Auditory Processing Problems Research Articles

Brain damage related vision loss

Twenty percent of visual impairment in children is caused by brain damage. Children with brain damage related visual impairment (CVI) should be assessed in infancy and during their preschool and school age for detection of deviations from normal development of cognitive visual functions at the times these functions should normally emerge. During the last 20 years, treatment of ophthalmologic diseases has advanced greatly. A similar development has occurred in the knowledge of functioning of visually impaired children and assessment of impaired vision. However, early intervention and assessment for special education for children with CVI have not been taught by the leading teaching centres and thus paediatric vision (re)habilitation is lacking behind other areas of ophthalmology and optometry. The groups of children with motor problems, auditory processing problems, intellectual deficiencies of varying severity, who are at high risk of having CVI, are well-known but routine assessment of vision of these children is not a part of vision screening. With some further education of all paediatric services, a change in attitudes toward CVI and minor changes in routine vision services this poorly served fifth of visually impaired children could get adequate treatment, early intervention and rehabilitation.

What is the Role of Audition in Literacy?

What is the Role of Audition in Literacy?

Auditory Processing Measures: Correlation with Neuropsychological Measures of Attention, Memory, and Behavior

It has been suggested that measures of auditory processing (AP) are sensitive measures of attention resulting in the high comorbidity of auditory processing disorder (APD) and attention deficit/hyperactivity disorder (ADHD). Others have found that selected AP measures share significant variance with memory tasks. The current study investigated the relation between AP measures and various neuropsychological measures presumed to measure attention and memory in 36 children with a mean age of 7.78 years (SD = 1.61) referred to an outpatient facility. Results indicate that AP measures significantly correlated with each other as well as with some measures of attention, memory, and behavior ratings. Results suggest that although AP measures include elements of both attention and memory, these measures also appear to assess processes not tapped by other measures of attention and memory. The correlation of AP measures with parent-and teacher-rated withdrawal, parent-rated somatization, conduct, and depression, as well as teacher-rated attention, anxiety, learning problems, social skills, and leadership suggest that auditory processing problems may manifest in myriad behaviors across settings. Implications for practice and future research are presented.

Hearing loss and aging: New research findings and clinical implications

This review provides an overview of recent research that addressed hearing loss and auditory processing problems among elderly people. It focuses on research from the University of Maryland on problems in auditory temporal processing by elderly listeners as assessed in speech perception experiments using temporally altered signals and in psycho-acoustic experiments of duration and rhythm discrimination for simple and complex signals. Some recent studies of perceived hearing disability are also reviewed. The clinical implications of the research findings are discussed in relation to hearing aid performance and use by elderly people as well as potential signal processing strategies that may prove to be beneficial for this population.

The Effect of Linguistic Background on the Macquarie Pediatric Speech Intelligibility Test

Previous studies on the effect of linguistic background on tests of central auditory processing that utilise word stimuli have shown that the performance of children for whom English is a second language (ESL) is reduced compared to native English-speaking controls. Therefore, for this population, a poor score on central tests may not be an indication of an auditory processing problem, but rather the consequence of linguistic experience. In view of the potential dangers of misdiagnosis inherent in administering central auditory tests to children with ESL highlighted by these studies, a small preliminary exploration was conducted to examine the effect of ESL on the recently developed Macquarie Pediatric Speech Intelligibility Test (MPSI; Cameron, Barker, and Newall, 2003). A trend emerged whereby having English as a second language affected performance on the dichotic condition of the test at the least favourable message to competition ratio (MCR), with ESL children performing at levels usually associated with auditory processing disorder (APD). This trend highlights the need for a larger study to determine the differences in performance on the MPSI between ESL listeners and normative data collected from native English-speaking controls. Possible reasons for the results of the preliminary exploration are discussed in relation to previous research.

Theories of developmental dyslexia: insights from a multiple case study of dyslexic adults.

A multiple case study was conducted in order to assess three leading theories of developmental dyslexia: (i) the phonological theory, (ii) the magnocellular (auditory and visual) theory and (iii) the cerebellar theory. Sixteen dyslexic and 16 control university students were administered a full battery of psychometric, phonological, auditory, visual and cerebellar tests. Individual data reveal that all 16 dyslexics suffer from a phonological deficit, 10 from an auditory deficit, four from a motor deficit and two from a visual magnocellular deficit. Results suggest that a phonological deficit can appear in the absence of any other sensory or motor disorder, and is sufficient to cause a literacy impairment, as demonstrated by five of the dyslexics. Auditory disorders, when present, aggravate the phonological deficit, hence the literacy impairment. However, auditory deficits cannot be characterized simply as rapid auditory processing problems, as would be predicted by the magnocellular theory. Nor are they restricted to speech. Contrary to the cerebellar theory, we find little support for the notion that motor impairments, when found, have a cerebellar origin or reflect an automaticity deficit. Overall, the present data support the phonological theory of dyslexia, while acknowledging the presence of additional sensory and motor disorders in certain individuals.

