Cognitive factors and cochlear implants: some thoughts on perception, learning, and memory in speech perception

Task-Specific Rapid Auditory Perceptual Learning in Adult Cochlear Implant Recipients: What Could It Mean for Speech Recognition

OBJECTIVES

Speech recognition in cochlear implant (CI) recipients is quite variable, particularly in challenging listening conditions. Demographic, audiological, and cognitive factors explain some, but not all, of this variance. The literature suggests that rapid auditory perceptual learning explains unique variance in speech recognition in listeners with normal hearing and those with hearing loss. The present study focuses on the early adaptation phase of task-specific rapid auditory perceptual learning. It investigates whether adult CI recipients exhibit this learning and, if so, whether it accounts for portions of the variance in their recognition of fast speech and speech in noise.

DESIGN

Thirty-six adult CI recipients (ages = 35 to 77, M = 55) completed a battery of general speech recognition tests (sentences in speech-shaped noise, four-talker babble noise, and natural-fast speech), cognitive measures (vocabulary, working memory, attention, and verbal processing speed), and a rapid auditory perceptual learning task with time-compressed speech. Accuracy in the general speech recognition tasks was modeled with a series of generalized mixed models that accounted for demographic, audiological, and cognitive factors before accounting for the contribution of task-specific rapid auditory perceptual learning of time-compressed speech.

RESULTS

Most CI recipients exhibited early task-specific rapid auditory perceptual learning of time-compressed speech within the course of the first 20 sentences. This early task-specific rapid auditory perceptual learning had unique contribution to the recognition of natural-fast speech in quiet and speech in noise, although the contribution to natural-fast speech may reflect the rapid learning that occurred in this task. When accounting for demographic and cognitive characteristics, an increase of 1 SD in the early task-specific rapid auditory perceptual learning rate was associated with ~52% increase in the odds of correctly recognizing natural-fast speech in quiet, and ~19% to 28% in the odds of correctly recognizing the different types of speech in noise. Age, vocabulary, attention, and verbal processing speed also had unique contributions to general speech recognition. However, their contribution varied between the different general speech recognition tests.

CONCLUSIONS

Consistent with previous findings in other populations, in CI recipients, early task-specific rapid auditory perceptual, learning also accounts for some of the individual differences in the recognition of speech in noise and natural-fast speech in quiet. Thus, across populations, the early rapid adaptation phase of task-specific rapid auditory perceptual learning might serve as a skill that supports speech recognition in various adverse conditions. In CI users, the ability to rapidly adapt to ongoing acoustical challenges may be one of the factors associated with good CI outcomes. Overall, CI recipients with higher cognitive resources and faster rapid learning rates had better speech recognition.

Parent-child sensorimotor coordination in toddlers with and without hearing loss

Infants experience the world through their actions with objects and their interactions with other people, especially their parents. Prior research has shown that school-age children with hearing loss experience poorer quality interactions with typically hearing parents, yet little is known about parent-child interactions between toddlers with hearing loss and their parents early in life. In the current study, we used mobile eye-tracking to investigate parent-child interactions in toddlers with and without hearing loss (mean ages: 19.42 months, SD = 3.41 months). Parents and toddlers engaged in a goal-directed, interactive task that involved inserting coins into a slot and required joint coordination between the parent and the child. Overall, findings revealed that deaf toddlers demonstrate typical action skills in line with their hearing peers and engage in similar interactions with their parents during social interactions. Findings also revealed that deaf toddlers explored objects more and showed more temporal stability in their motor movements (i.e. less variation in their timing across trials) than hearing peers, suggesting further adaptability of the deaf group to their atypical sensory environment rather than poorer coordination. In contrast to previous research, findings suggest an intact ability of deaf toddlers to coordinate their actions with their parents and highlight the adaptability within dyads who have atypical sensory experiences.

Neurocognitive function in children with cochlear implants and hearing aids: a systematic review

Purpose

To systematically review the existing literature that examines the relationship between cognition, hearing, and language in children using cochlear implants and hearing aids.

Method

The review has been registered in Prospero (Registration: CRD 42020203974). The review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis and examined the scientific literature in VHL, MEDLINE, CINAHL, Scopus, WOS, and Embase. It included original observational studies in children using hearing aids and/or cochlear implants who underwent cognitive and auditory and/or language tests. Data were extracted from the studies and their level of evidence was graded with the Oxford Center for Evidence-Based Medicine: Levels of Evidence. Meta-analysis could not be performed due to data heterogeneity. Outcomes are described in narrative and tables synthesis.

Results

The systematic search and subsequent full-text evaluation identified 21 studies, conducted in 10 different countries. Altogether, their samples comprised 1,098 individuals, aged 0.16-12.6 years. The studies assessed the following cognitive domains: memory, nonverbal cognition, reasoning, attention, executive functions, language, perceptual-motor function, visuoconstructive ability, processing speed, and phonological processing/phonological memory. Children with hearing loss using cochlear implants and hearing aids scored significantly lower in many cognitive functions than normal hearing (NH) children. Neurocognitive functions were correlated with hearing and language outcomes.

Conclusion

Many cognitive tools were used to assess cognitive function in children with hearing devices. Results suggest that children with cochlear implants and hearing aids have cognitive deficits; these outcomes are mainly correlated with vocabulary. This study highlights the need to understand children's cognitive function and increase the knowledge of the relationship between cognition, language, and hearing in children using cochlear implants and hearing aids.

Unimodal versus bimodal auditory stimulation in inner ear malformations: Cognitive, language, and motor performance

Purpose

New perspectives on rehabilitation options for inner ear malformations have still been studied in the literature. This study investigated the cognitive, language, and motor skills of auditory brainstem implant (ABI) users in unimodal and bimodal groups.

Methods

The motor competency of the participants was assessed with Bruininks-Oseretsky Motor Proficiency Test-2 Short Form (BOT2 SF). Language performance was evaluated by the test of Early Language Development-3 and Speech Intelligibility Rating. Word identification, sentence recognition tests, and Categories of Auditory Performance were used to assess auditory perception skills. To examine the cognitive performance, Cancellation Test and Gesell Copy Form were administered. All the tests were conducted in a quiet environment without any distractions.

Results

The participants were divided into two groups: (1) 17 children in the unimodal group and (2) 11 children in the bimodal (who used a cochlear implant on one side and ABI on the other side) group. There were significant correlations between the chronological age of participants and BOT2 SF total score, cancellation tests, auditory perception tests, and language performance. Similarly, there were significant correlations between the duration of ABI use and auditory perception tests, language performance, cancellation test, and some BOT2 SF subtests (r = -0.47 to -0.60, p < .001). There was no significant difference between the unimodal and bimodal groups in any task (p > .05). However, there were moderate-to-strong correlations among the auditory perception tests, cancellation test, language test, and BOT2 SF total score and subtests (r = 0.40 to 0.55, p < .05).

Conclusion

Although there were no significant differences between bimodal and unimodal groups, a holistic approach, which indicates that hearing and balance issues can have broader impacts on a person's physical, emotional, social, and psychological aspects, should be used in the assessment process.

Level of Evidence

Level 4.

Gahvora cradling in Tajikistan: Cultural practices and associations with motor development

In Tajikistan, infants are bound supine in a "gahvora" cradle that severely restricts movement. Does cradling affect motor development and body growth? In three studies (2013-2018), we investigated associations between time in the gahvora (within days and across age) and motor skills and flattened head dimensions in 8-24-month-old Tajik infants (N = 269, 133 girls, 136 boys)) and 4.3-5.1-year-old children (N = 91, 53 girls, 38 boys). Infants had later motor onset ages relative to World Health Organization standards and pronounced brachycephaly; cradling predicted walk onset age and the proficiency of sitting, crawling, and walking. By 4-5 years, children's motor skills were comparable with US norms. Cultural differences in early experiences offer a unique lens onto developmental processes and equifinality in development.

