The importance of modality specificity in diagnosing central auditory processing disorder

Exploring the Differences Between an Immature and a Mature Human Auditory System Through Auditory Late Responses in Quiet and in Noise

Children are disadvantaged compared to adults when they perceive speech in a noisy environment. Noise reduces their ability to extract and understand auditory information. Auditory-Evoked Late Responses (ALRs) offer insight into how the auditory system can process information in noise. This study investigated how noise, signal-to-noise ratio (SNR), and stimulus type affect ALRs in children and adults. Fifteen participants from each group with normal hearing were studied under various conditions. The findings revealed that both groups experienced delayed latencies and reduced amplitudes in noise but that children had fewer identifiable waves than adults. Babble noise had a significant impact on both groups, limiting the analysis to one condition: the /da/ stimulus at +10 dB SNR for the P1 wave. P1 amplitude was greater in quiet for children compared to adults, with no stimulus effect. Children generally exhibited longer latencies. N1 latency was longer in noise, with larger amplitudes in white noise compared to quiet for both groups. P2 latency was shorter with the verbal stimulus in quiet, with larger amplitudes in children than adults. N2 latency was shorter in quiet, with no amplitude differences between the groups. Overall, noise prolonged latencies and reduced amplitudes. Different noise types had varying impacts, with the eight-talker babble noise causing more disruption. Children's auditory system responded similarly to adults but may be more susceptible to noise. This research emphasizes the need to understand noise's impact on children's auditory development, given their exposure to noisy environments, requiring further exploration of noise parameters in children.

Impact of Otitis Media With Effusion in Early Age on Auditory Processing Abilities in Children: A Systematic Review and Meta-Analysis

Objective: Early-onset otitis media with effusion (OME) can affect the development of the auditory nervous system and thus lead to auditory processing abnormalities. This study aims to review the effect of childhood OME on auditory processing abilities in children. Methods: A systematic review of the literature, restricted to the English language from 1990 to 2022 was conducted using search engines like PubMed, Embase, and Google Scholar. After selecting the articles following predefined inclusion and exclusion criteria, the data were extracted and meta-analysis was performed. Results: A total of 10 articles met the inclusion criteria. Children with a history of OME had poorer performance in most behavioral and electrophysiological tests. Pooled analysis of various tests such as the gap in noise test, frequency pattern test (verbal and nonverbal), and latencies of auditory brainstem response-I, V, I to III, and I to V showed a difference between the 2 groups. Conclusion: Childhood OME can significantly affect auditory processing abilities in children.

Auditory Processing Disorder: Protocols and Controversy

PURPOSE

This study examined current auditory processing disorder (APD) protocols and audiologists' perspectives on the active debate seen in the literature regarding the status of APD as a unique disorder.

METHOD

This study used a cross-sectional, nonexperimental survey design. The participants were 134 U.S. audiologists, representing diversity across experience level and work setting.

RESULTS

Popular APD tests from prior surveys remain popular, and a few new tests have emerged. Most audiologists use diverse strategies to identify potential comorbid disorders as part of their APD protocol, including multidisciplinary assessment and referral to other specialists. Most participants disagreed with the assertion that APD is not a unique disorder; however, many also pointed out that patients' struggles with listening need to be the primary focus of APD assessment and management, regardless of the label of the disorder. Qualitative analysis of participant comments on the controversy yielded six themes: Clinical Experience, Comorbidity, Listening Skills, Literature Support, Overdiagnosis, and More Information Needed.

CONCLUSION

Most participants consider APD to be a unique disorder, citing clinical experience and the literature for support; however, many also indicated APD is complicated by comorbidity and APD may be overdiagnosed.

Functional Hearing Difficulties in Veterans: Retrospective Chart Review of Auditory Processing Assessments in the VA Health Care System

PURPOSE

Approximately 23 million Americans might have functional hearing difficulties (FHDs) that are not well explained by their audiometric thresholds. Clinical management of patients with FHDs is the subject of considerable debate, with few evidence-based guidelines to direct patient care. A better understanding of the characteristics of patients who seek help for FHDs, as well as current audiological management practices, is needed to direct research efforts to the areas greatest opportunity for advancement of clinical care.