Cognitive aging and auditory information processing

Over the last decade, much research has been conducted to investigate why older listeners report more difficulty in understanding spoken language than would be expected given their degree of audiometric hearing loss. Of particular relevance to audiological rehabilitation is recent research on older listeners when they are engaged in complex tasks involving the auditory processing of naturalistic signals in realistic social and physical environments. Discourse epitomizes such activity. By understanding age-related and individual differences in perceptual and cognitive performance, we gain important insights into how hearing impairments influence activity and participation in context. In this paper, the problems of older adults as communicators in everyday life are illuminated by studies showing that auditory processing problems affect cognitive processing, Age-related problems in understanding spoken language arc exacerbated by perceptual stressors such as noise and by cognitive stressors such as memory load. It is argued that the significance of these processing problems during discourse depends on social-emotional factors, Therefore, goals for new signal-processing technologies designed for older adults who are hard of hearing can be framed not only in terms of improving signal audibility but also in terms of reducing stress on the listener during information processing. Furthermore, goals for therapeutic interventions can be framed in terms of reducing stress during information processing by modifying behaviors and physical and social environments to achieve the listener's goals.

The role of genes in the etiology of specific language impairment

Although specific language impairment (SLI) often runs in families, most pedigrees are not consistent with a single defective gene. Before progress can be made in molecular genetics, we need a better understanding of which aspects of SLI are heritable. Twin studies are useful in allowing us to distinguish genetic from environmental influences. This point is illustrated with a study in which twins were given tests of nonword repetition (regarded as an index of phonological short-term memory) and auditory processing. Children with SLI were impaired on both measures, but these deficits had different origins. Auditory processing problems showed no evidence of genetic influence, whereas the nonword repetition deficit was highly heritable. Future genetic studies of SLI may be most effective if they use measures of underlying cognitive processes, rather than relying on conventional psychometric definitions of disorder. Learning outcomes Information in this manuscript will serve to (1) equip readers with an elementary understanding of methods used in molecular genetic studies of language impairment; (2) familiarise readers with the logic of twin studies in behavioural genetics, using both categorical and quantitative methods; (3) illustrate the importance of phenotype definition for genetic research, and the usefulness of genetic methods in illuminating theoretical relationships between deficits associated with SLI; (4) show how genetically informative methods can be used to study environmental as well as genetic influences on impairment.

Reversal of Hemispheric Asymmetry on Auditory Tasks in Children Who Are Poor Listeners

We examined hemispheric activation patterns during auditory and visual processing in two groups of children: 13 boys in the age range from 9 to 12 years rated by their parents and teachers as poor listeners and 11 boys in the same age range rated as normal listeners. Three tasks were employed: auditory gap detection, detection of auditory movement, and a control task involving visuospatial discrimination. Electrical activity was recorded from 30 scalp electrodes as participants responded to target stimuli in an event-related potential paradigm. In the visual task, hemispheric activation was relatively symmetric around the midsagittal plane in both groups. In the two auditory tasks, however, hemispheric activation patterns differed significantly between groups. In the normal-listener group, activation was asymmetric to the right hemisphere. In the poor-listener group, however, activation tended toward asymmetry, favoring the left hemisphere. These results suggest that abnormalities in hemispheric lateralization of function may underlie the auditory processing problems of at least some children described as poor listeners.

Bilirubin and the auditory system.

The auditory system is highly sensitive to bilirubin toxicity. Damage to the auditory nervous system includes auditory neuropathy or auditory dyssynchrony and auditory processing problems which may occur with or without deafness, hearing loss. Auditory dysfunction may occur in children with or without other signs of classical kernicterus. Bilirubin selectively damages the brainstem auditory nuclei, and may also damage the auditory nerve and spiral ganglion containing cell bodies of primary auditory neurons. The inner ear, thalamic and cortical auditory pathways appear to be spared. Noninvasive auditory neurophysiological tests such as the auditory brainstem response (ABR) or brainstem auditory response (BAER) play an important role in the early detection of bilirubin-induced auditory and central nervous system dysfunction in the neonate.

Auditory function at 14 years of age of very-low-birthweight children

The aim of the study was to determine audiological function at 14 years of age of very-low-birthweight (VLBW 1500g) children compared with a cohort of normal birthweight (NBW >2499g) children. Participants were consecutive surviving preterm children of birthweight <1000 g born between 1977 and 1982 (n=86) and of birthweight 1000 to 1500g born between 1980 and 1982 (n=124) and randomly selected NBW children born between 1981 and 1982 (n=60). Audiometric tests included pure tone audiometry, tympanometry, stapedius muscle reflexes, and measures of central auditory processing. Psychometric tests included measures of IQ, academic achievement, and behaviour. There were no significant differences in rates of hearing impairment, abnormal tympanograms, figure-ground problems, or digit recall between VLBW children and NBW control children. VLBW children had higher rates of some central auditory processing problems, which in turn were associated with poorer intellectual, academic, and behavioural progress.