Streamlining experiment design in cognitive hearing science using OpenSesame

Auditory science increasingly builds on concepts and testing paradigms originated in behavioral psychology and cognitive neuroscience - an evolution of which the resulting discipline is now known as cognitive hearing science. Experimental cognitive hearing science paradigms call for hybrid cognitive and psychobehavioral tests such as those relating the attentional system, working memory, and executive functioning to low-level auditory acuity or speech intelligibility. Building complex multi-stimuli experiments can rapidly become time-consuming and error-prone. Platform-based experiment design can help streamline the implementation of cognitive hearing science experimental paradigms, promote the standardization of experiment design practices, and ensure reliability and control. Here, we introduce a set of features for the open-source python-based OpenSesame platform that allows the rapid implementation of custom behavioral and cognitive hearing science tests, including complex multichannel audio stimuli while interfacing with various synchronous inputs/outputs. Our integration includes advanced audio playback capabilities with multiple loudspeakers, an adaptive procedure, compatibility with standard I/Os and their synchronization through implementation of the Lab Streaming Layer protocol. We exemplify the capabilities of this extended OpenSesame platform with an implementation of the three-alternative forced choice amplitude modulation detection test and discuss reliability and performance. The new features are available free of charge from GitHub: https://github.com/elus-om/BRM_OMEXP .

Contribution of Verbal Learning & Memory and Spectro-Temporal Discrimination to Speech Recognition in Cochlear Implant Users

OBJECTIVES

Existing cochlear implant (CI) outcomes research demonstrates a high degree of variability in device effectiveness among experienced CI users. Increasing evidence suggests that verbal learning and memory (VL&M) may have an influence on speech recognition with CIs. This study examined the relations in CI users between visual measures of VL&M and speech recognition in a series of models that also incorporated spectro-temporal discrimination. Predictions were that (1) speech recognition would be associated with VL&M abilities and (2) VL&M would contribute to speech recognition outcomes above and beyond spectro-temporal discrimination in multivariable models of speech recognition.

METHODS

This cross-sectional study included 30 adult postlingually deaf experienced CI users who completed a nonauditory visual version of the California Verbal Learning Test-Second Edition (v-CVLT-II) to assess VL&M, and the Spectral-Temporally Modulated Ripple Test (SMRT), an auditory measure of spectro-temporal processing. Participants also completed a battery of word and sentence recognition tasks.

RESULTS

CI users showed significant correlations between some v-CVLT-II measures (short-delay free- and cued-recall, retroactive interference, and "subjective" organizational recall strategies) and speech recognition measures. Performance on the SMRT was correlated with all speech recognition measures. Hierarchical multivariable linear regression analyses showed that SMRT performance accounted for a significant degree of speech recognition outcome variance. Moreover, for all speech recognition measures, VL&M scores contributed independently in addition to SMRT.

CONCLUSION

Measures of spectro-temporal discrimination and VL&M were associated with speech recognition in CI users. After accounting for spectro-temporal discrimination, VL&M contributed independently to performance on measures of speech recognition for words and sentences produced by single and multiple talkers.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:661-669, 2023.

Strategic Pauses Relieve Listeners from the Effort of Listening to Fast Speech: Data Limited and Resource Limited Processes in Narrative Recall by Adult Users of Cochlear Implants

Speech that has been artificially accelerated through time compression produces a notable deficit in recall of the speech content. This is especially so for adults with cochlear implants (CI). At the perceptual level, this deficit may be due to the sharply degraded CI signal, combined with the reduced richness of compressed speech. At the cognitive level, the rapidity of time-compressed speech can deprive the listener of the ordinarily available processing time present when speech is delivered at a normal speech rate. Two experiments are reported. Experiment 1 was conducted with 27 normal-hearing young adults as a proof-of-concept demonstration that restoring lost processing time by inserting silent pauses at linguistically salient points within a time-compressed narrative ("time-restoration") returns recall accuracy to a level approximating that for a normal speech rate. Noise vocoder conditions with 10 and 6 channels reduced the effectiveness of time-restoration. Pupil dilation indicated that additional effort was expended by participants while attempting to process the time-compressed narratives, with the effortful demand on resources reduced with time restoration. In Experiment 2, 15 adult CI users tested with the same (unvocoded) materials showed a similar pattern of behavioral and pupillary responses, but with the notable exception that meaningful recovery of recall accuracy with time-restoration was limited to a subgroup of CI users identified by better working memory spans, and better word and sentence recognition scores. Results are discussed in terms of sensory-cognitive interactions in data-limited and resource-limited processes among adult users of cochlear implants.

Exceptional Speech Recognition Outcomes After Cochlear Implantation: Lessons From Two Case Studies

PURPOSE

Individual differences and variability in outcomes following cochlear implantation (CI) in patients with hearing loss remain significant unresolved clinical problems. Case reports of specific individuals allow for detailed examination of the information processing mechanisms underlying variability in outcomes. Two adults who displayed exceptionally good postoperative CI outcomes shortly after activation were administered a novel battery of auditory, speech recognition, and neurocognitive processing tests.

METHOD

A case study of two adult CI recipients with postlingually acquired hearing loss who displayed excellent postoperative speech recognition scores within 3 months of initial activation. Preoperative City University of New York sentence testing and a postoperative battery of sensitive speech recognition tests were combined with auditory and visual neurocognitive information processing tests to uncover their strengths, weaknesses, and milestones.

RESULTS

Preactivation CUNY auditory-only (A) scores were < 5% correct while the auditory + visual (A + V) scores were > 74%. Acoustically with their CIs, both participants' scores on speech recognition, environmental sound identification and speech in noise tests exceeded average CI users scores by 1-2 standard deviations. On nonacoustic visual measures of language and neurocognitive functioning, both participants achieved above average scores compared with normal hearing adults in vocabulary knowledge, rapid phonological coding of visually presented words and nonwords, verbal working memory, and executive functioning.

CONCLUSIONS

Measures of multisensory (A + V) speech recognition and visual neurocognitive functioning were associated with excellent speech recognition outcomes in two postlingual adult CI recipients. These neurocognitive information processing domains may underlie the exceptional speech recognition performance of these two patients and offer new directions for research explaining variability in postimplant outcomes. Results further suggest that current clinical outcome measures should be expanded beyond the conventional speech recognition measures to include more sensitive robust tests of speech recognition as well as neurocognitive measures of working memory, vocabulary, lexical access, and executive functioning.

A Modified Pediatric Ranked Order Speech Perception Score to Assess Speech Recognition Development in Children With Cochlear Implants

PURPOSE

Characterizing and comparing speech recognition development in children with cochlear implants (CIs) is challenging because of variations in test type. This retrospective cohort study modified the Pediatric Ranked Order Speech Perception (PROSPER) scoring system to (a) longitudinally analyze the speech perception of children with CIs and (b) examine the role of age at CI activation, listening mode (i.e., unilateral or bilateral implantation), and interimplant interval.

METHOD

Postimplantation speech recognition scores from 31 children with prelingual, severe-to-profound hearing loss who received CIs were analyzed (12 with unilateral CI [UniCI], 13 with sequential bilateral CIs [SEQ BiCIs], and six with simultaneous BiCIs). Data were extracted from the Massachusetts Eye and Ear Audiology database. A version of the PROSPER score was modified to integrate the varying test types by mapping raw scores from different tests into a single score. The PROSPER scores were used to construct speech recognition growth curves of the implanted ears, which were characterized by the slope of the growth phase, the time from activation to the plateau onset, and the score at the plateau.

RESULTS

While speech recognition improved considerably for children following implantation, the growth rates and scores at the plateau were highly variable. In first implanted ears, later implantation was associated with poorer scores at the plateau (β = -0.15, p = .01), but not growth rate. The first implanted ears of children with BiCIs had better scores at the plateau than those with UniCI (β = 0.59, p = .02). Shorter interimplant intervals in children with SEQ BiCIs promoted faster speech recognition growth of the first implanted ears.

CONCLUSION

The modified PROSPER score could be used clinically to track speech recognition development in children with CIs, to assess influencing factors, and to assist in developing and evaluating patient-specific intervention strategies.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20113538.

