Auditory perceptual processing in people with reading and oral language impairments: current issues and recommendations

Low-Level Auditory Processing Correlates With Language Abilities: An ERP Study Investigating Sequence Learning and Auditory Processing in School-Aged Children

Auditory processing and procedural learning deficits have been associated with language learning difficulties. We investigated the relationship of these skills and school-age language abilities in children with and without a history of late talking using auditory event related potentials (ERPs). Late talking (i.e., slow early language development) increases the risk of persistent language difficulties, but its causes remain unknown. Participants in this study were children with varying language abilities (n = 60). Half of the participants (n = 30) had a history of late talking. We measured procedural learning by manipulating the predictability of sine tone stimuli in a passive auditory ERP paradigm. Auditory processing was tested by examining how the presence of noise (increasing perceptual demands) affected the ERPs. Contrary to our hypotheses on auditory processing and language development, the effect of noise on ERPs did not correlate with school-age language abilities in children with or without a history of late talking. Our paradigm failed to reveal interpretable effects of predictability leaving us unable to assess the effects of procedural learning. However, better language abilities were related to weaker responses in a 75-175 ms time window, and stronger responses in a 150-250 ms time window. We suggest that the weak early responses in children with better language ability reflect efficient processing of low-level auditory information, allowing deeper processing of later, high-level auditory information. We assume that these differences reflect variation in brain maturation between individuals with varying language abilities.

The role of suprathreshold auditory processing abilities in children with specific learning disorder

OBJECTIVE

To assess the suprathreshold auditory processing and speech recognition abilities in noise in children with specific learning disorder (SLD).

METHODS

A group of twenty-five children diagnosed with SLD and a control group of twenty-five neuro-typical children were included in the study. All the participants were between 6-11 years old. To evaluate suprathreshold auditory processing abilities, the participants were given the Temporal Fine Structure (TFS) Sensitivity Test and the Temporal Envelope (TE) Sensitivity Test, as well as the Consonant Identification Test, was administered to evaluate speech recognition ability in noise. In addition, the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) intelligence test was applied to children with SLD, and the relationship between WISC-IV intelligence test scores in different skills and suprathreshold auditory processing and speech recognition abilities in noise was investigated.

RESULTS

Significant differences were found between children diagnosed with SLD and neuro-typical children in terms of suprathreshold auditory processing tasks and speech recognition in noise. Additionally, no correlation was found between suprathreshold auditory processing tasks, speech recognition in noise, and intelligence tests.

CONCLUSION

Suprathreshold auditory processing and speech recognition abilities in noise were found to be affected in children with SLD. A holistic evaluation including a multidisciplinary approach that includes suprathreshold auditory processing abilities is required for children diagnosed with SLD.

Auditory steady state responses elicited by silent gaps embedded within a broadband noise

Background

Auditory temporal processing plays an important role in speech comprehension. Usually, behavioral tests that require subjects to detect silent gaps embedded within a continuous sound are used to assess the ability of auditory temporal processing in humans. To evaluate auditory temporal processing objectively, the present study aimed to measure the auditory steady state responses (ASSRs) elicited by silent gaps of different lengths embedded within a broadband noise. We presented a broadband noise with 40-Hz silent gaps of 3.125, 6.25, and 12.5 ms.

Results

The 40-Hz silent gaps of 3.125, 6.25, and 12.5 ms elicited clear ASSRs. Longer silent gaps elicited larger ASSR amplitudes and ASSR phases significantly differed between conditions.

Conclusion

The 40 Hz gap-evoked ASSR contributes to our understanding of the neural mechanisms underlying auditory temporal processing and may lead to the development of objective measures of auditory temporal acuity in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12868-022-00712-0.

Naturalistic Use of Aspect Morphology in Deaf and Hard-of-Hearing Children

Grammatical morphology often links small acoustic forms to abstract semantic domains. Deaf and hard-of-hearing (DHH) children have reduced access to the acoustic signal and frequently have delayed acquisition of grammatical morphology (e.g., Tomblin, Harrison, Ambrose, Walker, Oleson & Moeller, 2015). This study investigated the naturalistic use of aspectual morphology in DHH children to determine if they organize this semantic domain as normal hearing (NH) children have been found to do. Thirty DHH children (M = 6;8) and 29 NH children (M = 5;11) acquiring English participated in a free-play session and their tokens of perfective (simple past) and imperfective (-ing) morphology were coded for the lexical aspect of the predicate they marked. Both groups showed established prototype effects, favoring perfective + telic and imperfective + atelic pairings over perfective + atelic and perfective + atelic ones. Thus, despite reduced access to the acoustic signal, this DHH group was unimpaired for aspectual organization.

Speech Perception in Noise Predicts Oral Narrative Comprehension in Children With Developmental Language Disorder

We examined the relative contribution of auditory processing abilities (tone perception and speech perception in noise) after controlling for short-term memory capacity and vocabulary, to narrative language comprehension in children with developmental language disorder. Two hundred and sixteen children with developmental language disorder, ages 6 to 9 years (Mean = 7; 6), were administered multiple measures. The dependent variable was children's score on the narrative comprehension scale of the Test of Narrative Language. Predictors were auditory processing abilities, phonological short-term memory capacity, and language (vocabulary) factors, with age, speech perception in quiet, and non-verbal IQ as covariates. Results showed that narrative comprehension was positively correlated with the majority of the predictors. Regression analysis suggested that speech perception in noise contributed uniquely to narrative comprehension in children with developmental language disorder, over and above all other predictors; however, tone perception tasks failed to explain unique variance. The relative importance of speech perception in noise over tone-perception measures for language comprehension reinforces the need for the assessment and management of listening in noise deficits and makes a compelling case for the functional implications of complex listening situations for children with developmental language disorder.