Auditory function at 14 years of age of very‐low‐birthweight children

The aim of the study was to determine audiological function at 14 years of age of very-low-birthweight (VLBW < or = 1500 g) children compared with a cohort of normal birthweight (NBW > 2499 g) children. Participants were consecutive surviving preterm children of birthweight < 1000 g born between 1977 and 1982 (n=86) and of birthweight 1000 to 1500 g born between 1980 and 1982 (n=124) and randomly selected NBW children born between 1981 and 1982 (n=60). Audiometric tests included pure tone audiometry, tympanometry, stapedius muscle reflexes, and measures of central auditory processing. Psychometric tests included measures of IQ, academic achievement, and behaviour. There were no significant differences in rates of hearing impairment, abnormal tympanograms, figure-ground problems, or digit recall between VLBW children and NBW control children. VLBW children had higher rates of some central auditory processing problems, which in turn were associated with poorer intellectual, academic, and behavioural progress.

Ruby Tuesday

Ruby was 15, and a student at a mixed day special school for students with learning and behavioural difficulties. She was diagnosed with ADHD and had a wide range of additional learning difficulties, including auditory processing problems and literacy difficulties. These combined with classic symptoms of ADHD, including organizational problems, task avoidance and procrastination, made life very difficult for Ruby and her teachers. She would forget to bring in homework assignments and sports kit regularly despite repeated warnings, punishments and various reinforcement mechanisms.

Brain correlates of stuttering and syllable production. A PET performance-correlation analysis.

To distinguish the neural systems of normal speech from those of stuttering, PET images of brain blood flow were probed (correlated voxel-wise) with per-trial speech-behaviour scores obtained during PET imaging. Two cohorts were studied: 10 right-handed men who stuttered and 10 right-handed, age- and sex-matched non-stuttering controls. Ninety PET blood flow images were obtained in each cohort (nine per subject as three trials of each of three conditions) from which r-value statistical parametric images (SPI¿r¿) were computed. Brain correlates of stutter rate and syllable rate showed striking differences in both laterality and sign (i.e. positive or negative correlations). Stutter-rate correlates, both positive and negative, were strongly lateralized to the right cerebral and left cerebellar hemispheres. Syllable correlates in both cohorts were bilateral, with a bias towards the left cerebral and right cerebellar hemispheres, in keeping with the left-cerebral dominance for language and motor skills typical of right-handed subjects. For both stutters and syllables, the brain regions that were correlated positively were those of speech production: the mouth representation in the primary motor cortex; the supplementary motor area; the inferior lateral premotor cortex (Broca's area); the anterior insula; and the cerebellum. The principal difference between syllable-rate and stutter-rate positive correlates was hemispheric laterality. A notable exception to this rule was that cerebellar positive correlates for syllable rate were far more extensive in the stuttering cohort than in the control cohort, which suggests a specific role for the cerebellum in enabling fluent utterances in persons who stutter. Stutters were negatively correlated with right-cerebral regions (superior and middle temporal gyrus) associated with auditory perception and processing, regions which were positively correlated with syllables in both the stuttering and control cohorts. These findings support long-held theories that the brain correlates of stuttering are the speech-motor regions of the non-dominant (right) cerebral hemisphere, and extend this theory to include the non-dominant (left) cerebellar hemisphere. The present findings also indicate a specific role of the cerebellum in the fluent utterances of persons who stutter. Support is also offered for theories that implicate auditory processing problems in stuttering.

Application of a central auditory test battery in normal hearing adults with auditory problems

Objective. To study the validity of a recently developed test battery for normal hearing adults with central auditory processing problems. Materials and methods. The test battery comprised a questionnaire 1 and seven central auditory tests. 2 This test battery was administered in 10 normal hearing adults who visited our clinic because of speech perception problems. Results. The test scores of the subjects was compared with those of a reference group (n = 28). On average, test scores were significantly lower for the speech-in-noise test, filtered speech test and backward masking test. In addition, individual scores were examined, based on percentile scores. A significant relationship was found between the subjects complaints (as quantified by the questionnaire) and test scores. Conclusion. First results suggest that the test battery is valid.

