for participants who met present inclusion criteria.

RESULTS

Meta-analysis showed a statistically significant difference only for verbal short-term memory, whereas group differences for visuospatial short-term memory and verbal/visuospatial working memory were not significant. For fluency skills, meta-analysis revealed statistical significance for the semantic fluency task but not for the rapid naming test. Qualitative analysis reflected group similarities in flexibility but CIC's difficulties in auditory attention/planning skills. Controversial findings for inhibitory control skills were observed.

CONCLUSIONS

EF performance comparisons between CIC and THC show inter-skill and inter-test variances. Due to the paucity of existing studies, present findings should be interpreted with caution. Future research in this domain is strongly recommended.

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.

Is Early Cochlear Implantation Leads to Better Speech and Language Outcomes?

A cochlear implant is an electronic sensory system that converts mechanical energy into coded electrical signals that directly activate the auditory nerve fibers. Present review article investigates the findings of previous research papers which have assessed speech and language outcome in children who underwent early cochlear implantation. Several databases, including PubMed, Google, Google Scholar, and Medline, were investigated for research papers on the speech and language outcomes of children who had early-life implants. According to previous research, early detection and intervention of hearing loss are critical for the growth of speech and language skills. The effect of early detection of hearing loss and early cochlear implantation on a child's overall speech-language and auditory growth is highlighted in this article.

The relationships between language, working memory and rapid naming in children with mild to moderate hearing loss

OBJECTIVE

Hearing loss is associated with reduced quality and quantity of auditory input, and difficulty in cognitive and language skills. This study aimed to investigate the relationship between language, working memory, and rapid naming skills in children with mild to moderate sensorineural hearing loss (MMHL).

METHODS

Twenty children with MMHL with the same auditory experience and demographical conditions using bilateral hearing aids were included. Verbal memory subscale of the Working Memory Scale (WMS), consisting of verbal short-term memory (V-STM) and verbal working memory (V-WM) subtests, was administered to all participants. They also completed rapid automatized naming tasks and standardized language measures.

RESULTS

The language score showed a moderate and significant correlation with verbal memory (VM) score (p = 0.03, r = 0.48) and a moderate and negative correlation with rapid automatized naming (RAN) duration (p = 0.06, r = -0.61). The VM score showed a moderate and significant negative correlation with RAN duration (p = 0.01, r = -0.67). The language level has a strong and significant positive correlation with V-STM (p = 0.007, r = 0.60), V-WM (p = 0.009, r = 0.58), and VM level (p = 0.003, r = 0.65). VM subtests levels have a strong and significant positive correlation with each other (p = 0.017, r = 0.53). RAN level has a strong and significant negative correlation with VM (p = 0.001, r = -0.70), V-WM (p = 0.001, r = -0.76), V-STM (p = 0.001, r = -0.69), and language level (p = 0.001, r = -0.77).

CONCLUSION

The results suggest that the language, verbal working memory, and rapid naming skills of children with MMHL are closely related. It is recommended that the relationship between verbal short-term memory, verbal working memory, rapid naming skills, and language skills should be considered in therapeutic and educational settings. To the best of our knowledge, this is the first study to examine the relationships between verbal-short-term -working memory, duration of rapid automatized naming, and language skills in children with MMHL.

Poor Performer: A Distinct Entity in Cochlear Implant Users?

INTRODUCTION

Several factors are known to influence speech perception in cochlear implant (CI) users. To date, the underlying mechanisms have not yet been fully clarified. Although many CI users achieve a high level of speech perception, a small percentage of patients does not or only slightly benefit from the CI (poor performer, PP). In a previous study, PP showed significantly poorer results on nonauditory-based cognitive and linguistic tests than CI users with a very high level of speech understanding (star performer, SP). We now investigate if PP also differs from the CI user with an average performance (average performer, AP) in cognitive and linguistic performance.

METHODS

Seventeen adult postlingually deafened CI users with speech perception scores in quiet of 55 (9.32) % (AP) on the German Freiburg monosyllabic speech test at 65 dB underwent neurocognitive (attention, working memory, short- and long-term memory, verbal fluency, inhibition) and linguistic testing (word retrieval, lexical decision, phonological input lexicon). The results were compared to the performance of 15 PP (speech perception score of 15 [11.80] %) and 19 SP (speech perception score of 80 [4.85] %). For statistical analysis, U-Test and discrimination analysis have been done.

