How Hearing Loss and Cochlear Implantation Affect Verbal Working Memory: Evidence From Adolescents.

PURPOSE: Verbal working memory is poorer for children with hearing loss than for peers with normal hearing (NH), even with cochlear implantation and early intervention. Poor verbal working memory can affect academic performance, especially in higher grades, making this deficit a significant problem. This study examined the stability of verbal working memory across middle childhood, tested working memory in adolescents with NH or cochlear implants (CIs), explored whether signal enhancement can improve verbal working memory, and tested two hypotheses proposed to explain the poor verbal working memory of children with hearing loss: (a) Diminished auditory experience directly affects executive functions, including working memory; (b) degraded auditory inputs inhibit children's abilities to recover the phonological structure needed for encoding verbal material into storage. DESIGN: Fourteen-year-olds served as subjects: 55 with NH; 52 with CIs. Immediate serial recall tasks were used to assess working memory. Stimuli consisted of nonverbal, spatial stimuli and four kinds of verbal, acoustic stimuli: nonrhyming and rhyming words, and nonrhyming words with two kinds of signal enhancement: audiovisual and indexical. Analyses examined (a) stability of verbal working memory across middle childhood, (b) differences in verbal and nonverbal working memory, (c) effects of signal enhancement on recall, (d) phonological processing abilities, and (e) source of the diminished verbal working memory in adolescents with cochlear implants. RESULTS: Verbal working memory remained stable across middle childhood. Adolescents across groups performed similarly for nonverbal stimuli, but those with CIs displayed poorer recall accuracy for verbal stimuli; signal enhancement did not improve recall. Poor phonological sensitivity largely accounted for the group effect. CONCLUSIONS: The central executive for working memory is not affected by hearing loss or cochlear implantation. Instead, the phonological deficit faced by adolescents with CIs denigrates the representation in storage and augmenting the signal does not help.

Early otitis media puts children at risk for later auditory and language deficits.

BACKGROUND: Otitis media is a common disorder of early childhood suspected of hindering auditory and language development, but evidence regarding these effects has been contradictory. To examine potential sources of these contradictory past results and explore in more detail the effects of early otitis media on auditory and language development, three specific hypotheses were tested: (1) Variability in children's general attention could influence results, especially for measures of auditory functioning, leading to spurious findings of group differences; (2) Different language skills may be differentially affected, evoking different effects across studies depending on skills assessed; and (3) Different mechanisms might account for the effects of otitis media on acquisition of different language skills, a finding that would affect treatment choices. METHOD: Children 5-10 years old participated: 49 with and 68 without significant histories of otitis media. The auditory function examined was temporal modulation detection, using games designed to maintain children's attention; two additional measures assessed that attention. Measures of lexical knowledge and phonological sensitivity served as the language measures. RESULTS: Sustained attention was demonstrated equally across groups of children with and without histories of otitis media. Children with histories of otitis media performed more poorly than peers without those histories on the auditory measure and on both sets of language measures, but effects were stronger for phonological sensitivity than lexical knowledge. Deficits in temporal modulation detection accounted for variability in phonological sensitivity, but not in lexical knowledge. CONCLUSION: When experimental factors are tightly controlled, evidence emerges showing effects of otitis media early in life on both auditory and language development. Mechanism of effects on language acquisition appear to involve both delayed auditory development and diminished access to the ambient language.

Asynchronies in Auditory and Language Development Obscure Connections to Phonological Deficits in Children.

PURPOSE: For half a century, psycholinguists have been exploring the idea that developmental language disorders may have their roots in suprathreshold auditory dysfunctions, but results are inconclusive. Typical studies focus on relationships between temporal processing abilities and measures of various language skills at the time of testing, a proximal account. This study expanded that focus by testing three novel hypotheses: (a) Spectral processing impairments may be more responsible for language-learning deficits than temporal processing impairments. (b) Phonological sensitivity is likely the specific language skill most strongly affected by auditory (dys)functions. (c) Poor auditory functioning observed at young ages may wholly or partly recover, reducing the magnitude of relationship between those recovered functions and persistent language skills at older ages. METHOD: Sixty-six children (31 boys, 35 girls) 7-10 years of age participated: 36 with typical language and 30 with reading or speech disorder; from this sample two subsamples were designated: younger (7-8 years) and older (9-10 years) children. Four auditory measures were obtained of spectral modulation detection (0.5 and 2.0 cycles per octave) and temporal modulation detection (16 and 64 Hz). Four language measures were obtained, two lexicosyntactic and two phonological. RESULTS: Younger children showed deficits in all auditory skills, but most strongly for spectral modulation detection at 0.5 cycles per octave; that measure was the only one for which older children showed deficits. Spectral modulation detection was the auditory function most strongly correlated with a language skill, and that language skill was phonological sensitivity. CONCLUSIONS: Early impairments in suprathreshold auditory functions, especially spectral processing, interfere with language acquisition at early stages, especially phonological sensitivity. Although auditory functions can recover to some extent, impairments in language skills persist, indicating that a distal account may more appropriately explain the relationship. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24730128.