Brain correlates of stuttering and syllable production: a PET performance-correlation analysis

To distinguish the neural systems of normal speech from those of stuttering, PET images of brain blood flow were probed (correlated voxel-wise) with per-trial speech-behaviour scores obtained during PET imaging. Two cohorts were studied: 10 right-handed men who stuttered and 10 right-handed, age- and sex-matched non-stuttering controls. Ninety PET blood flow images were obtained in each cohort (nine per subject as three trials of each of three conditions) from which r-value statistical parametric images (SPI?r?) were computed. Brain correlates of stutter rate and syllable rate showed striking differences in both laterality and sign (i.e. positive or negative correlations). Stutter-rate correlates, both positive and negative, were strongly lateralized to the right cerebral and left cerebellar hemispheres. Syllable correlates in both cohorts were bilateral, with a bias towards the left cerebral and right cerebellar hemispheres, in keeping with the left-cerebral dominance for language and motor skills typical of right-handed subjects. For both stutters and syllables, the brain regions that were correlated positively were those of speech production: the mouth representation in the primary motor cortex; the supplementary motor area; the inferior lateral premotor cortex (Broca's area); the anterior insula; and the cerebellum. The principal difference between syllable-rate and stutter-rate positive correlates was hemispheric laterality. A notable exception to this rule was that cerebellar positive correlates for syllable rate were far more extensive in the stuttering cohort than in the control cohort, which suggests a specific role for the cerebellum in enabling fluent utterances in persons who stutter. Stutters were negatively correlated with right-cerebral regions (superior and middle temporal gyrus) associated with auditory perception and processing, regions which were positively correlated with syllables in both the stuttering and control cohorts. These findings support long-held theories that the brain correlates of stuttering are the speech-motor regions of the non-dominant (right) cerebral hemisphere, and extend this theory to include the non-dominant (left) cerebellar hemisphere. The present findings also indicate a specific role of the cerebellum in the fluent utterances of persons who stutter. Support is also offered for theories that implicate auditory processing problems in stuttering.

Clinical Decision-Making in the Assessment and Intervention of Central Auditory Processing Disorders.

Central auditory processing disorders (CAPDs) are fraught with problems arising from confusion concerning the clinical evidence of the disorder. A major controversy revolves around characterizing the disorder as a unique cluster of behaviors reflecting impairment in some underlying mechanism(s) or as a disorder defined on the basis of performance on a set of tests. This article reviews some recent developments in auditory processing research and considers the role of the speech-language pathologist in evaluating and treating children with suspected auditory processing problems. Particular attention is given to clinical criteria, including characteristics of the population, assessment, and intervention considerations. Areas for clinical caution are highlighted.

Clinical Issues in Central Auditory Processing Disorders.

Speech-language pathologists are often faced with the need to assess and treat the suspected auditory processing problems of children with language and learning difficulties. This article discusses central auditory processing disorders (CAPDs). Included are a discussion of background information, a current definition of CAPDs, a general discussion of test battery approaches following suggestions made by the American Speech-Language- Hearing Association (ASHA) Task Force on Central Auditory Processing Consensus Development (1996), and various approaches to intervention with persons identified as having a CAPD. Finally, there is brief discussion of remaining questions to be answered. The article attempts to examine various controversies related to all aspects of CAPDs and increase the reader's awareness of current issues concerning this disorder.

Multidimensional Approach to the Differential Diagnosis of Central Auditory Processing Disorders in Children

Central auditory processing disorder (CAPD) may be viewed as a multidimensional entity with far-reaching communicative, educational, and psychosocial implications for which differential diagnosis not only is possible but also is essential to an understanding of its impact and to the development of efficacious, deficit-specific management plans. This paper begins with a description of some behavioral central auditory assessment tools in current clinical use. Four case studies illustrate the utility of these tools in clarifying the nature of auditory difficulties. Appropriate treatment options that flow logically from the diagnoses are given in each case. The heterogeneity of the population presenting with auditory processing problems, not unexpected based on this model, is made clear, as is the clinical utility of central auditory tests in the transdisciplinary assessment and management of children's language and learning difficulties.

Different origin of auditory and phonological processing problems in children with language impairment: evidence from a twin study.

This study investigated the heritability of auditory processing impairment, as assessed by Tallal's Auditory Repetition Test (ART). The sample consisted of 37 same-sex twin pairs who had previously been selected because one or both twins met criteria for language impairment (LI) and 104 same-sex twin pairs in the same age range (7 to 13 years) from the general population. These samples yielded 55 children who met criteria for LI, who were compared with 76 children whose language was normal for their age (LN group). We replicated earlier work showing that group LI is impaired relative to group LN on ART. However, there was no evidence of a heritable influence on ART scores: Correlations between twins and their co-twins were reasonably high for both MZ and DZ twins, suggesting that performance is more influenced by shared environment than genetic factors. Analyses of extreme scores gave a similar picture of nonsignificant group heritability. In contrast, a test of phonological short-term memory, the Children's Nonword Repetition Test (CNRep), gave high estimates of group heritability. In general, CNRep was a better predictor of low language test scores than ART, but ART did make a significant independent contribution in accounting for variance in a test of grammatical understanding.