METHOD

A retrospective chart review was conducted examining the medical records of a random sample of 100 Veterans who underwent auditory processing assessments across the VA Health Care System between 2008 and 2020.

RESULTS

Patients were young to middle-age, often with previous traumatic brain injury or blast exposure. Mental health, sleep, and pain disorders were common. No consistent relationships emerged between specific patient factors and domains of auditory processing deficits. Low-gain hearing aids were provided to 35 patients, 69% of whom continued wearing their hearing aids for at least 2 years.

CONCLUSION

Future research should address the potential overlap in symptoms and treatment for comorbid health conditions and FHDs, as well as the conditions underlying successful hearing aid use in this patient population.

Lack of a coherent theory limits the diagnostic and prognostic value of the (central) auditory processing disorder: a theoretical and clinical perspective

PURPOSE OF REVIEW

To consider pertinent issues towards developing a coherent theory of the auditory processing disorder (APD). By identifying the conceptual and methodological shortcomings that have thwarted development in this area for decades, we propose solutions to achieve a veridical endpoint to advance the field.

RECENT FINDINGS

Concerted efforts in the theoretical, experimental, and clinical domains have focused on validating the APD by demonstrating the " modality specificity " of the deficit. The importance of this conceptual framework is the delineation of auditory-perceptual dysfunctions from more generalized " supra modal" deficits, like those related to attention, memory, and language. Because contemporary schemata have limited the assessment of APD to auditory tasks alone ( unimodal testing), functional dissociations cannot be established, indeterminate diagnoses are problematic, and progress remains unduly constrained. The use of matched tasks in multiple sensory modalities is advocated as a diagnostic imperative to remedy this deficiency.

SUMMARY

Themes covered by this review include the need to develop a coherent theory of APD, to identify and limit factors which confound a valid diagnosis, and to validate the diagnosis by demonstrating the " modality specificity " of the deficit. Without an obligatory theoretical designation, the APD will remain as an obscure and controversial entity, limited to indeterminate test results and misdiagnoses.

Central Auditory Processing and Cognitive Functions in Children

Introduction  Nowadays, there is no consensus on whether central auditory processing disorder is a primary or a secondary deficit to other cognitive deficits. A better understanding of the association between cognitive functions and central auditory skills may help elucidate this dilemma. Objective  To investigate possible associations between auditory abilities and cognitive functions in schoolchildren. Methods  Fifty-eight schoolchildren, aged between 8 years and 0 months old and 11 years and 11 months old, who underwent the following tests: masking level difference, gaps in noise, pitch pattern sequence test, dichotic digits test, sustained auditory attention ability test, Wechsler intelligence scale for children - IV, junior Hayling test, five digits test, and behavior rating inventory of executive function. Results  Significant correlations were found between the hearing ability of temporal resolution and executive functions, temporal ordering/sequencing, binaural integration and separation, and sustained auditory attention, operational memory, inhibitory control, and cognitive flexibility; binaural integration was also associated with intelligence. The statistically significant positive correlation found between the ability of binaural interaction and the components of emotional control and behavior regulation of the behavior rating inventory of executive function was unexpected. Conclusion  The associations identified reinforce the complexity of the tasks involved in the evaluation of central auditory processing and the need for multidisciplinary evaluation for the differential diagnosis of auditory processing disorder. Confirmation of the presence or absence of comorbidities between different disorders allows directing the therapeutic behaviors and reducing the impact of possible auditory and/or cognitive deficits in the different daily life situations of children.

Relation between auditory memory and global memory in young and older adults

PURPOSE

Controversy exists as to whether auditory memory is modality-specific or not. To determine this, the study investigated the relation between the scores obtained on an auditory memory test with that obtained on a global memory test in adults. The study also aimed to compare the scores of young and older adults on the two memory tests.