The Influence of the Psychophysical Assessment Paradigm on Pitch Discrimination for Adults (and a Pilot Sample of Children)

Pitch discrimination ability has been of research interest due to its potential relationship to language and literacy. However, assessment protocols for pitch discrimination have varied widely. Prior studies with both children and adults have produced conflicting performance findings across different pitch discrimination research paradigms, though they have consistently shown that discrimination accuracy is based on the psychophysical assessment method applied. In the present study, we examined pitch discrimination performance among convenience samples of 19 adult women and ten female children across six different adaptive psychophysical measurement conditions. We found pitch discrimination performance in both groups to be impacted by the measurement paradigm such that, while adults exhibited significantly better discrimination thresholds than did children, the pattern of performance across the six conditions was similar for both the adults and the children.

Overnight consolidation of speech sounds predicts decoding ability in skilled adult readers

PURPOSE

Phonological representations are important for reading. In the current work, we examine the relationship between speech-perceptual memory encoding and consolidation to reading ability in skilled adult readers.

METHOD

Seventy-three young adults (age 18-24) were first tested in their word and nonword reading ability, and then trained in the late evening to identify an unfamiliar speech sound contrast (Hindi retroflex-dental). Participants were assessed in their ability to perceive the target contrast immediately before training, after training, and 12 hours later.

RESULTS

While perceptual performance on the target at any time point was unassociated with reading ability, overnight changes to the post-training perceptual ability over the 12-hour delay was significantly associated with nonword reading (i.e. decoding) ability, but not real-word reading.

CONCLUSION

These results provide preliminary support for the hypothesis that individual differences in memory processes that update phonological representations following acoustic-phonetic exposure relate to decoding performance, including in adulthood.

Auditory Sensory Processing and Phonological Development in High IQ and Exceptional Readers, Typically Developing Readers, and Children With Dyslexia: A Longitudinal Study

Phonological difficulties characterize children with developmental dyslexia across languages, but whether impaired auditory processing underlies these phonological difficulties is debated. Here the causal question is addressed by exploring whether individual differences in sensory processing predict the development of phonological awareness in 86 English-speaking lower- and middle-class children aged 8 years in 2005 who had dyslexia, or were age-matched typically developing children, some with exceptional reading/high IQ. The predictive relations between auditory processing and phonological development are robust for this sample even when phonological awareness at Time 1 (the autoregressor) is controlled. High reading/IQ does not much impact these relations. The data suggest that basic sensory abilities are significant longitudinal predictors of growth in phonological awareness in children.

A Cortico-Collicular Amplification Mechanism for Gap Detection

Auditory cortex (AC) is necessary for the detection of brief gaps in ongoing sounds, but not for the detection of longer gaps or other stimuli such as tones or noise. It remains unclear why this is so, and what is special about brief gaps in particular. Here, we used both optogenetic suppression and conventional lesions to show that the cortical dependence of brief gap detection hinges specifically on gap termination. We then identified a cortico-collicular gap detection circuit that amplifies cortical gap termination responses before projecting to inferior colliculus (IC) to impact behavior. We found that gaps evoked off-responses and on-responses in cortical neurons, which temporally overlapped for brief gaps, but not long gaps. This overlap specifically enhanced cortical responses to brief gaps, whereas IC neurons preferred longer gaps. Optogenetic suppression of AC reduced collicular responses specifically to brief gaps, indicating that under normal conditions, the enhanced cortical representation of brief gaps amplifies collicular gap responses. Together these mechanisms explain how and why AC contributes to the behavioral detection of brief gaps, which are critical cues for speech perception, perceptual grouping, and auditory scene analysis.

Auditory, Visual, and Cross-Modal Temporal Processing Skills Among Chinese Children With Developmental Dyslexia

The present study examined whether temporal processing (TP) is associated with reading of a non-alphabetic script, that is, Chinese. A total of 126 primary school-aged Chinese children from Taiwan (63 children with dyslexia) completed cross-modal, visual, and auditory temporal order judgment tasks and measures of Chinese reading and literacy-related skills. The results showed that typically developing children and children with dyslexia differed in all TP skills. Structural equation modeling indicated that cross-modal TP contributed independently to character recognition in the entire sample if the significant effects of phonological awareness, orthographic knowledge, and rapid automatized naming were considered. The multi-sample analysis showed that TP did not predict reading in the typical group after controlling for literacy-related skills, but visual and cross-modal TP skills independently contributed to reading in the group with dyslexia in addition to literacy-related skills. Finally, the path analysis indicated that in the typical group, separate TP skills affected reading through literacy-related skills, but visual and cross-modal TP skills had direct effects on character reading in the group with dyslexia. These findings suggest that TP is more important for reading in children with dyslexia than in typically developing children, and the roles of TP in dyslexia require further examination.