Interarticulator Speech Coordination: Timing Is of the Essence.

PURPOSE: In skilled speech production, sets of articulators, such as the jaw, tongue, and lips, work cooperatively to achieve task-specific movement goals, despite rampant contextual variation. Efforts to understand these functional units, termed coordinative structures, have focused on identifying the essential control parameters responsible for allowing articulators to achieve these goals, with some research focusing on temporal parameters (relative timing of movements) and other research focusing on spatiotemporal parameters (phase angle of movement onset for one articulator, relative to another). Here, both types of parameters were investigated and compared in detail. METHOD: Ten talkers recorded nonsense, disyllabic /tV#Cat/ utterances using electromagnetic articulography, with alternative V (/ɑ/-/ɛ/) and C (/t/-/d/), across variation in rate (fast-slow) and stress (first syllable stressed-unstressed). Two measures were obtained: (a) the timing of tongue-tip raising onset for medial C, relative to jaw opening-closing cycles and (b) the angle of tongue-tip raising onset, relative to the jaw phase plane. RESULTS: Results showed that any manipulation that shortened the jaw opening-closing cycle reduced both the relative timing and phase angle of the tongue-tip movement onset, but relative timing of tongue-tip movement onset scaled more consistently with jaw opening-closing across rate and stress variation. CONCLUSION: These findings suggest the existence of an intrinsic timing mechanism (or "central clock") that is the primary control parameter for coordinative structures, with online compensation then allowing these structures to achieve their goals spatially. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.22144259.

Recognition of Sentences With Complex Syntax in Speech Babble by Adolescents With Normal Hearing or Cochlear Implants.

PURPOSE: General language abilities of children with cochlear implants have been thoroughly investigated, especially at young ages, but far less is known about how well they process language in real-world settings, especially in higher grades. This study addressed this gap in knowledge by examining recognition of sentences with complex syntactic structures in backgrounds of speech babble by adolescents with cochlear implants, and peers with normal hearing. DESIGN: Two experiments were conducted. First, new materials were developed using young adults with normal hearing as the normative sample, creating a corpus of sentences with controlled, but complex syntactic structures presented in three kinds of babble that varied in voice gender and number of talkers. Second, recognition by adolescents with normal hearing or cochlear implants was examined for these new materials and for sentence materials used with these adolescents at younger ages. Analyses addressed three objectives: (1) to assess the stability of speech recognition across a multiyear age range, (2) to evaluate speech recognition of sentences with complex syntax in babble, and (3) to explore how bottom-up and top-down mechanisms account for performance under these conditions. RESULTS: Results showed: (1) Recognition was stable across the ages of 10-14 years for both groups. (2) Adolescents with normal hearing performed similarly to young adults with normal hearing, showing effects of syntactic complexity and background babble; adolescents with cochlear implants showed poorer recognition overall, and diminished effects of both factors. (3) Top-down language and working memory primarily explained recognition for adolescents with normal hearing, but the bottom-up process of perceptual organization primarily explained recognition for adolescents with cochlear implants. CONCLUSIONS: Comprehension of language in real-world settings relies on different mechanisms for adolescents with cochlear implants than for adolescents with normal hearing. A novel finding was that perceptual organization is a critical factor. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21965228.

The emergence of bifurcated structure in children's language.