Identification and Comprehension of Narrow Focus by Arabic-Speaking Adolescents With Moderate-to-Profound Hearing Loss

PURPOSE

Processing narrow focus (NF), the stressed word in the sentence, includes both the perceptual ability to identify the stressed word in the sentence and the pragmatic-semantic ability to comprehend the nonexplicit linguistic message. NF and its underlying meaning can be conveyed only via the auditory modality. Therefore, NF can be considered as a measure for assessing the efficacy of the hearing aid (HA) and cochlear implants (CIs) for acquiring nonexplicit language skills. The purpose of this study was to assess identification and comprehension of NF by HA and CI users who are native speakers of Arabic and to associate NF outcomes with speech perception and cognitive and linguistic abilities.

METHOD

A total of 46 adolescents (age range: 11;2-18;8) participated: 18 with moderate-to-severe hearing loss who used HAs, 10 with severe-to-profound hearing loss who used CIs, and 18 with typical hearing (TH). Test materials included the Arabic Narrow Focus Test (ANFT), which includes three subtests assessing identification (ANFT1), comprehension of NF in simple four-word sentences (ANFT2), and longer sentences with a construction list at the clause or noun phrase level (ANFT3). In addition, speech perception, vocabulary, and working memory were assessed.

RESULTS

All the participants successfully identified the word carrying NF, with no significant difference between the groups. Comprehension of NF in ANFT2 and ANFT3 was reduced for HA and CI users compared with TH peers, and speech perception, hearing status, and memory for digits predicted the variability in the overall results of ANFT1, ANFT2, and ANFT3, respectively.

CONCLUSIONS

Arabic speakers who used HAs or CIs were able to identify NF successfully, suggesting that the acoustic cues were perceptually available to them. However, HA and CI users had considerable difficulty in understanding NF. Different factors may contribute to this difficulty, including the memory load during the task as well as pragmatic-linguistic knowledge on the possible meanings of NF.

Preoperative Visual Measures of Verbal Learning and Memory and their Relations to Speech Recognition After Cochlear Implantation

OBJECTIVES

This study examined the performance of a group of adult cochlear implant (CI) candidates (CIC) on visual tasks of verbal learning and memory. Preoperative verbal learning and memory abilities of the CIC group were compared with a group of older normal-hearing (ONH) control participants. Relations between preoperative verbal learning and memory measures and speech recognition outcomes after 6 mo of CI use were also investigated for a subgroup of the CICs.

DESIGN

A group of 80 older adult participants completed a visually presented multitrial free recall task. Measures of word recall, repetition learning, and the use of self-generated organizational strategies were collected from a group of 49 CICs, before cochlear implantation, and a group of 31 ONH controls. Speech recognition outcomes were also collected from a subgroup of 32 of the CIC participants who returned for testing 6 mo after CI activation.

RESULTS

CICs demonstrated poorer verbal learning performance compared with the group of ONH control participants. Among the preoperative verbal learning and memory measures, repetition learning slope and measures of self-generated organizational clustering strategies were the strongest predictors of post-CI speech recognition outcomes.

CONCLUSIONS

Older adult CI candidates present with verbal learning and memory deficits compared with older adults without hearing loss, even on visual tasks that are independent from the direct effects of audibility. Preoperative verbal learning and memory processes reflecting repetition learning and self-generated organizational strategies in free recall were associated with speech recognition outcomes 6 months after implantation. The pattern of results suggests that visual measures of verbal learning may be a useful predictor of outcomes in postlingual adult CICs.

Vestibular Evaluation and Management of Children with Sensorineural Hearing Loss

Vestibular dysfunction is the most common comorbidity associated with childhood sensorineural hearing loss. Early identification of vestibular dysfunction enables early intervention to mitigate its impact of motor, behavioral, and neurocognitive deficits of developing children. Screening for vestibular impairment can be achieved in the busy clinical setting.

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.

Spectral resolution and speech perception after cochlear implantation using the round window versus cochleostomy technique

OBJECTIVE

To evaluate the spectral resolution achieved with a cochlear implant in users who were implanted using round window route electrode insertion versus a traditional cochleostomy technique.

METHODS

Twenty-six patients were classified into two groups according to the surgical approach: one group (n = 13) underwent cochlear implantation via the round window technique and the other group (n = 13) underwent surgery via cochleostomy.

RESULTS

A statistically significant difference was found in spectral ripple discrimination scores between the round window and cochleostomy groups. The round window group performed almost two times better than the cochleostomy group. Differences between Turkish matrix sentence test scores were not statistically significant.

CONCLUSION

The spectral ripple discrimination scores of patients who had undergone round window cochlear implant electrode insertion were superior to those of patients whose cochlear implants were inserted using a classical cochleostomy technique.

The impact of mild-to-severe hearing loss on the neural dynamics serving verbal working memory processing in children

Children with hearing loss (CHL) exhibit delays in language function relative to children with normal hearing (CNH). However, evidence on whether these delays extend into other cognitive domains such as working memory is mixed, with some studies showing decrements in CHL and others showing CHL performing at the level of CNH. Despite the growing literature investigating the impact of hearing loss on cognitive and language development, studies of the neural dynamics that underlie these cognitive processes are notably absent. This study sought to identify the oscillatory neural responses serving verbal working memory processing in CHL compared to CNH. To this end, participants with and without hearing loss performed a verbal working memory task during magnetoencephalography. Neural oscillatory responses associated with working memory encoding and maintenance were imaged separately, and these responses were statistically evaluated between CHL and CNH. While CHL performed as well on the task as CNH, CHL exhibited significantly elevated alpha-beta activity in the right frontal and precentral cortices during encoding relative to CNH. In contrast, CHL showed elevated alpha maintenance-related activity in the right precentral and parieto-occipital cortices. Crucially, right superior frontal encoding activity and right parieto-occipital maintenance activity correlated with language ability across groups. These data suggest that CHL may utilize compensatory right-hemispheric activity to achieve verbal working memory function at the level of CNH. Neural behavior in these regions may impact language function during crucial developmental ages.

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.

Individual Differences in Lexical Access Among Cochlear Implant Users

Purpose The current study investigates how individual differences in cochlear implant (CI) users' sensitivity to word-nonword differences, reflecting lexical uncertainty, relate to their reliance on sentential context for lexical access in processing continuous speech. Method Fifteen CI users and 14 normal-hearing (NH) controls participated in an auditory lexical decision task (Experiment 1) and a visual-world paradigm task (Experiment 2). Experiment 1 tested participants' reliance on lexical statistics, and Experiment 2 studied how sentential context affects the time course and patterns of lexical competition leading to lexical access. Results In Experiment 1, CI users had lower accuracy scores and longer reaction times than NH listeners, particularly for nonwords. In Experiment 2, CI users' lexical competition patterns were, on average, similar to those of NH listeners, but the patterns of individual CI users varied greatly. Individual CI users' word-nonword sensitivity (Experiment 1) explained differences in the reliance on sentential context to resolve lexical competition, whereas clinical speech perception scores explained competition with phonologically related words. Conclusions The general analysis of CI users' lexical competition patterns showed merely quantitative differences with NH listeners in the time course of lexical competition, but our additional analysis revealed more qualitative differences in CI users' strategies to process speech. Individuals' word-nonword sensitivity explained different parts of individual variability than clinical speech perception scores. These results stress, particularly for heterogeneous clinical populations such as CI users, the importance of investigating individual differences in addition to group averages, as they can be informative for clinical rehabilitation. Supplemental Material https://doi.org/10.23641/asha.11368106.

Nonverbal Reasoning as a Contributor to Sentence Recognition Outcomes in Adults With Cochlear Implants

HYPOTHESIS

Significant variability in speech recognition persists among postlingually deafened adults with cochlear implants (CIs). We hypothesize that scores of nonverbal reasoning predict sentence recognition in adult CI users.

BACKGROUND

Cognitive functions contribute to speech recognition outcomes in adults with hearing loss. These functions may be particularly important for CI users who must interpret highly degraded speech signals through their devices. This study used a visual measure of reasoning (the ability to solve novel problems), the Raven's Progressive Matrices (RPM), to predict sentence recognition in CI users.

METHODS

Participants were 39 postlingually deafened adults with CIs and 43 age-matched normal-hearing (NH) controls. CI users were assessed for recognition of words in sentences in quiet, and NH controls listened to eight-channel vocoded versions to simulate the degraded signal delivered by a CI. A computerized visual task of the RPM, requiring participants to identify the correct missing piece in a 3×3 matrix of geometric designs, was also performed. Particular items from the RPM were examined for their associations with sentence recognition abilities, and a subset of items on the RPM was tested for the ability to predict degraded sentence recognition in the NH controls.