Training in Temporal Information Processing Ameliorates Phonetic Identification

Many studies revealed a link between temporal information processing (TIP) in a millisecond range and speech perception. Previous studies indicated a dysfunction in TIP accompanied by deficient phonemic hearing in children with specific language impairment (SLI). In this study we concentrate in SLI on phonetic identification, using the voice-onset-time (VOT) phenomenon in which TIP is built-in. VOT is crucial for speech perception, as stop consonants (like /t/ vs. /d/) may be distinguished by an acoustic difference in time between the onsets of the consonant (stop release burst) and the following vibration of vocal folds (voicing). In healthy subjects two categories (voiced and unvoiced) are determined using VOT task. The present study aimed at verifying whether children with SLI indicate a similar pattern of phonetic identification as their healthy peers and whether the intervention based on TIP results in improved performance on the VOT task. Children aged from 5 to 8 years (n = 47) were assigned into two groups: normal children without any language disability (NC, n = 20), and children with SLI (n = 27). In the latter group participants were randomly classified into two treatment subgroups, i.e., experimental temporal training (EG, n = 14) and control non-temporal training (CG, n = 13). The analyzed indicators of phonetic identification were: (1) the boundary location (α) determined as the VOT value corresponding to 50% voicing/unvoicing distinctions; (2) ranges of voiced/unvoiced categories; (3) the slope of identification curve (β) reflecting the identification correctness; (4) percent of voiced distinctions within the applied VOT spectrum. The results indicated similar α values and similar ranges of voiced/unvoiced categories between SLI and NC. However, β in SLI was significantly higher than that in NC. After the intervention, the significant improvement of β was observed only in EG. They achieved the level of performance comparable to that observed in NC. The training-related improvement in CG was non-significant. Furthermore, only in EG the β values in post-test correlated with measures of TIP as well as with phonemic hearing obtained in our previous studies. These findings provide another evidence that TIP is omnipresent in language communication and reflected not only in phonemic hearing but also in phonetic identification.

Response to the Letter to the Editor From Moncrieff (2017) Regarding de Wit et al. (2016), "Characteristics of Auditory Processing Disorders: A Systematic Review"

PURPOSE

The purpose of this letter is to respond to Moncrieff's (2017) letter to the editor, "Response to de Wit et al., 2016, 'Characteristics of Auditory Processing Disorders: A Systematic Review,'" published in May 2017 by the Journal of Speech, Language, and Hearing Research.

CONCLUSION

We believe that our original conclusions are valid given the limited evidence that is currently available about the etiology of auditory processing disorders (APD). The focus of our systematic review was to identify the characteristics of children with a diagnosis of APD or a suspicion of APD. The results of our study showed that the characteristics of these children are not specific or limited to the auditory modality but are multimodal instead. In our view, it is incorrect to use the diagnosis APD, because there is not necessarily a specific auditory deficit in a large group of children suffering from listening difficulties. Before we start using any new diagnoses, a better insight into how bottom-up and top-down processes are precisely involved in listening needs to be developed. In addition, more insight is needed with respect to the similarities and differences between the different developmental disorders of children.

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.

Pitch discrimination associated with phonological awareness: Evidence from congenital amusia

Research suggests that musical skills are associated with phonological abilities. To further investigate this association, we examined whether phonological impairments are evident in individuals with poor music abilities. Twenty individuals with congenital amusia and 20 matched controls were assessed on a pure-tone pitch discrimination task, a rhythm discrimination task, and four phonological tests. Amusic participants showed deficits in discriminating pitch and discriminating rhythmic patterns that involve a regular beat. At a group level, these individuals performed similarly to controls on all phonological tests. However, eight amusics with severe pitch impairment, as identified by the pitch discrimination task, exhibited significantly worse performance than all other participants in phonological awareness. A hierarchical regression analysis indicated that pitch discrimination thresholds predicted phonological awareness beyond that predicted by phonological short-term memory and rhythm discrimination. In contrast, our rhythm discrimination task did not predict phonological awareness beyond that predicted by pitch discrimination thresholds. These findings suggest that accurate pitch discrimination is critical for phonological processing. We propose that deficits in early-stage pitch discrimination may be associated with impaired phonological awareness and we discuss the shared role of pitch discrimination for processing music and speech.

Auditory perception and word recognition in Cantonese-Chinese speaking children with and without Specific Language Impairment

Auditory processing and spoken word recognition difficulties have been observed in Specific Language Impairment (SLI), raising the possibility that auditory perceptual deficits disrupt word recognition and, in turn, phonological processing and oral language. In this study, fifty-seven kindergarten children with SLI and fifty-three language-typical age-matched controls were assessed with a speech-gating task to measure spoken word recognition, psychophysical tasks to measure auditory Frequency Modulation (FM) detection and Frequency Discrimination (FD), and standardized psychometric tests of phonological processing and oral language. As a group, children with SLI took significantly longer than language-typical controls to recognize words with high neighborhood density, perhaps reflecting subpar phonological representations. FM, but not FD, was significantly worse in SLI. However, while both poorer speech-gating performance and poorer auditory thresholds (FM) were evident in SLI, spoken word recognition did not mediate any relation between auditory perception and either phonological processing or oral language.

The Tale is in the Tail: An Alternative Hypothesis for Psychophysical Performance Variability in Dyslexia

Dyslexic groups have been reported to display poorer mean performance than groups of normal readers on a variety of psychophysical tasks. However, inspection of the distribution of individual scores for each group typically reveals that the majority of dyslexic observers actually perform within the normal range. Differences between group means often reflect the influence of a small number of dyslexic individuals who perform very poorly. While such findings are typically interpreted as evidence for specific perceptual deficiencies in dyslexia, caution in this approach is necessary. In this study we examined how general difficulties with task completion might manifest themselves in group psychophysical studies. Simulations of the effect of errant or inattentive trials on performance produced patterns of variability similar to those seen in dyslexic groups. Additionally, predicted relationships between the relative variability in dyslexic and control groups, and the magnitude of group differences bore close resemblance to the outcomes of a meta-analysis of empirical studies. These results suggest that general, nonsensory difficulties may underlie the poor performance of dyslexic groups on many psychophysical tasks. Implications and recommendations for future research are discussed.

Auditory Processing in Specific Language Impairment (SLI): Relations With the Perception of Lexical and Phrasal Stress

PURPOSE

We investigated whether impaired acoustic processing is a factor in developmental language disorders. The amplitude envelope of the speech signal is known to be important in language processing. We examined whether impaired perception of amplitude envelope rise time is related to impaired perception of lexical and phrasal stress in children with specific language impairment (SLI).