Human language is unique among animal communication systems, in part because of its dual patterning in which meaningless phonological units combine to form meaningful words (phonological structure) and words combine to form sentences (lexicosyntactic structure). Although dual patterning is well recognized, its emergence in language development has been scarcely investigated. Chief among questions still unanswered is the extent to which development of these separate structures is independent or interdependent, and what supports acquisition of each level of structure. We explored these questions by examining growth of lexicosyntactic and phonological structure in children with normal hearing (n = 49) and children with hearing loss who use cochlear implants (n = 56). Multiple measures of each kind of structure were collected at 2-year intervals (kindergarten through eighth grade), and used to construct latent scores for each type of structure. Growth curve analysis assessed (a) the relative independence of development for each level of structure; (b) interactions between these two levels of structure in real-time language processing; and (c) contributions to growth of each level of structure made by auditory input, socioeconomic status (as proxy for linguistic experience), and speech motor control. Findings suggested that phonological and lexicosyntactic structure develop largely independently. Auditory input, socioeconomic status, and speech motor control help shape these language structures, with the last two factors exerting stronger effects for children with cochlear implants. Only for children with cochlear implants were interdependencies in real-time processing observed, reflecting compensatory mechanisms likely present to help them handle the disproportionately large phonological deficit they exhibit. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Beyond Recognition: Visual Contributions to Verbal Working Memory.

PURPOSE: It is well recognized that adding the visual to the acoustic speech signal improves recognition when the acoustic signal is degraded, but how that visual signal affects postrecognition processes is not so well understood. This study was designed to further elucidate the relationships among auditory and visual codes in working memory, a postrecognition process. DESIGN: In a main experiment, 80 young adults with normal hearing were tested using an immediate serial recall paradigm. Three types of signals were presented (unprocessed speech, vocoded speech, and environmental sounds) in three conditions (audio-only, audio-video with dynamic visual signals, and audio-picture with static visual signals). Three dependent measures were analyzed: (a) magnitude of the recency effect, (b) overall recall accuracy, and (c) response times, to assess cognitive effort. In a follow-up experiment, 30 young adults with normal hearing were tested largely using the same procedures, but with a slight change in order of stimulus presentation. RESULTS: The main experiment produced three major findings: (a) unprocessed speech evoked a recency effect of consistent magnitude across conditions; vocoded speech evoked a recency effect of similar magnitude to unprocessed speech only with dynamic visual (lipread) signals; environmental sounds never showed a recency effect. (b) Dynamic and static visual signals enhanced overall recall accuracy to a similar extent, and this enhancement was greater for vocoded speech and environmental sounds than for unprocessed speech. (c) All visual signals reduced cognitive load, except for dynamic visual signals with environmental sounds. The follow-up experiment revealed that dynamic visual (lipread) signals exerted their effect on the vocoded stimuli by enhancing phonological quality. CONCLUSIONS: Acoustic and visual signals can combine to enhance working memory operations, but the source of these effects differs for phonological and nonphonological signals. Nonetheless, visual information can support better postrecognition processes for patients with hearing loss.

Disparate Oral and Written Language Abilities in Adolescents With Cochlear Implants: Evidence From Narrative Samples.

PURPOSE: In spite of improvements in language outcomes for children with hearing loss (HL) arising from cochlear implants (CIs), these children can falter when it comes to academic achievement, especially in higher grades. Given that writing becomes increasingly relevant to educational pursuits as children progress through school, this study explored the hypothesis that one challenge facing students with CIs may be written language. METHOD: Participants were 98 eighth graders: 52 with normal hearing (NH) and 46 with severe-to-profound HL who used CIs. Oral and written narratives were elicited and analyzed for morphosyntactic complexity and global narrative features. Five additional measures were collected and analyzed as possible predictors of morphosyntactic complexity: Sentence Comprehension of Syntax, Grammaticality Judgment, Expressive Vocabulary, Forward Digit Span, and Phonological Awareness. RESULTS: For oral narratives, groups performed similarly on both morphosyntactic complexity and global narrative features; for written narratives, critical differences were observed. Compared with adolescents with NH, adolescents with CIs used fewer markers of morphosyntactic complexity and scored lower on several global narrative features in their written narratives. Adolescents with NH outperformed those with CIs on all potential predictor measures, except for Sentence Comprehension of Syntax. Moderately strong relationships were found between predictor variables and individual measures of morphosyntactic complexity, but no comprehensive pattern explained the results. Measures of morphosyntactic complexity and global narrative features were not well correlated, suggesting these measures are assessing separate underlying constructs. CONCLUSIONS: Adolescents with CIs fail to show writing proficiency at high school entry equivalent to that of their peers with NH, which could constrain their academic achievement. Interventions for children with CIs need to target writing skills, and writing assessments should be incorporated into diagnostic assessments. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.17139059.