RESULTS

The overall number of items answered correctly on the 48-item RPM significantly correlated with sentence recognition in CI users (r = 0.35-0.47) and NH controls (r = 0.36-0.57). An abbreviated 12-item version of the RPM was created and performance also correlated with sentence recognition in CI users (r = 0.40-0.48) and NH controls (r = 0.49-0.56).

CONCLUSIONS

Nonverbal reasoning skills correlated with sentence recognition in both CI and NH subjects. Our findings provide further converging evidence that cognitive factors contribute to speech processing by adult CI users and can help explain variability in outcomes. Our abbreviated version of the RPM may serve as a clinically meaningful assessment for predicting sentence recognition outcomes in CI users.

The effectiveness of a specifically-designed language intervention protocol on the cochlear implanted children's communication development

OBJECTIVE

Although various studies have depicted the importance of language intervention programs in facilitating language acquisition in cochlear implanted children, to this date rarely has a specific language intervention approach been recommended as better than the other and no best practice has been introduced in terms of language acquisition outcomes. Thus, the therapists remain uncertain as to which approach to follow and how to apply evidence to practice. Hence, the main goal of this study was to take a step in this regard by comparing the communication development of pediatric cochlear implant users who enrolled in two different language intervention approaches: the routine auditory-verbal approach, and the routine auditory-verbal approach plus a new intervention protocol specifically designed to enhance receptive vocabulary development in cochlear implanted children.

METHOD AND MATERIALS

This prospective experimental study compared the receptive and expressive communication developmental scores of 26 cochlear implanted 20-24 months old children who received both a routine auditory-verbal intervention and a new cognitive based intervention protocol specifically designed to enhance receptive vocabulary development, with that of a group of 25 participants whose intervention program was only auditory-verbal. The children were recruited from Fars cochlear implant center situated in the city of Shiraz in Iran, and were assigned randomly to the two groups. The communication development of both groups was evaluated by the Bayley scales of Infant and Toddler Development- Third Edition, and statistical analysis was performed using the Statistical Package for Social Sciences-version 21(SPSS-21).

RESULTS

The two groups were not significantly different in terms of age, sex and parents' educational level. Both the receptive and expressive communication outcomes of the children who received auditory-verbal as well as the new specifically-designed cognitive-based intervention protocol focusing on receptive vocabulary enhancement, were significantly higher than the control group (p < 0.001).

CONCLUSION

The new specifically-designed cognitive-based language intervention protocol focusing on receptive vocabulary enhancement was significantly more effective in promoting and enhancing the communication development of cochlear implanted children than the routine auditory-verbal intervention.

How Does Nonverbal Reasoning Affect Sentence Recognition in Adults with Cochlear Implants and Normal-Hearing Peers?

BACKGROUND

Previous research has demonstrated an association of scores on a visual test of nonverbal reasoning, Raven's Progressive Matrices (RPM), with scores on open-set sentence recognition in quiet for adult cochlear implant (CI) users as well as for adults with normal hearing (NH) listening to noise-vocoded sentence materials. Moreover, in that study, CI users demonstrated poorer nonverbal reasoning when compared with NH peers. However, it remains unclear what underlying neurocognitive processes contributed to the association of nonverbal reasoning scores with sentence recognition, and to the poorer scores demonstrated by CI users.

OBJECTIVES

Three hypotheses were tested: (1) nonverbal reasoning abilities of adult CI users and normal-hearing (NH) age-matched peers would be predicted by performance on more basic neurocognitive measures of working memory capacity, information-processing speed, inhibitory control, and concentration; (2) nonverbal reasoning would mediate the effects of more basic neurocognitive functions on sentence recognition in both groups; and (3) group differences in more basic neurocognitive functions would explain the group differences previously demonstrated in nonverbal reasoning.

METHOD

Eighty-three participants (40 CI and 43 NH) underwent testing of sentence recognition using two sets of sentence materials: sentences produced by a single male talker (Harvard sentences) and high-variability sentences produced by multiple talkers (Perceptually Robust English Sentence Test Open-set, PRESTO). Participants also completed testing of nonverbal reasoning using a visual computerized RPM test, and additional neurocognitive assessments were collected using a visual Digit Span test and a Stroop Color-Word task. Multivariate regression analyses were performed to test our hypotheses while treating age as a covariate.

RESULTS

In the CI group, information processing speed on the Stroop task predicted RPM performance, and RPM scores mediated the effects of information processing speed on sentence recognition abilities for both Harvard and PRESTO sentences. In contrast, for the NH group, Stroop inhibitory control predicted RPM performance, and a trend was seen towards RPM scores mediating the effects of inhibitory control on sentence recognition, but only for PRESTO sentences. Poorer RPM performance in CI users than NH controls could be partially attributed to slower information processing speed.

CONCLUSIONS

Neurocognitive functions contributed differentially to nonverbal reasoning performance in CI users as compared with NH peers, and nonverbal reasoning appeared to partially mediate the effects of these different neurocognitive functions on sentence recognition in both groups, at least for PRESTO sentences. Slower information processing speed accounted for poorer nonverbal reasoning scores in CI users. Thus, it may be that prolonged auditory deprivation contributes to cognitive decline through slower information processing.

Word Learning in Children With Cochlear Implants: Examining Performance Relative to Hearing Peers and Relations With Age at Implantation

OBJECTIVES

This study had two key objectives. First, to examine whether children who receive cochlear implants (CIs) before the age of 3 years and who are experienced implant users (mean length of CI use = 6 years; range = 4 to 9 years) show deficits on a word learning task relative to their hearing peers. Second, to examine whether variation in age at implantation within the first 3 years of life relates to later word learning abilities.

DESIGN

Twenty-one 6- to 10-year-old children with CIs, 21 chronological age-matched (AM) hearing children, and 21 vocabulary-matched hearing children completed an auditory word learning task in which they were required to learn the names of eight rare animals. Comprehension and production probes tested their learning of these unfamiliar words.

RESULTS

The children with CIs performed similarly to AM peers on the comprehension phase of the word learning task. Their production performance was significantly poorer than the AM group but was in line with that of their younger vocabulary-matched hearing peers. Differences between the CI and AM groups were accounted for by differences between the groups in terms of their existing vocabulary knowledge. Within the CI group, there was no evidence of an association between age at implantation and performance on the word learning task, but existing vocabulary size showed strong positive correlations with word learning performance, after adjustment for chronological age.

CONCLUSIONS

When implanted by the age of 3 years, and with over 4 years CI experience, 6- to 10-year-old children are able to perform similarly to their AM hearing peers in terms of their comprehension of newly learned words. Producing accurate phonological forms of newly learned words may be a more challenging task for children with CIs, but their production performance is consistent with their vocabulary size. This cross-sectional study provides support for a relationship between existing vocabulary size and novel word learning skills in children with CIs; future longitudinal studies should test the hypothesis that this relationship is developmentally reciprocal.

Verbal Learning and Memory After Cochlear Implantation in Postlingually Deaf Adults: Some New Findings with the CVLT-II

OBJECTIVES

Despite the importance of verbal learning and memory in speech and language processing, this domain of cognitive functioning has been virtually ignored in clinical studies of hearing loss and cochlear implants in both adults and children. In this article, we report the results of two studies that used a newly developed visually based version of the California Verbal Learning Test-Second Edition (CVLT-II), a well-known normed neuropsychological measure of verbal learning and memory.

DESIGN

The first study established the validity and feasibility of a computer-controlled visual version of the CVLT-II, which eliminates the effects of audibility of spoken stimuli, in groups of young normal-hearing and older normal-hearing (ONH) adults. A second study was then carried out using the visual CVLT-II format with a group of older postlingually deaf experienced cochlear implant (ECI) users (N = 25) and a group of ONH controls (N = 25) who were matched to ECI users for age, socioeconomic status, and nonverbal IQ. In addition to the visual CVLT-II, subjects provided data on demographics, hearing history, nonverbal IQ, reading fluency, vocabulary, and short-term memory span for visually presented digits. ECI participants were also tested for speech recognition in quiet.