RESULTS

Significant differences between PP and AP were observed on linguistic tests, in Rapid Automatized Naming (RAN: p = 0.0026), lexical decision (LexDec: p = 0.026), phonological input lexicon (LEMO: p = 0.0085), and understanding of incomplete words (TRT: p = 0.0024). AP also had significantly better neurocognitive results than PP in the domains of attention (M3: p = 0.009) and working memory (OSPAN: p = 0.041; RST: p = 0.015) but not in delayed recall (delayed recall: p = 0.22), verbal fluency (verbal fluency: p = 0.084), and inhibition (Flanker: p = 0.35). In contrast, no differences were found hereby between AP and SP. Based on the TRT and the RAN, AP and PP could be separated in 100%.

DISCUSSION

The results indicate that PP constitute a distinct entity of CI users that differs even in nonauditory abilities from CI users with an average speech perception, especially with regard to rapid word retrieval either due to reduced phonological abilities or limited storage. Further studies should investigate if improved word retrieval by increased phonological and semantic training results in better speech perception in these CI users.

Benefit of Bilateral Cochlear Implantation on Phonological Processing Skills in Deaf Children

HYPOTHESIS

Children with bilateral cochlear implants (CIs) would have better phonological processing skills than children with unilateral CIs because those with bilateral CIs have better speech perception abilities in noisy environments and higher levels of central auditory system development than those with unilateral CIs.

BACKGROUND

Previous studies have focused on the performance of children with bilateral CIs on standardized clinical assessments. However, these tests are not sufficiently sensitive to explain better speech and language outcomes in children with bilateral CIs than children with unilateral CIs. Thus, this study focused on phonological processing skills at more central levels of analysis that reflect the operation of cognitive processes.

METHOD

Twenty children with bilateral CIs and 20 children with unilateral CIs, aged 4 to 6 years, participated in this study. The children completed the experience-dependent tasks and phonological processing tasks. The experience-dependent tasks involved the monosyllabic word, articulation, and receptive vocabulary tests. The phonological processing tasks involved the phonological awareness, phonological memory, and rapid automatic naming tasks. Task performance was compared between the unilateral and bilateral CI groups.

RESULTS

Children with unilateral CIs performed similarly to children with bilateral CIs on all three experience-dependent tasks. However, children with bilateral CIs significantly outperformed children with unilateral CIs on all three phonological processing tasks. Among the phonological processing tasks, the rapid automatic naming task scores differentiated children with unilateral CIs from children with bilateral CIs.

CONCLUSIONS

Bilateral cochlear implantation may positively impact the phonological processing skills of deaf children.

Meta-Analytic Findings on Reading in Children With Cochlear Implants

This meta-analysis study aims to quantify the group differences in reading skills between children with cochlear implants and their hearing peers and between children with cochlear implants and children with hearing aids (aged between 3 and 18 years old). Of the 5,642 articles screened, 47 articles met predetermined inclusion criteria (published between 2002 and 2019). The robust variance estimation based meta-analysis models were used to synthesize all the effect sizes. Children with cochlear implants scored significantly lower than their hearing peers in phonological awareness (g = -1.62, p < 0.001), vocabulary (g = -1.50, p < 0.001), decoding (g = -1.24, p < 0.001), and reading comprehension (g = -1.39, p < 0.001), but not for fluency (g = -0.67, p = 0.054). Compared to children with hearing aids, children with cochlear implants scored significantly lower in phonological awareness (g = -0.30, p = 0.028). The percentage of unilateral cochlear implant negatively impacts the group difference between children with cochlear implants and their hearing peers. Findings from this study confirm a positive shift in reading outcomes for profoundly deaf children due to cochlear implantation. Some children with cochlear implants may need additional supports in educational settings.

Implicit learning of non-verbal regularities by deaf children with cochlear implants: An investigation with a dynamic temporal prediction task

Some deaf children continue to show difficulties in spoken language learning after cochlear implantation. Part of this variability has been attributed to poor implicit learning skills. However, the involvement of other processes (e.g. verbal rehearsal) has been underestimated in studies that show implicit learning deficits in the deaf population. In this study, we investigated the relationship between auditory deprivation and implicit learning of temporal regularities with a novel task specifically designed to limit the load on working memory, the amount of information processing, and the visual-motor integration skills required. Seventeen deaf children with cochlear implants and eighteen typically hearing children aged 5 to 11 years participated. Our results revealed comparable implicit learning skills between the two groups, suggesting that implicit learning might be resilient to a lack of early auditory stimulation. No significant correlation was found between implicit learning and language tasks. However, deaf children's performance suggests some weaknesses in inhibitory control.