METHODS

Thirty young adults aged 18 to 30 years and 30 older adults aged 58 to 70 years, having normal hearing sensitivity, were studied. Auditory memory was evaluated using the 'Kannada auditory memory and sequencing test', while global memory was assessed using the memory domain of the 'Cognitive linguistic assessment protocol for Adults' and the 'Memory ability checklist'.

RESULTS

No significant correlation was seen between the scores obtained on the auditory memory and the global memory tests in both young adults as well as older adults. Also, the scores on the memory ability checklist did not show any correlation with either global memory scores or auditory memory scores in both participant groups. Additionally, the scores of the three memory measures were found to be significantly different from each other. The older adults obtained significantly poorer scores on all three memory tools compared to young adults.

CONCLUSION

The findings indicated that auditory memory is modality-specific and is independent of global memory. Additionally, all three measures were sensitive in detecting age-related decline in memory.

Comparison of Diagnostic Auditory Processing Test Scores Measured in Clinical and School Settings

Purpose

The study aimed to compare auditory processing and cognitive test scores measured in a clinical setting with that measured in a school setting using a repeated-measures design. This was done on typically developing children and children with auditory processing disorder (APD).

Method

Thirty-two children (16 typically developing and 16 with APD), aged 7 years, were evaluated using three diagnostic auditory processing tests and a cognitive test. The tests included the Speech Perception in Noise Test in Kannada, the Gap Detection Threshold Test, the Dichotic Consonant–Vowel Test, and the Auditory Memory and Sequencing Test in Kannada. All the children were evaluated in an audiological diagnostic setting, as well as in their school.

Results

No significant difference in scores was obtained in the two settings for all the four tests that were administered. This was seen in the typically developing children and the children with APD. Additionally, the pass/fail decision for each test did not alter in the two settings. Moderate to almost perfect agreement was seen between the tests carried out in the two settings in both groups, on a Kappa test of agreement. In both settings, the children with APD performed significantly poorer than the typically developing children on the four diagnostic tests.

Conclusions

The findings of the study indicate that the diagnostic auditory processing tests and the cognitive test can be carried out in school settings as effectively as tests carried out in an audiological diagnostic clinical setting. This will enable carrying out diagnostic tests on children in schools soon after they are referred on screening auditory processing tools, administered in the educational setting. This will prevent missing diagnosis of children who fail to report to a diagnostic audiological center for detailed auditory processing evaluation.

On differentiating auditory processing disorder (APD) from attention deficit disorder (ADD): an illustrative example using the Cattell-Horn-Carroll (CHC) model of cognitive abilities

Objective: To clarify the distinction between Auditory Processing Disorder (APD) and Attention Deficit Disorder (ADD) using the CHC Model.Design: A cross-sectional study compared responses of caregivers about their children's behaviour to identify characteristics of APD (CHC Model) and ADD (DSM-5).Study Sample: Caregivers, mostly mothers (92%), of 149 children (M 61%; F 39%) aged from 6 to 16 years, referred for "Auditory Processing Assessment" of their child, were shown an A4 card displaying the characteristics of AP from the CHC Model on one side, and of ADD from DSM-5 on the other. Both sides were untitled. For each side, caregivers were asked if the characteristics were true of their child using a Conners-type four-point scale.Results: The majority of children were rated by caregivers as displaying characteristics of ADD, rather than an APD problem. Comparing problems with AP vs. problems with ADD gave: Wilcoxon T = 9.71; z = 4.86, p < 0.001.Conclusion: The finding that most children referred for an AP Assessment showed characteristics of ADD was surprising. Given the continuing audiological controversies about the nature of AP and about differentiating AP disorders from ADD, the CHC Model offers a different and informative perspective.