RESULTS

The ECI and ONH groups did not differ on most measures of verbal learning and memory obtained with the visual CVLT-II, but deficits were identified in ECI participants that were related to recency recall, the buildup of proactive interference, and retrieval-induced forgetting. Within the ECI group, nonverbal fluid IQ, reading fluency, and resistance to the buildup of proactive interference from the CVLT-II consistently predicted better speech recognition outcomes.

CONCLUSIONS

Results from this study suggest that several underlying foundational neurocognitive abilities are related to core speech perception outcomes after implantation in older adults. Implications of these findings for explaining individual differences and variability and predicting speech recognition outcomes after implantation are discussed.

Brain Plasticity Can Predict the Cochlear Implant Outcome in Adult-Onset Deafness

Sensory plasticity, which is associated with deafness, has not been as thoroughly investigated in the adult brain as it has in the developing brain. In this study, we examined the brain reorganization induced by auditory deprivation in people with adult-onset deafness and its clinical relevance by measuring glucose metabolism before cochlear implant (CI) surgery. F-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET) scans were performed in 37 postlingually deafened patients during the preoperative workup period, and in 39 normal-hearing (NH) controls. Behavioral CI outcomes were measured at 1 year after implantation using a phoneme identification test with auditory cueing only. In the deaf individuals, areas involved in the auditory pathway such as the inferior colliculus and bilateral superior temporal gyri were hypometabolic compared to the NH controls. The hypometabolism observed in the deaf auditory cortices gradually returned to levels similar to the controls as the duration of deafness increased. However, contrary to our previous findings in congenitally deaf children, this metabolic recovery failed to have a significant prognostic value for the recovery of the speech perception ability in adult CI patients. In a broad occipital area centered on the primary visual cortices, glucose metabolism was higher in the deaf patients than the controls, suggesting that the area had become visually hyperactive for sensory compensation immediately after the onset of deafness. In addition, a negative correlation between the metabolic activity and behavioral speech perception outcomes was observed in the visual association areas. In the medial frontal cortices, cortical metabolism in most patients decreased, but patients who had preserved metabolic activities showed better speech performance. These results suggest that the auditory cortex in people with adult-onset deafness is relatively resistant to cross-modal plasticity, and instead, individual traits in late-stage visual processing and cognitive control seem to be more reliable prognostic markers for adult-onset deafness.

Lexical-Access Ability and Cognitive Predictors of Speech Recognition in Noise in Adult Cochlear Implant Users

Not all of the variance in speech-recognition performance of cochlear implant (CI) users can be explained by biographic and auditory factors. In normal-hearing listeners, linguistic and cognitive factors determine most of speech-in-noise performance. The current study explored specifically the influence of visually measured lexical-access ability compared with other cognitive factors on speech recognition of 24 postlingually deafened CI users. Speech-recognition performance was measured with monosyllables in quiet (consonant-vowel-consonant [CVC]), sentences-in-noise (SIN), and digit-triplets in noise (DIN). In addition to a composite variable of lexical-access ability (LA), measured with a lexical-decision test (LDT) and word-naming task, vocabulary size, working-memory capacity (Reading Span test [RSpan]), and a visual analogue of the SIN test (text reception threshold test) were measured. The DIN test was used to correct for auditory factors in SIN thresholds by taking the difference between SIN and DIN: SRT_diff. Correlation analyses revealed that duration of hearing loss (dHL) was related to SIN thresholds. Better working-memory capacity was related to SIN and SRT_diff scores. LDT reaction time was positively correlated with SRT_diff scores. No significant relationships were found for CVC or DIN scores with the predictor variables. Regression analyses showed that together with dHL, RSpan explained 55% of the variance in SIN thresholds. When controlling for auditory performance, LA, LDT, and RSpan separately explained, together with dHL, respectively 37%, 36%, and 46% of the variance in SRT_diff outcome. The results suggest that poor verbal working-memory capacity and to a lesser extent poor lexical-access ability limit speech-recognition ability in listeners with a CI.

The Development of an Interventional Package on "Receptive Vocabulary" For Cochlear Implanted Children

OBJECTIVES

Considering the shortage of language intervention protocols which specifically concentrate on cochlear implanted children and considering the importance of timely language intervention in this group of children, the aim of the present study was to develop an interventional package on "receptive vocabulary" for cochlear implanted children.

MATERIALS & METHODS

By reviewing the literature related to language acquisition theories in normal and language disordered children, as well as literature on production of intervention protocols, especially those for language impaired children, and also considering the normal process of language and speech development in normal children, the first draft of the intervention protocol was prepared. Then, the face and content validity of the intervention protocol was assessed by a Delphi team through three rounds and finally approved.

RESULTS

A language intervention protocol was developed to enhance receptive vocabulary in 12-48 months-old cochlear implanted children, based on cognitive, behavioral and developmental theories. This protocol includes 5 interventional stages: 1-Drilling and Imitation; 2-Modeling; 3-Motor training; 4-Deliberate error correction; 5- Reinstatement and Generalization. Each stage consists of the description of the aims of that stage, a list of techniques, the tools required, the detailed step by step explanation of the intervention, how re-enforcement must take place, and finally the indicators of success which permit to move forward to the next stage.

CONCLUSION

The interventional package produced is believed to facilitate language acquisition in cochlear implanted children, according to expert qualitative assessment and approval. Experimental research is required for verification of this assumption.

Pediatric Auditory Brainstem Implantation: Impact on Audiological Rehabilitation and Tonal Language Development

OBJECTIVE

This is a retrospective review of the impact of an Auditory Brainstem Implant (ABI) on the audiological rehabilitation and tonal language development of pediatric patients with prelingual profound deafness in Hong Kong.

RESULTS

From January 2009 to February 2015, 11 pediatric patients with profound prelingual deafness received an ABI in Hong Kong (age range 1.67-3.75 years). Etiologies included Cochlear Nerve Deficiency in 7, Severe Cochlear Malformations in 2, and Retrocochlear Deafness in 2. All of them were rehabilitated in Cantonese, a dialect of Chinese. Standard pediatric cochlear implant outcome measurements were used in this study that comprised of the 7-Sound Detection, Syllable Identification, Vowel Identification, Consonant Identification, Tone Imitation, Tone Production and Speech Perception Category. Audiological rehabilitation and speech development outcomes were reviewed. Age-matched outcomes of pediatric cochlear implant users were used for comparisons.

CONCLUSION

Encouraging results of speech development were found, especially with continued use of the ABI. There was considerable variation in outcomes. Children with coexisting developmental and nonauditory cognitive disabilities did not perform as well. Auditory brainstem implantation is a safe and beneficial treatment for profound prelingual deafness in Cantonese-speaking pediatric patients.

Improving oral sentence production in children with cochlear implants: effects of equivalence-based instruction and matrix training

ᅟ: Children who use cochlear implants (CI) and who are readers usually produce more accurate speech in response to text than to pictures. Equivalence-based instruction (EBI) can be a route to establish functional interdependence between these verbal operants. The present study investigated whether children with CI who read would improve speech accuracy when tacting pictures of scenes after EBI that included dictated sentences, pictures of scenes, and printed sentences. This study evaluated whether teaching verbal relations to diagonal sentences from a matrix with subject-verb-object combinations promoted recombinative generalization to untrained sentences. Participants were three children with CI with a more accurate speech when reading print than when tacting pictures of scenes. They were taught to select pictures of scenes in response to dictated sentences (AB) by matching-to-sample (MTS) and to construct printed sentences in response to dictated sentences (AE) by constructed-response-matching-to-sample (CRMTS). Speech production in response to print (CD) and in response to pictures of scenes (BD) were probed for both trained and untrained sentences, using a multiple baseline design across participants. All participants learned the trained relations, showed emergence of derived relations, and improved speech accuracy when tacting pictures of scenes. They were able to recombine sentence components and tact novel pictures using untrained sentences from the matrix. These results indicate that speech accuracy and generative sentence production can be improved in children with CI from interventions that incorporate EBI and matrix training. TRIAL REGISTRATION: CAAE#01454412.0.0000.5441 registered 01/29/2013.