Phonological Awareness Skills in Children With Early and Late Cochlear Implantation: Effects of Task and Phonological Unit

Purpose Phonological awareness (PA) skills are critical for spoken language acquisition and literacy. PA manifests in various skills that can be identified based on task performance and speech sound unit size. This study compared the PA skills of children with early cochlear implantation (E-CI), children with late cochlear implantation (L-CI), and children with typical hearing (TH) in relation to task and phonological unit. It also attempted to identify the significant predictors of PA skills in each CI and TH group. Method Twenty children with E-CI, 20 children with L-CI, and 20 children with TH participated in this study. PA skills were assessed using elision, blending, and segmenting tasks at both the syllabic and phonemic levels. Results The E-CI and L-CI groups performed significantly less well than the TH group on the elision and blending tasks at the syllabic level. However, the E-CI group performed at a similar level as the TH group in the segmenting tasks at both the syllabic and phonemic levels. The regression analysis identified age at implantation and receptive vocabulary scores as significant predictors of PA skills in children with CIs. Conclusions Although all the children with CIs had age-appropriate receptive vocabulary skills, the PA skills of both the E-CI and L-CI groups tended to lag behind those of the TH group in the elision and blending tasks at the syllabic level. Age at implantation and receptive vocabulary skills affected the development of PA skills in children with CIs.

The Relation Between Vocabulary Knowledge and Phonological Awareness in Children With Cochlear Implants

Purpose The purpose of this study was to evaluate the relation between lexical knowledge and phonological awareness performance of children with cochlear implants. Method Thirty children with cochlear implants (aged 5-7 years), 30 children with normal hearing matched for age, and 30 children with normal hearing matched for vocabulary size participated in the study. Children completed a vocabulary knowledge measure and three phonological awareness tasks with words that had high and low neighborhood density. Results Children with cochlear implants performed more poorly than their age-matched peers and similarly to their vocabulary-matched peers on phonological awareness tasks. When performance was analyzed according to the neighborhood density of the target word, children with cochlear implants and age-matched children performed better with high-density words. Across all groups, vocabulary size correlated significantly with phonological awareness performance. Conclusion Children with cochlear implants demonstrate delays in both vocabulary knowledge and phonological awareness performance, but children with cochlear implants appear to take advantage of lexical information similarly to their age-matched peers.

Spelling in Children With Cochlear Implants: Evidence of Underlying Processing Differences

This study compared the spelling skills and sub-skills of young children with cochlear implants (CIs) who use spoken language only (n = 14) with those of a same-aged typically hearing (TH) control group (n = 30). Spelling accuracy was assessed using irregular and nonsense word stimuli. Error and regression analyses were conducted to provide insight into the phonological and orthographic spelling strategies used by each group. Results indicated that children with CIs were as accurate as the TH group. However, misspellings made by the CI group were less phonologically plausible, and while nonword spelling accuracy was related to letter-sound knowledge for the TH group, the same relationship was non-significant for the CI group. Hence, despite demonstrating a similar degree of overall spelling success to TH children, children with CIs appeared to apply phonics skills less effectively.

Reading Development in Children With Cochlear Implants Who Communicate via Spoken Language: A Psycholinguistic Investigation

Purpose This study sought to comprehensively examine the reading skills and subskills of children with cochlear implants (CIs) and gain insight into the processes underlying their early reading development. Method Fourteen 6- to 9-year-old children with CIs were assessed on a range of reading and spoken language measures. Their performances were compared to a control group of 31 children with normal hearing (NH) of the same chronological and mental age. Group differences were examined using t tests and regression modeling. Results Children with CIs performed significantly worse than children with NH on reading accuracy, phonological processing, and spoken language tasks. The predominant predictor of reading comprehension was word reading accuracy for the CI group and listening comprehension for the NH group. Word reading profiles were similar across groups, with orthographic and phonological processing skills both contributing significant variance. Conclusions Children with CIs demonstrated more early reading difficulties than their peers with NH. As predicted by the Simple View of Reading model, successful reading comprehension for all children related to skills in listening comprehension and word recognition. The CI group's increased reliance on word reading accuracy when comprehending written text may stem from reduced word recognition automaticity. Despite showing reduced reading accuracy, children with CIs appeared to draw on orthographic and phonological skills to a similar degree as children with NH when reading words in isolation.