The contribution of spectral processing to the acquisition of phonological sensitivity by adolescent cochlear implant users and normal-hearing controls.

This study tested the hypotheses that (1) adolescents with cochlear implants (CIs) experience impaired spectral processing abilities, and (2) those impaired spectral processing abilities constrain acquisition of skills based on sensitivity to phonological structure but not those based on lexical or syntactic (lexicosyntactic) knowledge. To test these hypotheses, spectral modulation detection (SMD) thresholds were measured for 14-year-olds with normal hearing (NH) or CIs. Three measures each of phonological and lexicosyntactic skills were obtained and used to generate latent scores of each kind of skill. Relationships between SMD thresholds and both latent scores were assessed. Mean SMD threshold was poorer for adolescents with CIs than for adolescents with NH. Both latent lexicosyntactic and phonological scores were poorer for the adolescents with CIs, but the latent phonological score was disproportionately so. SMD thresholds were significantly associated with phonological but not lexicosyntactic skill for both groups. The only audiologic factor that also correlated with phonological latent scores for adolescents with CIs was the aided threshold, but it did not explain the observed relationship between SMD thresholds and phonological latent scores. Continued research is required to find ways of enhancing spectral processing for children with CIs to support their acquisition of phonological sensitivity.

Electromagnetic articulography appears feasible for assessment of speech motor skills in cochlear-implant users.

The present investigation tested whether there is cross-interference between current electromagnetic articulography (EMA) and cochlear implants (CIs). In an initial experiment, we calibrated EMA sensors with and without a CI present in the EMA field, and measured impedances of all CI electrodes when in and out of the EMA field. In a subsequent experiment, head reference sensor positions were recorded during a speaking task for a normal-hearing talker with and without a CI present in the EMA field. Results revealed minimal interference between the devices, suggesting that EMA is a promising method for assessing speech motor skills in CI users.

When language outgrows them: Comprehension of ambiguous sentences in children with normal hearing and children with hearing loss.

BACKGROUND: In spite of recent gains in language development made by children with hearing loss (HL) as a result of improved auditory prostheses and earlier starts to intervention, these children continue to struggle academically at higher grade levels. We hypothesize that one reason for these incongruent outcomes for language and academics may be that the language demands of school escalate as grade level increases, outstripping the language abilities of children with HL. We tested that hypothesis by examining a higher level skill that is essential for success with academic language, the ability to access multiple interpretations for a sentence. METHOD: 122 children participated at the end of middle school: 56 with normal hearing (NH), 15 with moderate HL who used hearing aids (HAs), and 51 with severe-to-profound HL who used cochlear implants (CIs). Children's abilities to provide more than one interpretation for an ambiguous sentence were assessed. These sentences were ambiguous due either to words having multiple meanings or to syntactic structure that could evoke more than one interpretation. Potential predictors of those abilities were evaluated, including expressive vocabulary, comprehension of syntactic structures, grammaticality judgments, forward digit span, and several audiologic factors. RESULTS: Children with NH performed best, children with CIs performed poorest, and children with HAs performed intermediately to those groups. Children in all groups achieved higher scores on the multiple meanings than on the syntactic structure items. The variables that were associated with performance varied across groups. Audiologic factors did not explain any variability in performance on the ambiguous sentences task for children with HL. CONCLUSIONS: The kind of linguistic flexibility needed to consider more than one interpretation for sentences lacking immediate, real-world context is essential to processing academic language. Children with HL - especially those with severe-to-profound HL who required CIs - showed deficits in this skill, which could contribute to their ongoing academic struggles. Continued language support is needed for these children to allow them to acquire the higher level language skills necessary for success through all of their years in school.

The Devil in the Details Can Be Hard to Spot: Malapropisms and Children With Hearing Loss.