METHOD

Twenty-two children aged between 8 and 12 years participated in this study. Twelve had SLI; 10 were typically developing controls. All children completed psychoacoustic tasks measuring rise time, intensity, frequency, and duration discrimination. They also completed 2 linguistic stress tasks measuring lexical and phrasal stress perception.

RESULTS

The SLI group scored significantly below the typically developing controls on both stress perception tasks. Performance on stress tasks correlated with individual differences in auditory sensitivity. Rise time and frequency thresholds accounted for the most unique variance. Digit Span also contributed to task success for the SLI group.

CONCLUSIONS

The SLI group had difficulties with both acoustic and stress perception tasks. Our data suggest that poor sensitivity to amplitude rise time and sound frequency significantly contributes to the stress perception skills of children with SLI. Other cognitive factors such as phonological memory are also implicated.

Mismatch negativity in children with specific language impairment and auditory processing disorder

Introduction

Mismatch negativity, an electrophysiological measure, evaluates the brain's capacity to discriminate sounds, regardless of attentional and behavioral capacity. Thus, this auditory event-related potential is promising in the study of the neurophysiological basis underlying auditory processing.

Objective

To investigate complex acoustic signals (speech) encoded in the auditory nervous system of children with specific language impairment and compare with children with auditory processing disorders and typical development through the mismatch negativity paradigm.

Methods

It was a prospective study. 75 children (6–12 years) participated in this study: 25 children with specific language impairment, 25 with auditory processing disorders, and 25 with typical development. Mismatch negativity was obtained by subtracting from the waves obtained by the stimuli /ga/ (frequent) and /da/ (rare). Measures of mismatch negativity latency and two amplitude measures were analyzed.

Results

It was possible to verify an absence of mismatch negativity in 16% children with specific language impairment and 24% children with auditory processing disorders. In the comparative analysis, auditory processing disorders and specific language impairment showed higher latency values and lower amplitude values compared to typical development.

Conclusion

These data demonstrate changes in the automatic discrimination of crucial acoustic components of speech sounds in children with specific language impairment and auditory processing disorders. It could indicate problems in physiological processes responsible for ensuring the discrimination of acoustic contrasts in pre-attentional and pre-conscious levels, contributing to poor perception.

Age, dyslexia subtype and comorbidity modulate rapid auditory processing in developmental dyslexia

The nature of Rapid Auditory Processing (RAP) deficits in dyslexia remains debated, together with the specificity of the problem to certain types of stimuli and/or restricted subgroups of individuals. Following the hypothesis that the heterogeneity of the dyslexic population may have led to contrasting results, the aim of the study was to define the effect of age, dyslexia subtype and comorbidity on the discrimination and reproduction of non-verbal tone sequences. Participants were 46 children aged 8–14 (26 with dyslexia, subdivided according to age, presence of a previous language delay, and type of dyslexia). Experimental tasks were a Temporal Order Judgment (TOJ) (manipulating tone length, ISI and sequence length), and a Pattern Discrimination Task. Dyslexic children showed general RAP deficits. Tone length and ISI influenced dyslexic and control children's performance in a similar way, but dyslexic children were more affected by an increase from 2 to 5 sounds. As to age, older dyslexic children's difficulty in reproducing sequences of 4 and 5 tones was similar to that of normally reading younger (but not older) children. In the analysis of subgroup profiles, the crucial variable appears to be the advantage, or lack thereof, in processing long vs. short sounds. Dyslexic children with a previous language delay obtained the lowest scores in RAP measures, but they performed worse with shorter stimuli, similar to control children, while dyslexic-only children showed no advantage for longer stimuli. As to dyslexia subtype, only surface dyslexics improved their performance with longer stimuli, while phonological dyslexics did not. Differential scores for short vs. long tones and for long vs. short ISIs predict non-word and word reading, respectively, and the former correlate with phonemic awareness. In conclusion, the relationship between non-verbal RAP, phonemic skills and reading abilities appears to be characterized by complex interactions with subgroup characteristics.

Normative topographic ERP analyses of speed of speech processing and grammar before and after grammatical treatment

Typically developing (TD) preschoolers and age-matched preschoolers with specific language impairment (SLI) received event-related potentials (ERPs) to four monosyllabic speech sounds prior to treatment and, in the SLI group, after 6 months of grammatical treatment. Before treatment, the TD group processed speech sounds faster than the SLI group. The SLI group increased the speed of their speech processing after treatment. Posttreatment speed of speech processing predicted later impairment in comprehending phrase elaboration in the SLI group. During the treatment phase, change in speed of speech processing predicted growth rate of grammar in the SLI group.

From temporal processing to developmental language disorders: mind the gap

The 'rapid temporal processing' and the 'temporal sampling framework' hypotheses have been proposed to account for the deficits in language and literacy development seen in specific language impairment and dyslexia. This paper reviews these hypotheses and concludes that the proposed causal chains between the presumed auditory processing deficits and the observed behavioural manifestation of the disorders are vague and not well established empirically. Several problems and limitations are identified. Most data concern correlations between distantly related tasks, and there is considerable heterogeneity and variability in performance as well as concerns about reliability and validity. Little attention is paid to the distinction between ostensibly perceptual and metalinguistic tasks or between implicit and explicit modes of performance, yet measures are assumed to be pure indicators of underlying processes or representations. The possibility that diagnostic categories do not refer to causally and behaviourally homogeneous groups needs to be taken seriously, taking into account genetic and neurodevelopmental studies to construct multiple-risk models. To make progress in the field, cognitive models of each task must be specified, including performance domains that are predicted to be deficient versus intact, testing multiple indicators of latent constructs and demonstrating construct reliability and validity.