Same or Different: The Overlap Between Children With Auditory Processing Disorders and Children With Other Developmental Disorders: A Systematic Review

Supplemental Digital Content is available in the text.

Objectives:

Children diagnosed with auditory processing disorders (APD) experience difficulties in auditory functioning and with memory, attention, language, and reading tasks. However, it is not clear whether the behavioral characteristics of these children are distinctive from the behavioral characteristics of children diagnosed with a different developmental disorder, such as specific language impairment (SLI), dyslexia, attention-deficit hyperactivity disorder (ADHD), learning disorder (LD), or autism spectrum disorder. This study describes the performance of children diagnosed with APD, SLI, dyslexia, ADHD, and LD to different outcome measurements. The aim of this study was to determine (1) which characteristics of APD overlap with the characteristics of children with SLI, dyslexia, ADHD, LD, or autism spectrum disorder; and (2) if there are characteristics that distinguish children diagnosed with APD from children diagnosed with other developmental disorders.

Design:

A systematic review. Six electronic databases (Pubmed, CINAHL, Eric, PsychINFO, Communication & Mass Media Complete, and EMBASE) were searched to find peer-reviewed studies from 1954 to May 2015. The authors included studies reporting behaviors and performance of children with (suspected) APD and children diagnosed with a different developmental disorder (SLI, Dyslexia, ADHD, and LD). Two researchers identified and screened the studies independently. Methodological quality of the included studies was assessed with the American Speech-Language-Hearing Association’s levels-of-evidence scheme.

Results:

In total, 13 studies of which the methodological quality was moderate were included in this systematic review. In five studies, the performance of children diagnosed with APD was compared with the performance of children diagnosed with SLI: in two with children diagnosed with dyslexia, one with children diagnosed with ADHD, and in another one with children diagnosed with LD. Ten of the studies included children who met the criteria for more than one diagnosis. In four studies, there was a comparison made between the performances of children with comorbid disorders. There were no studies found in which the performance of children diagnosed with APD was compared with the performance of children diagnosed with autism spectrum disorder. Children diagnosed with APD broadly share the same characteristics as children diagnosed with other developmental disorders, with only minor differences between them. Differences were determined with the auditory and visual Duration Pattern Test, the Children’s Auditory Processing Performance Scale questionnaire, and the subtests of the Listening in Spatialized Noise-Sentences test, in which noise is spatially separated from target sentences. However, these differences are not consistent between studies and are not found in comparison to all groups of children with other developmental disorders.

Conclusions:

Children diagnosed with APD perform equally to children diagnosed with SLI, dyslexia, ADHD, and LD on tests of intelligence, memory or attention, and language tests. Only small differences between groups were found for sensory and perceptual functioning tasks (auditory and visual). In addition, children diagnosed with dyslexia performed poorer in reading tasks compared with children diagnosed with APD. The result is possibly confounded by poor quality of the research studies and the low quality of the used outcome measures. More research with higher scientific rigor is required to better understand the differences and similarities in children with various neurodevelopmental disorders.

On the Etiology of Listening Difficulties in Noise Despite Clinically Normal Audiograms

Many people with difficulties following conversations in noisy settings have “clinically normal” audiograms, that is, tone thresholds better than 20 dB HL from 0.1 to 8 kHz. This review summarizes the possible causes of such difficulties, and examines established as well as promising new psychoacoustic and electrophysiologic approaches to differentiate between them. Deficits at the level of the auditory periphery are possible even if thresholds remain around 0 dB HL, and become probable when they reach 10 to 20 dB HL. Extending the audiogram beyond 8 kHz can identify early signs of noise-induced trauma to the vulnerable basal turn of the cochlea, and might point to “hidden” losses at lower frequencies that could compromise speech reception in noise. Listening difficulties can also be a consequence of impaired central auditory processing, resulting from lesions affecting the auditory brainstem or cortex, or from abnormal patterns of sound input during developmental sensitive periods and even in adulthood. Such auditory processing disorders should be distinguished from (cognitive) linguistic deficits, and from problems with attention or working memory that may not be specific to the auditory modality. Improved diagnosis of the causes of listening difficulties in noise should lead to better treatment outcomes, by optimizing auditory training procedures to the specific deficits of individual patients, for example.