Purpose Better auditory prostheses and earlier interventions have led to remarkable improvements in spoken language abilities for children with hearing loss (HL), but these children often still struggle academically. This study tested a hypothesis for why this may be, proposing that the language of school becomes increasingly disconnected from everyday discourse, requiring greater reliance on bottom-up phonological structure, and children with HL have difficulty recovering that structure from the speech signal. Participants One hundred nineteen fourth graders participated: 48 with normal hearing (NH), 19 with moderate losses who used hearing aids (HAs), and 52 with severe-to-profound losses who used cochlear implants (CIs). Method Three analyses were conducted. #1: Sentences with malapropisms were created, and children's abilities to recognize them were assessed. #2: Factors contributing to those abilities were evaluated, including phonological awareness, phonological processing, vocabulary, verbal working memory, and oral narratives. #3: Teachers' ratings of students' academic competence were obtained, and factors accounting for those ratings were evaluated, including the five listed above, along with word reading and reading comprehension. Results #1: Children with HAs and CIs performed more poorly on malapropism recognition than children with NH, but similarly to each other. #2: All children with HL demonstrated large phonological deficits, but they were especially large for children with CIs. Phonological awareness explained the most variance in malapropism recognition for children with CIs. Vocabulary knowledge explained malapropism recognition for children with NH or HAs, but other factors also contributed. #3: Teachers rated academic competence for children with CIs more poorly than for children with NH or HAs, and variance in those ratings for children with CIs were primarily explained by malapropism scores. Conclusion Children with HL have difficulty recognizing acoustic-phonetic detail in the speech signal, and that constrains their abilities to follow conversations in academic settings, especially if HL is severe enough to require CIs. Supplemental Material https://doi.org/10.23641/asha.13133018.

The Duality of Patterning in Language and its Relationship to Reading in Children with Hearing Loss.

PURPOSE: Duality of Patterning has long been recognized as a unique design feature of human language, and refers to the distinct bi-level structure in which words comprise one level (semantic) and word-internal, phonetic elements comprise the other level (phonological). This report describes this design feature and offers a perspective on why and how it should help shape reading interventions for children with hearing loss. METHOD: Three components comprise this report. Section I offers an overview of Duality of Patterning. Section II reviews results from a longitudinal study illustrating how children with and without hearing loss acquire each level of linguistic structure, and how each level contributes to reading acquisition for each group differently. Section III of this report provides suggestions for how to incorporate this information into interventions for children with hearing loss. RESULTS: Outcomes presented illustrate that semantic structure begins to take form first, with phonological structure following. Semantic structure is related to reading comprehension, and phonological structure is related to word recognition, at least for alphabetic orthographies. Children with hearing loss acquire a less differentiated linguistic system, with structure at the phonological level only partly, or coarsely acquired, and with a lack of clear distinction from the semantic level of structure. Consequently the roles of each level of structure in reading acquisition are less clearly defined for children with hearing loss. CONCLUSION: For children with normal hearing, learning to read is compartmentalized: Emerging sensitivity to phonological structure supports development of word recognition, and semantic-level skills support reading comprehension. Hearing loss diminishes language skills overall, but especially phonological sensitivity. Children with hearing loss, especially those with cochlear implants, must rely on all language skills to learn to read, including both word recognition and reading comprehension, which creates a highly inefficient processing strategy.

Parental Language Input to Children With Hearing Loss: Does It Matter in the End?

Purpose Parental language input (PLI) has reliably been found to influence child language development for children at risk of language delay, but previous work has generally restricted observations to the preschool years. The current study examined whether PLI during the early years explains variability in the spoken language abilities of children with hearing loss at those young ages, as well as later in childhood. Participants One hundred children participated: 34 with normal hearing, 24 with moderate losses who used hearing aids (HAs), and 42 with severe-to-profound losses who used cochlear implants (CIs). Mean socioeconomic status was middle class for all groups. Children with CIs generally received them early. Method Samples of parent-child interactions were analyzed to characterize PLI during the preschool years. Child language abilities (CLAs) were assessed at 48 months and 10 years of age. Results No differences were observed across groups in how parents interacted with their children. Nonetheless, strong differences across groups were observed in the effects of PLI on CLAs at 48 months of age: Children with normal hearing were largely resilient to their parents' language styles. Children with HAs were most influenced by the amount of PLI. Children with CIs were most influenced by PLI that evoked child language and modeled more complex versions. When potential influences of preschool PLI on CLAs at 10 years of age were examined, those effects at preschool were replicated. When mediation analyses were performed, however, it was found that the influences of preschool PLI on CLAs at 10 years of age were partially mediated by CLAs at preschool. Conclusion PLI is critical to the long-term spoken language abilities of children with hearing loss, but the style of input that is most effective varies depending on the severity of risk for delay.