Early neural disruption and auditory processing outcomes in rodent models: implications for developmental language disability

Most researchers in the field of neural plasticity are familiar with the "Kennard Principle," which purports a positive relationship between age at brain injury and severity of subsequent deficits (plateauing in adulthood). As an example, a child with left hemispherectomy can recover seemingly normal language, while an adult with focal injury to sub-regions of left temporal and/or frontal cortex can suffer dramatic and permanent language loss. Here we present data regarding the impact of early brain injury in rat models as a function of type and timing, measuring long-term behavioral outcomes via auditory discrimination tasks varying in temporal demand. These tasks were created to model (in rodents) aspects of human sensory processing that may correlate-both developmentally and functionally-with typical and atypical language. We found that bilateral focal lesions to the cortical plate in rats during active neuronal migration led to worse auditory outcomes than comparable lesions induced after cortical migration was complete. Conversely, unilateral hypoxic-ischemic (HI) injuries (similar to those seen in premature infants and term infants with birth complications) led to permanent auditory processing deficits when induced at a neurodevelopmental point comparable to human "term," but only transient deficits (undetectable in adulthood) when induced in a "preterm" window. Convergent evidence suggests that regardless of when or how disruption of early neural development occurs, the consequences may be particularly deleterious to rapid auditory processing (RAP) outcomes when they trigger developmental alterations that extend into subcortical structures (i.e., lower sensory processing stations). Collective findings hold implications for the study of behavioral outcomes following early brain injury as well as genetic/environmental disruption, and are relevant to our understanding of the neurologic risk factors underlying developmental language disability in human populations.

Lexical spelling in children and adolescents with specific language impairment: variations with the writing situation

The goal of this study was to compare the lexical spelling performance of children and adolescents with specific language impairment (SLI) in two contrasting writing situations: a dictation of isolated words (a classic evaluative situation) and a narrative of a personal event (a communicative situation). Twenty-four children with SLI and 48 typically developing children participated in the study, split into two age groups: 7-11 and 12-18 years of age. Although participants with SLI made more spelling errors per word than typically developing participants of the same chronological age, there was a smaller difference between the two groups in the narratives than in the dictations. Two of the findings are particularly noteworthy: (1) Between 12 and 18 years of age, in communicative narration, the number of spelling errors of the SLI group was not different from that of the typically developing group. (2) In communicative narration, the participants with SLI did not make specific spelling errors (phonologically unacceptable), contrary to what was shown in the dictation. From an educational perspective or that of a remediation program, it must be stressed that the communicative narration provides children-and especially adolescents-with SLI an opportunity to demonstrate their improved lexical spelling abilities. Furthermore, the results encourage long-term lexical spelling education, as adolescents with SLI continue to show improvement between 12 and 18 years of age.

Basic auditory processing deficits in dyslexia: systematic review of the behavioral and event-related potential/ field evidence

A review of research that uses behavioral, electroencephalographic, and/or magnetoencephalographic methods to investigate auditory processing deficits in individuals with dyslexia is presented. Findings show that measures of frequency, rise time, and duration discrimination as well as amplitude modulation and frequency modulation detection were most often impaired in individuals with dyslexia. Less consistent findings were found for intensity and gap perception. Additional factors that mediate auditory processing deficits in individuals with dyslexia and their implications are discussed.

Psychophysical estimates of frequency discrimination: more than just limitations of auditory processing

Efficient auditory processing is hypothesized to support language and literacy development. However, behavioral tasks used to assess this hypothesis need to be robust to non-auditory specific individual differences. This study compared frequency discrimination abilities in a heterogeneous sample of adults using two different psychoacoustic task designs, referred to here as: 2I_6A_X and 3I_2AFC designs. The role of individual differences in nonverbal IQ (NVIQ), socioeconomic status (SES) and musical experience in predicting frequency discrimination thresholds on each task were assessed using multiple regression analyses. The 2I_6A_X task was more cognitively demanding and hence more susceptible to differences specifically in SES and musical training. Performance on this task did not, however, relate to nonword repetition ability (a measure of language learning capacity). The 3I_2AFC task, by contrast, was only susceptible to musical training. Moreover, thresholds measured using it predicted some variance in nonword repetition performance. This design thus seems suitable for use in studies addressing questions regarding the role of auditory processing in supporting language and literacy development.

Altered neuronal response during rapid auditory processing and its relation to phonological processing in prereading children at familial risk for dyslexia

Developmental dyslexia (DD) is a learning disability affecting 5-17% of children. Although researchers agree that DD is characterized by deficient phonological processing (PP), its cause is debated. It has been suggested that altered rapid auditory processing (RAP) may lead to deficient PP in DD and studies have shown deficient RAP in individuals with DD. Functional neuroimaging (fMRI) studies have implicated hypoactivations in left prefrontal brain regions during RAP in individuals with DD. When and how these neuronal alterations evolve remains unknown. In this article, we investigate functional networks during RAP in 28 children with (n = 14) and without (n = 14) a familial risk for DD before reading onset (mean: 5.6 years). Results reveal functional alterations in left-hemispheric prefrontal regions during RAP in prereading children at risk for DD, similar to findings in individuals with DD. Furthermore, activation during RAP in left prefrontal regions positively correlates with prereading measures of PP and with neuronal activation during PP in posterior dorsal and ventral brain areas. Our results suggest that neuronal differences during RAP predate reading instruction and thus are not due to experience-dependent brain changes resulting from DD itself and that there is a functional relationship between neuronal networks for RAP and PP within the prereading brain.