Perspectives of Dutch health professionals regarding auditory processing disorders; a focus group study

OBJECTIVE

This study investigated the perspectives of professionals from the Dutch audiological centres on the definition and care pathways of children with suspected auditory processing disorders (susAPD).

DESIGN

focus group interviews.

STUDY SAMPLE

In total, 45 professionals from 6 disciplines, representing 22 different audiological centres and one ambulatory service, participated in five parallel focus group interviews. Participants had a variety of experience in diagnosing and advising children with suspected APD.

RESULTS

Qualitative analysis (open and thematic) identified four themes ("Definition", "Causes", "Diagnostic Procedures" and "Clinical Reasoning") expressing a variety of perspectives. Differences in perspectives were mainly affected by two debates: (1) whether or not APD exists as a pure (auditory) disorder and (2) whether or not current AP-tests are suitable in diagnosing children with listening difficulties. They also expressed a need for more guidance from the literature in their clinical decision making process.

CONCLUSIONS

Professionals from the Dutch audiological centres share a broad perspective on children with APD. The ICF framework supports this perspective, thereby diminishing the need for a clear definition. The use of AP-tests should be limited to children where broader developmental disorders are first ruled out; a possible "pure" APD could then be diagnosed in a limited number of children.

[Diagnosis of auditory processing disorders in children]

Despite normal hearing thresholds in pure tone audiometry, 0.5-1 % of children have difficulty understanding what they hear. An auditory processing disorder (APD) can be assumed, which should be clarified and treated. Based on a selective literature search in the PubMed and Scopus databases using the term "auditory processing disorder", several consensus papers are discussed. Numerous studies on APD have revealed partially contradicting results, thus fueling critical discussion regarding validity and reliability-of specific audiometric APD methods and the APD construct in particular. In order to correctly advise parents and, where necessary, treat affected children, otorhinolaryngologists, phoniatrists, and pediatric audiologists must understand the psychometric properties of applied tests and have knowledge of current discussion. Diagnosis is generally a multistep interdisciplinary process.

Use of Questionnaire-Based Measures in the Assessment of Listening Difficulties in School-Aged Children

In this study, the authors assessed the potential utility of a recently developed questionnaire (Evaluation of Children’s Listening and Processing Skills [ECLiPS]) for supporting the clinical assessment of children referred for auditory processing disorder (APD).

Questionnaires potentially offer valuable information about everyday listening difficulty in children referred for suspected APD. However, there are many problems with currently available questionnaires. This paper considers the validity and usefulness of a new questionnaire called the Evaluation of Children’s Listening and Processing Skills (ECLiPS) in comparison with three other available questionnaires. All the questionnaires in the study were similarly sensitive to the presence of problems, but the ECLiPS provided clearer evidence of construct validity particularly with respect to measures of cognitive abilities. Discriminant analysis suggested that a combination of ECLiPS factors with auditory and cognitive measures achieved best discrimination among the participant groups in the study.

Mind the Gap: Two Dissociable Mechanisms of Temporal Processing in the Auditory System

High temporal acuity of auditory processing underlies perception of speech and other rapidly varying sounds. A common measure of auditory temporal acuity in humans is the threshold for detection of brief gaps in noise. Gap-detection deficits, observed in developmental disorders, are considered evidence for "sluggish" auditory processing. Here we show, in a mouse model of gap-detection deficits, that auditory brain sensitivity to brief gaps in noise can be impaired even without a general loss of central auditory temporal acuity. Extracellular recordings in three different subdivisions of the auditory thalamus in anesthetized mice revealed a stimulus-specific, subdivision-specific deficit in thalamic sensitivity to brief gaps in noise in experimental animals relative to controls. Neural responses to brief gaps in noise were reduced, but responses to other rapidly changing stimuli unaffected, in lemniscal and nonlemniscal (but not polysensory) subdivisions of the medial geniculate body. Through experiments and modeling, we demonstrate that the observed deficits in thalamic sensitivity to brief gaps in noise arise from reduced neural population activity following noise offsets, but not onsets. These results reveal dissociable sound-onset-sensitive and sound-offset-sensitive channels underlying auditory temporal processing, and suggest that gap-detection deficits can arise from specific impairment of the sound-offset-sensitive channel.