Perception-Production Links in Children's Speech.

Purpose Child phonologists have long been interested in how tightly speech input constrains the speech production capacities of young children, and the question acquires clinical significance when children with hearing loss are considered. Children with sensorineural hearing loss often show differences in the spectral and temporal structures of their speech production, compared to children with normal hearing. The current study was designed to investigate the extent to which this problem can be explained by signal degradation. Method Ten 5-year-olds with normal hearing were recorded imitating 120 three-syllable nonwords presented in unprocessed form and as noise-vocoded signals. Target segments consisted of fricatives, stops, and vowels. Several measures were made: 2 duration measures (voice onset time and fricative length) and 4 spectral measures involving 2 segments (1st and 3rd moments of fricatives and 1st and 2nd formant frequencies for the point vowels). Results All spectral measures were affected by signal degradation, with vowel production showing the largest effects. Although a change in voice onset time was observed with vocoded signals for /d/, voicing category was not affected. Fricative duration remained constant. Conclusions Results support the hypothesis that quality of the input signal constrains the speech production capacities of young children. Consequently, it can be concluded that the production problems of children with hearing loss-including those with cochlear implants-can be explained to some extent by the degradation in the signal they hear. However, experience with both speech perception and production likely plays a role as well.

Children's suffix effects for verbal working memory reflect phonological coding and perceptual grouping.

When listeners recall order of presentation for sequences of unrelated words, recall is most accurate for first and final items. When a speech suffix is appended to the list, however, the advantage for final items is diminished. The usual interpretation is that listeners recover phonological structure from speech signals and use that structure to store items in a working memory buffer; the process of recovering phonological structure for a suffix interrupts that processing for the final list item. Although not mutually exclusive, another hypothesis suggests that perceptual grouping of list items and suffix based on common acoustic structure is necessary for the effect to occur. To evaluate these accounts as well as potential age-related differences, adults and 8-year-old children were asked to recall order of presentation for a closed set of nouns in five suffix conditions: none, auditory go, lipread go, a tone, and a colored circle. Overt articulation was prohibited, but attention to the suffix was mandated. Children's serial recall was generally poorer than that of adults, but patterns across list positions were similar for both age groups. Participants showed stronger effects for speech suffixes than for nonspeech suffixes regardless of whether suffixes were seen or heard, but effects were not restricted to final list items. And although effects of heard and lipread suffixes were similar for early list items, heard speech exerted greater effects on late list items. Outcomes suggest that some effect of heard and lipread speech suffixes arises from their shared phonological structure, but this effect is strongest when perceptual grouping occurs.

Development of Phonological, Lexical, and Syntactic Abilities in Children With Cochlear Implants Across the Elementary Grades.

Purpose: This study assessed phonological, lexical, and morphosyntactic abilities at 6th grade for a group of children previously tested at 2nd grade to address 4 questions: (a) Do children with cochlear implants (CIs) demonstrate deficits at 6th grade? (b) Are those deficits greater, the same, or lesser in magnitude than those observed at 2nd grade? (c) How do the measured skills relate to each other? and (d) How do treatment variables affect outcome measures? Participants: Sixty-two 6th graders (29 with normal hearing, 33 with CIs) participated, all of whom had their language assessed at 2nd grade. Method: Data are reported for 12 measures obtained at 6th grade, assessing phonological, lexical, and morphosyntactic abilities. Between-groups analyses were conducted on 6th-grade measures and the magnitude of observed effects compared with those observed at 2nd grade. Correlational analyses were performed among the measures at 6th grade. Cross-lagged analyses were performed on specific 2nd- and 6th-grade measures of phonological awareness, vocabulary, and literacy to assess factors promoting phonological and lexical development. Treatment effects of age of 1st CI, preimplant thresholds, and bimodal experience were evaluated. Results: Deficits remained fairly consistent in type and magnitude across elementary school. The largest deficits were found for phonological skills and the least for morphosyntactic skills, with lexical skills intermediate. Phonological and morphosyntactic skills were largely independent of each other; lexical skills were moderately related to phonological skills but not morphosyntactic skills. Literacy acquisition strongly promoted both phonological and lexical development. Of the treatment variables, only bimodal experience affected outcomes and did so positively. Conclusions: Congenital hearing loss puts children at continued risk of language deficits, especially for phonologically based skills. Two interventions that appear to ameliorate that risk are providing a period of bimodal stimulation and strong literacy instruction.