Non-native listeners' recognition of high-variability speech using PRESTO

BACKGROUND

Natural variability in speech is a significant challenge to robust successful spoken word recognition. In everyday listening environments, listeners must quickly adapt and adjust to multiple sources of variability in both the signal and listening environments. High-variability speech may be particularly difficult to understand for non-native listeners, who have less experience with the second language (L2) phonological system and less detailed knowledge of sociolinguistic variation of the L2.

PURPOSE

The purpose of this study was to investigate the effects of high-variability sentences on non-native speech recognition and to explore the underlying sources of individual differences in speech recognition abilities of non-native listeners.

RESEARCH DESIGN

Participants completed two sentence recognition tasks involving high-variability and low-variability sentences. They also completed a battery of behavioral tasks and self-report questionnaires designed to assess their indexical processing skills, vocabulary knowledge, and several core neurocognitive abilities.

STUDY SAMPLE

Native speakers of Mandarin (n = 25) living in the United States recruited from the Indiana University community participated in the current study. A native comparison group consisted of scores obtained from native speakers of English (n = 21) in the Indiana University community taken from an earlier study.

DATA COLLECTION AND ANALYSIS

Speech recognition in high-variability listening conditions was assessed with a sentence recognition task using sentences from PRESTO (Perceptually Robust English Sentence Test Open-Set) mixed in 6-talker multitalker babble. Speech recognition in low-variability listening conditions was assessed using sentences from HINT (Hearing In Noise Test) mixed in 6-talker multitalker babble. Indexical processing skills were measured using a talker discrimination task, a gender discrimination task, and a forced-choice regional dialect categorization task. Vocabulary knowledge was assessed with the WordFam word familiarity test, and executive functioning was assessed with the BRIEF-A (Behavioral Rating Inventory of Executive Function - Adult Version) self-report questionnaire. Scores from the non-native listeners on behavioral tasks and self-report questionnaires were compared with scores obtained from native listeners tested in a previous study and were examined for individual differences.

RESULTS

Non-native keyword recognition scores were significantly lower on PRESTO sentences than on HINT sentences. Non-native listeners' keyword recognition scores were also lower than native listeners' scores on both sentence recognition tasks. Differences in performance on the sentence recognition tasks between non-native and native listeners were larger on PRESTO than on HINT, although group differences varied by signal-to-noise ratio. The non-native and native groups also differed in the ability to categorize talkers by region of origin and in vocabulary knowledge. Individual non-native word recognition accuracy on PRESTO sentences in multitalker babble at more favorable signal-to-noise ratios was found to be related to several BRIEF-A subscales and composite scores. However, non-native performance on PRESTO was not related to regional dialect categorization, talker and gender discrimination, or vocabulary knowledge.

CONCLUSIONS

High-variability sentences in multitalker babble were particularly challenging for non-native listeners. Difficulty under high-variability testing conditions was related to lack of experience with the L2, especially L2 sociolinguistic information, compared with native listeners. Individual differences among the non-native listeners were related to weaknesses in core neurocognitive abilities affecting behavioral control in everyday life.

Three challenges for future research on cochlear implants

Cochlear implants (CIs) often work very well for many children and adults with profound sensorineural (SNHL) hearing loss. Unfortunately, while many CI patients display substantial benefits in recognizing speech and understanding spoken language following cochlear implantation, a large number of patients achieve poor outcomes. Understanding and explaining the reasons for poor outcomes following implantation is a very challenging research problem that has received little attention despite the pressing clinical significance. In this paper, we discuss three challenges for future research on CIs. First, we consider the issue of individual differences and variability in outcomes following implantation. At the present time, we still do not have a complete and satisfactory account of the causal underlying factors that are responsible for the enormous individual differences and variability in outcomes. Second, we discuss issues related to the lack of preimplant predictors of outcomes. Very little prospective research has been carried out on the development of preimplant predictors that can be used to reliably identify CI candidates who may be at high risk for a poor outcome following implantation. Other than conventional demographics and hearing history, there are no prognostic tools available to predict speech recognition outcomes after implantation. Finally, we discuss the third challenge - what to do with a CI-user who has a poor outcome. We suggest that new research efforts need to be devoted to studying this neglected clinical population in greater depth to find out why they are doing poorly with their CI and what novel interventions and treatments can be developed to improve their speech recognition outcomes. Using these three challenges as objectives for future research on CIs, we suggest that the field needs to adopt a new narrative grounded in theory and methods from Cognitive Hearing Science and information processing theory. Without knowing which specific biological and neurocognitive factors are responsible for individual differences or understanding the underlying sensory and neurocognitive basis for variability in performance, it is impossible to select a specific approach to habilitation after a deaf adult or child receives a CI. Deaf adults and children who are performing poorly with their CIs are not a homogeneous group and may differ in many different ways from each other, reflecting the dysfunction of multiple brain systems associated with both congenital and acquired deafness. Hearing loss is not only an ear issue, it is also a brain issue too reflecting close links between perception and action and brain, body and world working together as a functionally integrated information processing system to support robust speech recognition and spoken language processing after implantation.

Recognition and Comprehension of "Narrow Focus" by Young Adults With Prelingual Hearing Loss Using Hearing Aids or Cochlear Implants

PURPOSE

The stressed word in a sentence (narrow focus [NF]) conveys information about the intent of the speaker and is therefore important for processing spoken language and in social interactions. The ability of participants with severe-to-profound prelingual hearing loss to comprehend NF has rarely been investigated. The purpose of this study was to assess the recognition and comprehension of NF by young adults with prelingual hearing loss compared with those of participants with normal hearing (NH).

METHOD

The participants included young adults with hearing aids (HA; n = 10), cochlear implants (CI; n = 12), and NH (n = 18). The test material included the Hebrew Narrow Focus Test (Segal, Kaplan, Patael, & Kishon-Rabin, in press), with 3 subtests, which was used to assess the recognition and comprehension of NF in different contexts.

RESULTS

The following results were obtained: (a) CI and HA users successfully recognized the stressed word, with the worst performance for CI; (b) HA and CI comprehended NF less well than NH; and (c) the comprehension of NF was associated with verbal working memory and expressive vocabulary in CI users.

CONCLUSIONS

Most CI and HA users were able to recognize the stressed word in a sentence but had considerable difficulty understanding it. Different factors may contribute to this difficulty, including the memory load during the task itself and linguistic and pragmatic abilities.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.5572792.

Infant-Directed Speech Enhances Attention to Speech in Deaf Infants With Cochlear Implants

Purpose

Both theoretical models of infant language acquisition and empirical studies posit important roles for attention to speech in early language development. However, deaf infants with cochlear implants (CIs) show reduced attention to speech as compared with their peers with normal hearing (NH; Horn, Davis, Pisoni, & Miyamoto, 2005; Houston, Pisoni, Kirk, Ying, & Miyamoto, 2003), which may affect their acquisition of spoken language. The main purpose of this study was to determine (a) whether infant-directed speech (IDS) enhances attention to speech in infants with CIs, as compared with adult-directed speech (ADS), and (b) whether the degree to which infants with CIs pay attention to IDS is associated with later language outcomes.

Method

We tested 46 infants-12 prelingually deaf infants who received CIs before 24 months of age and had 12 months of hearing experience (CI group), 22 hearing experience-matched infants with NH (NH-HEM group), and 12 chronological age-matched infants with NH (NH-CAM group)-on their listening preference in 3 randomized blocks: IDS versus silence, ADS versus silence, and IDS versus ADS. We administered the Preschool Language Scale-Fourth Edition (PLS-4; Zimmerman, Steiner, & Pond, 2002) approximately 18 months after implantation to assess receptive and expressive language skills of infants with CIs.

Results

In the IDS versus silence block, all 3 groups looked significantly longer to IDS than to silence. In the ADS versus silence block, both the NH-HEM and NH-CAM groups looked significantly longer to ADS relative to silence; however, the CI group did not show any preference. In the IDS versus ADS block, whereas both the CI and NH-HEM groups preferred IDS over ADS, the NH-CAM group looked equally long to IDS and ADS. IDS preference quotient among infants with CIs in the IDS versus ADS block was associated with PLS-4 Auditory Comprehension and PLS-4 Expressive Communication measures.