SIGNIFICANCE STATEMENT

The experimental and modeling results reported here suggest a new hypothesis regarding the mechanisms of temporal processing in the auditory system. Using a mouse model of auditory temporal processing deficits, we demonstrate the existence of specific abnormalities in auditory thalamic activity following sound offsets, but not sound onsets. These results reveal dissociable sound-onset-sensitive and sound-offset-sensitive mechanisms underlying auditory processing of temporally varying sounds. Furthermore, the findings suggest that auditory temporal processing deficits, such as impairments in gap-in-noise detection, could arise from reduced brain sensitivity to sound offsets alone.

Characteristics of Auditory Processing Disorders: A Systematic Review

PURPOSE

The purpose of this review article is to describe characteristics of auditory processing disorders (APD) by evaluating the literature in which children with suspected or diagnosed APD were compared with typically developing children and to determine whether APD must be regarded as a deficit specific to the auditory modality or as a multimodal deficit.

METHOD

Six electronic databases were searched for peer-reviewed studies investigating children with (suspected) APD in comparison with typically developing peers. Relevant studies were independently reviewed and appraised by 2 reviewers. Methodological quality was quantified using the American Speech-Language-Hearing Association's levels of evidence.

RESULTS

Fifty-three relevant studies were identified. Five studies were excluded because of weak internal validity. In total, 48 studies were included, of which only 1 was classified as having strong methodological quality. Significant dissimilarities were found between children referred with listening difficulties and controls. These differences relate to auditory and visual functioning, cognition, language, reading, and physiological and neuroimaging measures.

CONCLUSIONS

Methodological quality of most of the incorporated studies was rated moderate due to the heterogeneous groups of participants, inadequate descriptions of participants, and the omission of valid and reliable measurements. The listening difficulties of children with APD may be a consequence of cognitive, language, and attention issues rather than bottom-up auditory processing.

Functional auditory disorders

There are a number of auditory symptom syndromes that can develop without an organic basis. Some of these, such as nonorganic hearing loss, affect populations similar to those presenting with functional somatosensory and motor symptoms, while others, such as musical hallucination, affect populations with a significantly different demographic and require different treatment strategies. Many of these conditions owe their origin to measurably abnormal peripheral sensory pathology or brain network activity, but their pathological impact is often due, at least in part, to overamplification of the salience of these phenomena. For each syndrome, this chapter briefly outlines a definition, demographics, investigations, putative mechanisms, and treatment strategies. Consideration is given to what extent they can be considered to have a functional basis. Treatments are in many cases pragmatic and rudimentary, needing more work to be done in integrating insights from behavioral and cognitive psychology to auditory neuroscience. The audiology literature has historically equated the term functional with malingering, although this perception is, thankfully, slowly changing. These disorders transcend the disciplines of audiology, otorhinolaryngology, neurology and psychiatry, and a multidisciplinary approach is often rewarding.

It Is Time to Rethink Central Auditory Processing Disorder Protocols for School-Aged Children

PURPOSE

The purpose of this article is to review the literature that pertains to ongoing concerns regarding the central auditory processing construct among school-aged children and to assess whether the degree of uncertainty surrounding central auditory processing disorder (CAPD) warrants a change in current protocols.