Differential cognitive and perceptual correlates of print reading versus braille reading

The relations between reading, auditory, speech, phonological and tactile spatial processing are investigated in a Dutch speaking sample of blind braille readers as compared to sighted print readers. Performance is assessed in blind and sighted children and adults. Regarding phonological ability, braille readers perform equally well compared to print readers on phonological awareness, better on verbal short-term memory and significantly worse on lexical retrieval. The groups do not differ on speech perception or auditory processing. Braille readers, however, have more sensitive fingers than print readers. Investigation of the relations between these cognitive and perceptual skills and reading performance indicates that in the group of braille readers auditory temporal processing has a longer lasting and stronger impact not only on phonological abilities, which have to satisfy the high processing demands of the strictly serial language input, but also directly on the reading ability itself. Print readers switch between grapho-phonological and lexical reading modes depending on the familiarity of the items. Furthermore, the auditory temporal processing and speech perception, which were substantially interrelated with phonological processing, had no direct associations with print reading measures.

Gaps-in-noise (GIN©) test results in children with and without reading disabilities and phonological processing deficits

OBJECTIVE

To determine if the gaps-in-noise (GIN(©)) test could differentiate children with dyslexia and significant phonological awareness deficits from a group of children with normal reading skills.

DESIGN

A prospective study of GIN test performance in two groups of children. Participants were administered routine audiological tests, a phonological processing test, and an auditory temporal resolution test (GIN test). Statistical testing was completed to determine if significant differences existed between groups on GIN test results and phonological processing measures, and to examine potential relationships between these test measures. Routine clinical analysis procedures examined the performance of the two groups from a clinical perspective.

STUDY SAMPLE

Participants included 61 children between the ages of 8 years, 1 month and 9 years, 11 months, separated into two groups: children with dyslexia and significant phonological deficits (Group I); normal-reading peers with age-appropriate phonological skills (Group II).

RESULTS

Children in Group I showed longer gap detection (GD) thresholds and lower gap identification scores than did the children in Group II. Results of statistical and clinical testing revealed significant differences between the groups.

CONCLUSION

An auditory temporal processing deficit is a factor to be considered in children presenting with dyslexia and phonological processing disorders.

Probing the neurocognitive trajectories of children's reading skills

Emerging evidence of the high variability in the cognitive skills and deficits associated with reading achievement and dysfunction promotes both a more dimensional view of the risk factors involved, and the importance of discriminating between trajectories of impairment. Here we examined reading and component orthographic and phonological skills alongside measures of cognitive ability and auditory and visual sensory processing in a large group of primary school children between the ages of 7 and 12 years. We identified clusters of children with pseudoword or exception word reading scores at the 10th percentile or below relative to their age group, and a group with poor skills on both tasks. Compared to age-matched and reading-level controls, groups of children with more impaired exception word reading were best described by a trajectory of developmental delay, whereas readers with more impaired pseudoword reading or combined deficits corresponded more with a pattern of atypical development. Sensory processing deficits clustered within both of the groups with putative atypical development: auditory discrimination deficits with poor phonological awareness skills; impairments of visual motion processing in readers with broader and more severe patterns of reading and cognitive impairments. Sensory deficits have been variably associated with developmental impairments of literacy and language; these results suggest that such deficits are also likely to cluster in children with particular patterns of reading difficulty.

Predicting early spelling difficulties in children with specific language impairment: a clinical perspective

This study focused on the precursors of spelling difficulties in first grade for children with specific language impairment (SLI). A sample of 58 second-year kindergartners in The Netherlands was followed until the end of first grade. Linguistic, phonological, orthographic, letter knowledge, memory, and nonverbal-reasoning skills were considered as precursors, as was spelling level at an earlier point in time. Spelling difficulties at the end of first grade were most accurately identified by letter knowledge at the beginning of first grade and word spelling at the middle of first grade. It is concluded that spelling development in children with SLI can be seen as an autocatalytic process in which, without intervention, poor spellers generally remain poor spellers, and good spellers remain good spellers. A focus on early spelling intervention is thus emphasized.

Low-level deficits in beat perception: neither necessary nor sufficient for explaining developmental dyslexia in a consistent orthography

This article reports two different studies examining the theoretical account of low-level deficits in beat perception as an alternative explanation of developmental dyslexia in Greek, an orthographically consistent language. Study I examined the relationship of amplitude rise time and frequency discrimination with measures of phonological processing, working memory, and reading fluency in a large unselected sample of Grade 4 children. Study II examined the presence of beat perception deficits in groups of Grade 2, 4, and 6 children with dyslexia and their chronological age controls. The results provided no evidence to support meaningful associations between beat perception tasks and reading or the theoretical account of beat perception deficits as a sufficient explanation or contributing factor to dyslexia. Implications on the importance of auditory processing in reading in orthographically consistent languages are discussed.

Effect of phonological training in French children with SLI: perspectives on voicing identification, discrimination and categorical perception

The aim of the present study was to investigate the effect of auditory training on voicing perception in French children with specific language impairment (SLI). We used an adaptive discrimination training that was centred across the French phonological boundary (0 ms voice onset time--VOT). One group of nine children with SLI attended eighteen twenty-minute training sessions with feedback, and a control group of nine children with SLI did not receive any training. Identification, discrimination and categorical perception were evaluated before, during and after training as well as one month following the final session. Phonological awareness and vocabulary were also assessed for both groups. The results showed that children with SLI experienced strong difficulties in the identification, discrimination and categorical perception of the voicing continuum prior to training. However, as early as after the first nine training sessions, their performance in the identification and discrimination tasks increased significantly. Moreover, phonological awareness scores improved during training, whereas vocabulary scores remained stable across sessions.