Conclusions

Two major findings emerge: (a) IDS enhances attention to speech in deaf infants with CIs; (b) the degree of IDS preference over ADS relates to language development in infants with CIs. These results support a focus on input in developing intervention strategies to mitigate the effects of hearing loss on language development in infants with hearing loss.

Audiovisual sentence repetition as a clinical criterion for auditory development in Persian-language children with hearing loss

OBJECTIVES

It is important for clinician such as speech-language pathologists and audiologists to develop more efficient procedures to assess the development of auditory, speech and language skills in children using hearing aid and/or cochlear implant compared to their peers with normal hearing. So, the aim of study was the comparison of the performance of 5-to-7-year-old Persian-language children with and without hearing loss in visual-only, auditory-only, and audiovisual presentation of sentence repetition task.

METHODS

The research was administered as a cross-sectional study. The sample size was 92 Persian 5-7 year old children including: 60 with normal hearing and 32 with hearing loss. The children with hearing loss were recruited from Soroush rehabilitation center for Persian-language children with hearing loss in Shiraz, Iran, through consecutive sampling method. All the children had unilateral cochlear implant or bilateral hearing aid. The assessment tool was the Sentence Repetition Test. The study included three computer-based experiments including visual-only, auditory-only, and audiovisual. The scores were compared within and among the three groups through statistical tests in α = 0.05.

RESULTS

The score of sentence repetition task between V-only, A-only, and AV presentation was significantly different in the three groups; in other words, the highest to lowest scores belonged respectively to audiovisual, auditory-only, and visual-only format in the children with normal hearing (P < 0.01), cochlear implant (P < 0.01), and hearing aid (P < 0.01). In addition, there was no significant correlationship between the visual-only and audiovisual sentence repetition scores in all the 5-to-7-year-old children (r = 0.179, n = 92, P = 0.088), but audiovisual sentence repetition scores were found to be strongly correlated with auditory-only scores in all the 5-to-7-year-old children (r = 0.943, n = 92, P = 0.000).

CONCLUSIONS

According to the study's findings, audiovisual integration occurs in the 5-to-7-year-old Persian children using hearing aid or cochlear implant during sentence repetition similar to their peers with normal hearing. Therefore, it is recommended that audiovisual sentence repetition should be used as a clinical criterion for auditory development in Persian-language children with hearing loss.

The Enigma of Poor Performance by Adults With Cochlear Implants

OBJECTIVE

Considerable unexplained variability and large individual differences exist in speech recognition outcomes for postlingually deaf adults who use cochlear implants (CIs), and a sizeable fraction of CI users can be considered "poor performers." This article summarizes our current knowledge of poor CI performance, and provides suggestions to clinicians managing these patients.

METHOD

Studies are reviewed pertaining to speech recognition variability in adults with hearing loss. Findings are augmented by recent studies in our laboratories examining outcomes in postlingually deaf adults with CIs.

RESULTS

In addition to conventional clinical predictors of CI performance (e.g., amount of residual hearing, duration of deafness), factors pertaining to both "bottom-up" auditory sensitivity to the spectro-temporal details of speech, and "top-down" linguistic knowledge and neurocognitive functions contribute to CI outcomes.

CONCLUSIONS

The broad array of factors that contribute to speech recognition performance in adult CI users suggests the potential both for novel diagnostic assessment batteries to explain poor performance, and also new rehabilitation strategies for patients who exhibit poor outcomes. Moreover, this broad array of factors determining outcome performance suggests the need to treat individual CI patients using a personalized rehabilitation approach.

Consequences of Stimulus Type on Higher-Order Processing in Single-Sided Deaf Cochlear Implant Users

Single-sided deaf subjects with a cochlear implant (CI) provide the unique opportunity to compare central auditory processing of the electrical input (CI ear) and the acoustic input (normal-hearing, NH, ear) within the same individual. In these individuals, sensory processing differs between their two ears, while cognitive abilities are the same irrespectively of the sensory input. To better understand perceptual-cognitive factors modulating speech intelligibility with a CI, this electroencephalography study examined the central-auditory processing of words, the cognitive abilities, and the speech intelligibility in 10 postlingually single-sided deaf CI users. We found lower hit rates and prolonged response times for word classification during an oddball task for the CI ear when compared with the NH ear. Also, event-related potentials reflecting sensory (N1) and higher-order processing (N2/N4) were prolonged for word classification (targets versus nontargets) with the CI ear compared with the NH ear. Our results suggest that speech processing via the CI ear and the NH ear differs both at sensory (N1) and cognitive (N2/N4) processing stages, thereby affecting the behavioral performance for speech discrimination. These results provide objective evidence for cognition to be a key factor for speech perception under adverse listening conditions, such as the degraded speech signal provided from the CI.

Can language acquisition be facilitated in cochlear implanted children? Comparison of cognitive and behavioral psychologists’ viewpoints

AIM

To study how language acquisition can be facilitated for cochlear implanted children based on cognitive and behavioral psychology viewpoints?

METHODS

To accomplish this objective, literature related to behaviorist and cognitive psychology prospects about language acquisition were studied and some relevant books as well as Medline, Cochrane Library, Google scholar, ISI web of knowledge and Scopus databases were searched. Among 25 articles that were selected, only 11 met the inclusion criteria and were included in the study. Based on the inclusion criteria, review articles, expert opinion studies, non-experimental and experimental studies that clearly focused on behavioral and cognitive factors affecting language acquisition in children were selected. Finally, the selected articles were appraised according to guidelines of appraisal of medical studies.

RESULTS

Due to the importance of the cochlear implanted child’s language performance, the comparison of behaviorist and cognitive psychology points of view in child language acquisition was done. Since each theoretical basis, has its own positive effects on language, and since the two are not in opposition to one another, it can be said that a set of behavioral and cognitive factors might facilitate the process of language acquisition in children. Behavioral psychologists believe that repetition, as well as immediate reinforcement of child’s language behavior help him easily acquire the language during a language intervention program, while cognitive psychologists emphasize on the relationship between information processing, memory improvement through repetitively using words along with “associated” pictures and objects, motor development and language acquisition.

CONCLUSION

It is recommended to use a combined approach based on both theoretical frameworks while planning a language intervention program.

Development of Open-Set Word Recognition in Children: Speech-Shaped Noise and Two-Talker Speech Maskers

OBJECTIVE

The goal of this study was to establish the developmental trajectories for children's open-set recognition of monosyllabic words in each of two maskers: two-talker speech and speech-shaped noise.

DESIGN

Listeners were 56 children (5 to 16 years) and 16 adults, all with normal hearing. Thresholds for 50% correct recognition of monosyllabic words were measured in a two-talker speech or a speech-shaped noise masker in the sound field using an open-set task. Target words were presented at a fixed level of 65 dB SPL throughout testing, while the masker level was adapted. A repeated-measures design was used to compare the performance of three age groups of children (5 to 7 years, 8 to 12 years, and 13 to 16 years) and a group of adults. The pattern of age-related changes during childhood was also compared between the two masker conditions.

RESULTS

Listeners in all four age groups performed more poorly in the two-talker speech than the speech-shaped noise masker, but the developmental trajectories differed for the two masker conditions. For the speech-shaped noise masker, children's performance improved with age until about 10 years of age, with little systematic child-adult differences thereafter. In contrast, for the two-talker speech masker, children's thresholds gradually improved between 5 and 13 years of age, followed by an abrupt improvement in performance to adult-like levels. Children's thresholds in the two masker conditions were uncorrelated.

CONCLUSIONS

Younger children require a more advantageous signal-to-noise ratio than older children and adults to achieve 50% correct word recognition in both masker conditions. However, children's ability to recognize words appears to take longer to mature and follows a different developmental trajectory for the two-talker speech masker than the speech-shaped noise masker. These findings highlight the importance of considering both age and masker type when evaluating children's masked speech perception abilities.