Early cochlear implantation: Verbal working memory, vocabulary, speech intelligibility and participant variables

OBJECTIVES

The purpose of this study was to compare performance in the areas of verbal working memory (VWM), vocabulary skills, and speech intelligibility between children with cochlear implants (CIs) and children with typical development (TD). The correlations between participant variables and the scores of children with CIs in VWM and the measures of language were examined. Also, it was important to identify which variables predict VWM in children with CIs.

METHODS

A total of 59 children participated in this study with the study group being comprised of 31 children who had received a CI and the control group being comprised of 28 children with TD. The assessment techniques utilized in this study were the backward digit span (BDS), non-word repetition, speech intelligibility, and vocabulary skills.

RESULTS

The study results revealed significant differences in the non-word repetition, speech intelligibility, and vocabulary tasks. The results all favored the typically developing children while the findings for the BDS were equal for both groups.

DISCUSSION

In children with CIs the results for VWM observed in this study are believed to be related to the modality of assessment presentation, prior vocabulary knowledge, and familiarity with the presented material. The results from this study also revealed that the variables which predicted VWM in children with CIs were speech perception, duration of CI use, and vocabulary knowledge.

Passive sentence comprehension difficulties and its related factors in children with cochlear implants

OBJECTIVES

The purposes of this study were to investigate which syntactic structures, from active and passive sentences, sensitively differentiate children with cochlear implants (CIs) from children with normal hearing (NH), to explore the correlations among working memory (WM) and other factors for each group, and to examine predictors of the active and passive sentence scores for both groups.

METHODS

Twenty deaf children with CIs and 20 children with NH, aged 8-14 years, were included in this study. Sentence comprehension skills were measured using the picture-pointing comprehension task, which consisted of active and passive sentences. The WM capacity was tested by the digit forward, digit backward, word forward, and word backward span tasks.

RESULTS

Passive sentence type was a significant predictor to differentiate between the two groups (p < .05). In the CI group, passive sentence scores were significantly correlated with age, duration of an implant use, receptive vocabulary scores, and WM scores (all p values < .05). In the stepwise regression analysis, WM capacity was a significant factor in predicting the passive sentence scores of children with CIs (p < .05).

CONCLUSION

Passive sentence type was a significant factor in distinguishing the CI group from the NH group. The WM capacity was an important predictor accounting for individual differences in processing complex sentence types for children with CIs. The results indicate that a complex syntactic form may serve as a clinically critical index in detecting higher-level cognitive and linguistic processing difficulties in good performers after implantation.

Profiling morpho-syntactical development of cochlear implanted children with TR-LARSP

This research aims to describe the grammatical development of Turkish-speaking children with cochlear implants (CI) using the Turkish adaptation of the Language Assessment and Remediation Profile (LARSP). The study was conducted on a total of 15 children with CIs aged 43-87 months with 22-45 months of hearing age. A total of 750 utterances were elicited from the CI group's recorded speech samples and analysed using the methodology of Turkish-Language Assessment and Remediation Profile (TR-LARSP). A cross-sectional descriptive model is used in the study. The results show that there is a significant difference in the acquisition of grammatical structures in children with CIs as compared to typically developing (TD) age-matched children in Turkish. In conclusion, this study suggests that after the implantation of these children, the speech therapist should consider the acquisition time of morpho-syntactical structures before making a language-based therapy plan.

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 lexical development of children with hearing impairment and associated factors

PURPOSE

This study aimed at analyzing the association between the lexical development of children with hearing impairment and their psychosocial and socioeconomic characteristics and medical history.

METHODS

An analytic transversal study was conducted in an Auditive Health Attention Service. One hundred and ten children from 6 to 10 years old using hearing aids and presenting hearing loss that ranged from light to deep levels were evaluated. All children were subjected to oral, written language and auditory perception tests. Parents answered a structured questionnaire to collect data from their medical history and socioeconomic status, and questionnaires about the features of the family environment and psychosocial characteristics. Multivariate analysis was performed by logistic regression, being the initial model composed by variables with p<0,20 in the univariate analysis. In the final model, we adopted a significance level of 5%.

RESULTS

The final model of the multivariate analysis showed an association between the performance on the vocabulary test and the results of phonemic discrimination test (OR=0.81; 95%CI 0.73-0.89).

CONCLUSION

The results show the importance of stimulating the auditory processing, particularly the phonemic discrimination skill, throughout the rehabilitation process of children with hearing impairment. This stimulation can enhance lexical development and minimize the metalanguage and learning difficulties often observed in these children.