Speech Recognition in Noise by Children with and without Dyslexia: How is it Related to Reading?

PURPOSE: Developmental dyslexia is commonly viewed as a phonological deficit that makes it difficult to decode written language. But children with dyslexia typically exhibit other problems, as well, including poor speech recognition in noise. The purpose of this study was to examine whether the speech-in-noise problems of children with dyslexia are related to their reading problems, and if so, if a common underlying factor might explain both. The specific hypothesis examined was that a spectral processing disorder results in these children receiving smeared signals, which could explain both the diminished sensitivity to phonological structure - leading to reading problems - and the speech recognition in noise difficulties. The alternative hypothesis tested in this study was that children with dyslexia simply have broadly based language deficits. PARTICIPANTS: Ninety-seven children between the ages of 7 years; 10 months and 12 years; 9 months participated: 46 with dyslexia and 51 without dyslexia. METHODS: Children were tested on two dependent measures: word reading and recognition in noise with two types of sentence materials: as unprocessed (UP) signals, and as spectrally smeared (SM) signals. Data were collected for four predictor variables: phonological awareness, vocabulary, grammatical knowledge, and digit span. RESULTS: Children with dyslexia showed deficits on both dependent and all predictor variables. Their scores for speech recognition in noise were poorer than those of children without dyslexia for both the UP and SM signals, but by equivalent amounts across signal conditions indicating that they were not disproportionately hindered by spectral distortion. Correlation analyses on scores from children with dyslexia showed that reading ability and speech-in-noise recognition were only mildly correlated, and each skill was related to different underlying abilities. CONCLUSIONS: No substantial evidence was found to support the suggestion that the reading and speech recognition in noise problems of children with dyslexia arise from a single factor that could be defined as a spectral processing disorder. The reading and speech recognition in noise deficits of these children appeared to be largely independent.

Verbal Working Memory in Children With Cochlear Implants.

Purpose: Verbal working memory in children with cochlear implants and children with normal hearing was examined. Participants: Ninety-three fourth graders (47 with normal hearing, 46 with cochlear implants) participated, all of whom were in a longitudinal study and had working memory assessed 2 years earlier. Method: A dual-component model of working memory was adopted, and a serial recall task measured storage and processing. Potential predictor variables were phonological awareness, vocabulary knowledge, nonverbal IQ, and several treatment variables. Potential dependent functions were literacy, expressive language, and speech-in-noise recognition. Results: Children with cochlear implants showed deficits in storage and processing, similar in size to those at second grade. Predictors of verbal working memory differed across groups: Phonological awareness explained the most variance in children with normal hearing; vocabulary explained the most variance in children with cochlear implants. Treatment variables explained little of the variance. Where potentially dependent functions were concerned, verbal working memory accounted for little variance once the variance explained by other predictors was removed. Conclusions: The verbal working memory deficits of children with cochlear implants arise due to signal degradation, which limits their abilities to acquire phonological awareness. That hinders their abilities to store items using a phonological code.

Speech Recognition in Adults With Cochlear Implants: The Effects of Working Memory, Phonological Sensitivity, and Aging.

Purpose: Models of speech recognition suggest that "top-down" linguistic and cognitive functions, such as use of phonotactic constraints and working memory, facilitate recognition under conditions of degradation, such as in noise. The question addressed in this study was what happens to these functions when a listener who has experienced years of hearing loss obtains a cochlear implant. Method: Thirty adults with cochlear implants and 30 age-matched controls with age-normal hearing underwent testing of verbal working memory using digit span and serial recall of words. Phonological capacities were assessed using a lexical decision task and nonword repetition. Recognition of words in sentences in speech-shaped noise was measured. Results: Implant users had only slightly poorer working memory accuracy than did controls and only on serial recall of words; however, phonological sensitivity was highly impaired. Working memory did not facilitate speech recognition in noise for either group. Phonological sensitivity predicted sentence recognition for implant users but not for listeners with normal hearing. Conclusion: Clinical speech recognition outcomes for adult implant users relate to the ability of these users to process phonological information. Results suggest that phonological capacities may serve as potential clinical targets through rehabilitative training. Such novel interventions may be particularly helpful for older adult implant users.