How Do Deaf Children With and Without Cochlear Implants Manage to Read Sentences: The Key Word Strategy

The aim of this study is to examine the mechanisms used by deaf children with and without cochlear implants (CIs) to read sentences and the linguistic bases (vocabulary and syntax) underlying those reading mechanisms. Previous studies have shown that deaf persons read sentences using the key word strategy (KWS), which consists of identifying some frequent content words and ignoring the function words. The present results show that deaf children, including those wearing CIs from an early age, do use the KWS. It is also shown that this tendency is related with a linguistic deficiency, especially with a poor ability to deal with function words. Furthermore, the age of implantation, and the degree of hearing loss for children without CIs, plays an important role in using the KWS. Some pedagogical consequences of this situation are considered.

Receptive and Expressive Language Skills of Children with Five Years of Experience Using a Cochlear Implant

The language of 7 children who had used a cochlear implant for 5 years was evaluated by means of the Clinical Evaluation of Language Fundamentals-3, the Peabody Picture Vocabulary Test-Revised, and the Expressive Vocabulary Subtest of the Test of Word Knowledge. All subjects demonstrated impaired skills relative to normal-hearing children on 1 or more subtests. Variability in performance occurred between subjects and within subjects across subtests. Strengths in semantic skills were evident compared to weaker syntactic and morphological abilities. The nature of the subjects' language impairments is considered with reference to language delay and specific language impairment. The findings support the need for further evaluation of the rate and course of development of language subskills. Investigation of the influences of information processing, and learning styles and strategies, on children's outcomes is also warranted. These findings have implications for implementation of optimal habilitation and education programs for children with cochlear implants.

Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle

At the present time, there is no question that cochlear implants (CIs) work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of CIs. Although there now is a large body of evidence supporting the "efficacy" of CIs as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the "effectiveness" of CIs in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on CIs. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation.

Generalised EPG treatment effect in a cochlear implant user maintained after 2 years

PURPOSE

The aim of this study was to evaluate speech therapy using electropalatography (EPG) in home training of persistent articulation errors in a cochlear implant user with hearing impairment. There was a particular focus on aspects of maintenance of training effects and possible transfer to connected speech.

METHOD

The participant was a young woman, deaf from early childhood and a cochlear implant user from pre-school age. Treatment effects were evaluated using a single-subject design with multiple measures.

RESULT

Instrumental and perceptual outcome measures showed a clear improvement in the production of the treatment target /ɡ/ in single words and sentences after 4 months of therapy (17 hours). The results were maintained at 3, 6 and 24 months after intervention. Also, /ɡ/ in connected speech, consisting of text reading and spontaneous speech, showed a significant difference between before and after treatment and at long-term follow-up.

CONCLUSION

The results show that EPG used in home training can be an efficient method for treating persistent speech disorders associated with hearing impairment and that the treatment effect appears to maintain.

Facilitating Vocabulary Acquisition of Children With Cochlear Implants Using Electronic Storybooks

The present intervention study explored the word learning of 18 children with cochlear implants in response to E-book instruction. Capitalizing on the multimedia options available in electronic storybooks, the intervention incorporated videos and definitions to provide a vocabulary intervention that includes evidence-based teaching strategies. The extent of the children's word learning was assessed using three assessment tasks: receptive pointing, expressively labeling, and word defining. Children demonstrated greater immediate expressive labeling gains and definition generation gains for words taught in the treatment condition compared to those in the comparison condition. In addition, the children's performance on delayed posttest vocabulary assessments indicated better retention across the expressive vocabulary task for words taught within the treatment condition as compared to the comparison condition. Findings suggest that children with cochlear implants with functional speech perception can benefit from an oral-only multimedia-enhanced intensive vocabulary instruction.

The impact of cochlear implantation on cognition in older adults: a systematic review of clinical evidence

Background

Hearing loss is the third most prevalent chronic condition faced by older adults and has been linked to difficulties in speech perception, activities of daily living, and social interaction. Recent studies have suggested a correlation between severity of hearing loss and an individual’s cognitive function; however, a causative link has yet to be established. One intervention option for management of the most severe to profound hearing loss in older adults is cochlear implantation. We performed a review to determine the status of the literature on the potential influence of cochlear implantation on cognition in the older adult population.

Methods

Over 3800 articles related to cochlear implants, cognition, and older adults were reviewed. Inclusion criteria were as follows: (1) study population including adults > 65 years, (2) intervention with cochlear implantation, and (3) cognition as the primary outcome measure of implantation.

Results

Out of 3,886 studies selected, 3 met inclusion criteria for the review.

Conclusions

While many publications have shown that cochlear implants improve speech perception, social functioning, and overall quality of life, we found no studies in the English literature that have prospectively evaluated changes in cognitive function after implantation with modern cochlear implants in older adults. The state of the current literature reveals a need for further clinical research on the impact of cochlear implantation on cognition in older adults.

The development of auditory perception in children after auditory brainstem implantation

Auditory brainstem implants (ABIs) can provide useful auditory perception and language development in deaf children who are not able to use a cochlear implant (CI). We prospectively followed up a consecutive group of 64 deaf children up to 12 years following ABI surgery. The etiology of deafness in these children was: cochlear nerve aplasia in 49, auditory neuropathy in 1, cochlear malformations in 8, bilateral cochlear postmeningitic ossification in 3, neurofibromatosis type 2 in 2, and bilateral cochlear fractures due to a head injury in 1. Thirty-five children had other congenital nonauditory disabilities. Twenty-two children had previous CIs with no benefit. Fifty-eight children were fitted with the Cochlear 24 ABI device and 6 with the MedEl ABI device, and all children followed the same rehabilitation program. Auditory perceptual abilities were evaluated on the Categories of Auditory Performance (CAP) scale. No child was lost to follow-up, and there were no exclusions from the study. All children showed significant improvement in auditory perception with implant experience. Seven children (11%) were able to achieve the highest score on the CAP test; they were able to converse on the telephone within 3 years of implantation. Twenty children (31.3%) achieved open set speech recognition (CAP score of 5 or greater) and 30 (46.9%) achieved a CAP level of 4 or greater. Of the 29 children without nonauditory disabilities, 18 (62%) achieved a CAP score of 5 or greater with the ABI. All children showed continued improvements in auditory skills over time. The long-term results of ABI surgery reveal significant auditory benefit in most children, and open set auditory recognition in many.

Effects of listeners' working memory and noise on speech intelligibility in dysarthria

The purpose of this study was to investigate the effects of listeners' working memory (WM), types of noise and signal to noise ratios (SNRs) on speech intelligibility in dysarthria. Speech intelligibility was judged by using a word transcription task. A three-way mixed design (2 × 3 × 2) was used with the WM group (high/low group) as a between-subject factor and the types of noise (multi-talker babble/environmental noise) and SNRs (0, +10 and +20 dB) as within-subject factors. The dependent measure was the percentage of correctly transcribed words. The results revealed that the high WM group performed significantly better than the low WM group and listeners performed significantly better at higher levels of SNRs on the speech intelligibility test. The findings of this study suggested that listeners' cognitive abilities and SNRs should be considered as important factors when evaluating speech intelligibility in dysarthria.

Repetitive transcranial magnetic stimulation over left angular gyrus modulates the predictability gain in degraded speech comprehension

Increased neural activity in left angular gyrus (AG) accompanies successful comprehension of acoustically degraded but highly predictable sentences, as previous functional imaging studies have shown. However, it remains unclear whether the left AG is causally relevant for the comprehension of degraded speech. Here, we applied transient virtual lesions to either the left AG or superior parietal lobe (SPL, as a control area) with repetitive transcranial magnetic stimulation (rTMS) while healthy volunteers listened to and repeated sentences with high- versus low-predictable endings and different noise vocoding levels. We expected that rTMS of AG should selectively modulate the predictability gain (i.e., the comprehension benefit from sentences with high-predictable endings) at a medium degradation level. We found that rTMS of AG indeed reduced the predictability gain at a medium degradation level of 4-band noise vocoding (relative to control rTMS of SPL). In contrast, the behavioral perturbation induced by rTMS changed with increased signal quality. Hence, at 8-band noise vocoding, rTMS over AG versus SPL decreased the number of correctly repeated keywords for sentences with low-predictable endings. Together, these results show that the degree of the rTMS interference depended jointly on signal quality and predictability. Our results provide the first causal evidence that the left AG is a critical node for facilitating speech comprehension in challenging listening conditions.