Psychophysical indices of perceptual functioning in dyslexia: A psychometric analysis

An influential causal theory attributes dyslexia to visual and/or auditory perceptual deficits. This theory derives from group differences between individuals with dyslexia and controls on a range of psychophysical tasks, but there is substantial variation, both between individuals within a group and from task to task. We addressed two questions. First, do psychophysical measures have sufficient reliability to assess perceptual deficits in individuals? Second, do different psychophysical tasks measure a common underlying construct? We studied 104 adults with a wide range of reading ability and two comparison groups of 49 dyslexic adults and 41 adults with normal reading, measuring performance on four auditory and two visual tasks. We observed moderate to high test–retest reliability for most tasks. While people with dyslexia were more likely to display poor task performance, we were unable to demonstrate either construct validity for any of the current theories of perceptual deficits or predictive validity for reading ability. We suggest that deficient perceptual task performance in dyslexia may be an associated (and inconsistent) marker of underlying neurological abnormality, rather than being causally implicated in reading difficulties.

Temporal auditory processing at 17 months of age is associated with preliterate language comprehension and later word reading fluency: an ERP study

Dyslexia is heritable and associated with auditory processing deficits. We investigate whether temporal auditory processing is compromised in young children at-risk for dyslexia and whether it is associated with later language and reading skills. We recorded EEG from 17 months-old children with or without familial risk for dyslexia to investigate whether their auditory system was able to detect a temporal change in a tone pattern. The children were followed longitudinally and performed an intelligence- and language development test at ages 4 and 4.5 years. Literacy related skills were measured at the beginning of second grade, and word- and pseudo-word reading fluency were measured at the end of second grade. The EEG responses showed that control children could detect the temporal change as indicated by a mismatch response (MMR). The MMR was not observed in at-risk children. Furthermore, the fronto-central MMR amplitude correlated with preliterate language comprehension and with later word reading fluency, but not with phonological awareness. We conclude that temporal auditory processing differentiates young children at risk for dyslexia from controls and is a precursor of preliterate language comprehension and reading fluency.

Probing the perceptual and cognitive underpinnings of braille reading. An Estonian population study

Similar to many sighted children who struggle with learning to read, a proportion of blind children have specific difficulties related to reading braille which cannot be easily explained. A lot of research has been conducted to investigate the perceptual and cognitive processes behind (impairments in) print reading. Very few studies, however, have aimed for a deeper insight into the relevant perceptual and cognitive processes involved in braille reading. In the present study we investigate the relations between reading achievement and auditory, speech, phonological and tactile processing in a population of Estonian braille reading children and youngsters and matched sighted print readers. Findings revealed that the sequential nature of braille imposes constant decoding and effective recruitment of phonological skills throughout the reading process. Sighted print readers, on the other hand, seem to switch between the use of phonological and lexical processing modes depending on the familiarity, length and structure of the word.

Children with specific language impairment show difficulties in sensory modulation

The purpose of this study is to investigate whether a group of 116 Dutch children with specific language impairment (SLI) shows differences in sensory processing when compared to a control group of age-matched 4-7-year-old typical peers. The Sensory Profile-NL-a standardized questionnaire of 125 items-was completed by caregivers of children in both groups. Children with SLI differed significantly from the control group on all 14 section scores and 4 quadrant scores of the Sensory Profile-NL. The effect size of the difference in sensory modulation patterns of children with and without SLI on this measure was large (Cohen's d ≥ 0.80). Difficulties in sensory modulation can be characterized as frequent co-morbid problems in children with SLI.

Auditory processing and speech perception in children with specific language impairment: relations with oral language and literacy skills

This longitudinal study investigated temporal auditory processing (frequency modulation and between-channel gap detection) and speech perception (speech-in-noise and categorical perception) in three groups of 6 years 3 months to 6 years 8 months-old children attending grade 1: (1) children with specific language impairment (SLI) and literacy delay (n = 8), (2) children with SLI and normal literacy (n = 10) and (3) typically developing children (n = 14). Moreover, the relations between these auditory processing and speech perception skills and oral language and literacy skills in grade 1 and grade 3 were analyzed. The SLI group with literacy delay scored significantly lower than both other groups on speech perception, but not on temporal auditory processing. Both normal reading groups did not differ in terms of speech perception or auditory processing. Speech perception was significantly related to reading and spelling in grades 1 and 3 and had a unique predictive contribution to reading growth in grade 3, even after controlling reading level, phonological ability, auditory processing and oral language skills in grade 1. These findings indicated that speech perception also had a unique direct impact upon reading development and not only through its relation with phonological awareness. Moreover, speech perception seemed to be more associated with the development of literacy skills and less with oral language ability.

Evaluating the GAPS test as a screener for language impairment in young children

BACKGROUND

The early identification of children is one of five themes identified by the Bercow review of 2008. The review also notes that there is a wide range in the methods used to identify children and it goes on to recommend that there needs to be a more systematic approach. One such approach would be to screen children before, or shortly after, school entry. The GAPS test has been designed as a screening tool to identify young children with language impairment and is reported to be of value in identifying children with language difficulties. However, the test has previously only been evaluated by its authors and the sensitivity of the test for identifying children from an unselected sample has not been evaluated.

AIMS

This study evaluated the ability of the GAPS test to identify language-impaired children in an unselected sample. In addition, the effect of tester status (a trained researcher and a teaching assistant) was investigated.

METHODS & PROCEDURES

A total of 106 children aged 3-6 years completed the GAPS test, the Early Repetition Battery (ERB) and the core language scales from the Clinical Evaluation of Language Fundamentals-Preschool 2 with a trained researcher. Half the children completed the GAPS test a second time with a teaching assistant.

OUTCOMES & RESULTS

There was a significant effect of tester only for the non-word repetition subtest of the GAPS test in the nursery age group; the teaching assistants awarded higher scores than trained researchers. Of the 106 children, ten were language impaired according to the CELF-Preschool 2 core language score. The GAPS test identified two of these children at the 10th percentile cut-off, resulting in a low sensitivity estimate of 20%. However, the GAPS test only identified four of the 96 remaining unimpaired children resulting in a high specificity value of 96%. These values were similar when the 15th percentile cut-off was used and when parental concern or a family history of reading difficulties were used as the criterion measure.

CONCLUSIONS & IMPLICATIONS

These data show that although the GAPS test can be used by a range of people who work with young children, it is not a sensitive screener for language impairment when used by trained researchers.

Reduced sensitivity to slow-rate dynamic auditory information in children with dyslexia

The etiology of developmental dyslexia remains widely debated. An appealing theory postulates that the reading and spelling problems in individuals with dyslexia originate from reduced sensitivity to slow-rate dynamic auditory cues. This low-level auditory deficit is thought to provoke a cascade of effects, including inaccurate speech perception and eventually unspecified phoneme representations. The present study investigated sensitivity to frequency modulation and amplitude rise time, speech-in-noise perception and phonological awareness in 11-year-old children with dyslexia and a matched normal-reading control children. Group comparisons demonstrated that children with dyslexia were less sensitive than normal-reading children to slow-rate dynamic auditory processing, speech-in-noise perception, phonological awareness and literacy abilities. Correlations were found between slow-rate dynamic auditory processing and phonological awareness, and speech-in-noise perception and reading. Yet, no significant correlation between slow-rate dynamic auditory processing and speech-in-noise perception was obtained. Together, these results indicate that children with dyslexia have difficulties with slow-rate dynamic auditory processing and speech-in-noise perception and that these problems persist until sixth grade.

Preschool impairments in auditory processing and speech perception uniquely predict future reading problems

Developmental dyslexia is characterized by severe reading and spelling difficulties that are persistent and resistant to the usual didactic measures and remedial efforts. It is well established that a major cause of these problems lies in poorly specified phonological representations. Many individuals with dyslexia also present impairments in auditory temporal processing and speech perception, but it remains debated whether these more basic perceptual impairments play a role in causing the reading problem. Longitudinal studies may help clarifying this issue by assessing preschool children before they receive reading instruction and by following them up through literacy development. The current longitudinal study shows impairments in auditory frequency modulation (FM) detection, speech perception and phonological awareness in kindergarten and in grade 1 in children who receive a dyslexia diagnosis in grade 3. FM sensitivity and speech-in-noise perception in kindergarten uniquely contribute to growth in reading ability, even after controlling for letter knowledge and phonological awareness. These findings indicate that impairments in auditory processing and speech perception are not merely an epiphenomenon of reading failure. Although no specific directional relations were observed between auditory processing, speech perception and phonological awareness, the highly significant concurrent and predictive correlations between all these variables suggest a reciprocal association and corroborate the evidence for the auditory deficit theory of dyslexia.

Maturation of auditory evoked potentials from 6 to 48 months: prediction to 3 and 4 year language and cognitive abilities

OBJECTIVE

To investigate the maturation of long-latency auditory evoked potentials (LLAEP) from 6 to 48 months in infants with a family history of language impairment (FH+) and control infants (FH-).

METHODS

LLAEPs of seventeen FH+ infants were compared to 28 FH- infants at 6, 9, 12, 16, 24, 36 and 48 months. Participants received a passive oddball paradigm using fast- and slow-rate non-linguistic auditory stimuli and at 36 and 48 months completed a battery of standardized language and cognitive tests.

RESULTS

Overall, the morphology of LLAEP responses differed for fast- versus slow-rate stimuli. Significant age-related changes in latency and amplitude were observed. Group differences, favoring FH- infants, in the rate of maturation of LLAEPs were found. Responses to fast-rate stimuli predicted language abilities at 36 and 48 months of age.

CONCLUSIONS

The development of LLAEP in FH+ children is modulated by differences in the rate of maturation as well as variations in temporal processing abilities.

SIGNIFICANCE

These findings provide evidence for the role of non-linguistic auditory processes in early language development and illustrate the utility of using a perceptual-processing skills model to further our understanding of the precursors of language development and impairment.

Neurokognitive Korrelate der Dyslexie

Die Überblicksarbeit widmet sich kognitiven und neuronalen Grundlagen der Dyslexie. Ausgehend von einer Darstellung der wichtigsten kognitiven und neurobiologischen Theorien der Entstehung von Dyslexie werden Ergebnisse zu spezifischen Störungen des neuronalen Lesenetzwerks bei Menschen mit Dyslexie aus Postmortem-Untersuchungen und strukturellen sowie funktionellen Bildgebungsstudien berichtet. Die Befunde legen nahe, dass Dyslexie ein multidimensionales Problem darstellt, das mit verschiedenen kognitiven, sensorischen und motorischen Defiziten und spezifischen Störungen auf neuronaler Ebene einhergeht. Zukünftige Forschung sollte sich daher verstärkt individuellen Profilen der Störung auf kognitiver wie neuronaler Ebene widmen.

Reading fluency and speech perception speed of beginning readers with persistent reading problems: the perception of initial stop consonants and consonant clusters

This study investigated the role of speech perception accuracy and speed in fluent word decoding of reading disabled (RD) children. A same-different phoneme discrimination task with natural speech tested the perception of single consonants and consonant clusters by young but persistent RD children. RD children were slower than chronological age (CA) controls in recognizing identical sounds, suggesting less distinct phonemic categories. In addition, after controlling for phonetic similarity Tallal's (Brain Lang 9:182-198, 1980) fast transitions account of RD children's speech perception problems was contrasted with Studdert-Kennedy's (Read Writ Interdiscip J 15:5-14, 2002) similarity explanation. Results showed no specific RD deficit in perceiving fast transitions. Both phonetic similarity and fast transitions influenced accurate speech perception for RD children as well as CA controls.