METHOD

Methodology on this topic included a review of relevant and recent literature through electronic search tools (e.g., ComDisDome, PsycINFO, Medline, and Cochrane databases); published texts; as well as published articles from the Journal of the American Academy of Audiology; the American Journal of Audiology; the Journal of Speech, Language, and Hearing Research; and Language, Speech, and Hearing Services in Schools.

RESULTS

This review revealed strong support for the following: (a) Current testing of CAPD is highly influenced by nonauditory factors, including memory, attention, language, and executive function; (b) the lack of agreement regarding the performance criteria for diagnosis is concerning; (c) the contribution of auditory processing abilities to language, reading, and academic and listening abilities, as assessed by current measures, is not significant; and (d) the effectiveness of auditory interventions for improving communication abilities has not been established.

CONCLUSIONS

Routine use of CAPD test protocols cannot be supported, and strong consideration should be given to redirecting focus on assessing overall listening abilities. Also, intervention needs to be contextualized and functional. A suggested protocol is provided for consideration. All of these issues warrant ongoing research.

Central auditory processing disorders in children and adults

Central auditory processing disorders (CAPD) can affect children and adults of all ages due to a wide variety of causes. CAPD is a neurobiologic deficit in the central auditory nervous system (CANS) that affects those mechanisms that underlie fundamental auditory perception, including localization and lateralization; discrimination of speech and non-speech sounds; auditory pattern recognition; temporal aspects of audition, including integration, resolution, ordering, and masking; and auditory performance with competing and/or degraded acoustic signals (American Speech-Language-Hearing Association, 2005a, b). Although it is recognized that central auditory dysfunction may coexist with other disorders, CAPD is conceptualized as a sensory-based auditory disorder. Administration of behavioral and/or electrophysiologic audiologic tests that have been shown to be sensitive and specific to dysfunction of the CANS is critical for a proper diagnosis of CAPD, in addition to assessments and collaboration with a multidisciplinary team. Intervention recommendations for CAPD diagnosis are based on the demonstrated auditory processing deficits and related listening and related complaints. This chapter provides an overview of current definitions and conceptualizations, methods of diagnosis of, and intervention for, CAPD. The chapter culminates with a case study illustrating pre- and posttreatment behavioral and electrophysiologic diagnostic findings.

Attention, memory, and auditory processing in 10- to 15-year-old children with listening difficulties

PURPOSE

The aim of this study was to examine attention, memory, and auditory processing in children with reported listening difficulty in noise (LDN) despite having clinically normal hearing.

METHOD

Twenty-one children with LDN and 15 children with no listening concerns (controls) participated. The clinically normed auditory processing tests included the Frequency/Pitch Pattern Test (FPT; Musiek, 2002), the Dichotic Digits Test (Musiek, 1983), the Listening in Spatialized Noise-Sentences (LiSN-S) test (Dillon, Cameron, Glyde, Wilson, & Tomlin, 2012), gap detection in noise (Baker, Jayewardene, Sayle, & Saeed, 2008), and masking level difference (MLD; Wilson, Moncrieff, Townsend, & Pillion, 2003). Also included were research-based psychoacoustic tasks, such as auditory stream segregation, localization, sinusoidal amplitude modulation (SAM), and fine structure perception. All were also evaluated on attention and memory test batteries.

RESULTS

The LDN group was significantly slower switching their auditory attention and had poorer inhibitory control. Additionally, the group mean results showed significantly poorer performance on FPT, MLD, 4-Hz SAM, and memory tests. Close inspection of the individual data revealed that only 5 participants (out of 21) in the LDN group showed significantly poor performance on FPT compared with clinical norms. Further testing revealed the frequency discrimination of these 5 children to be significantly impaired.

CONCLUSION

Thus, the LDN group showed deficits in attention switching and inhibitory control, whereas only a subset of these participants demonstrated an additional frequency resolution deficit.

Simulating the effects of common and specific abilities on test performance: an evaluation of factor analysis

PURPOSE

Factor analysis is a useful technique to aid in organizing multivariate data characterizing speech, language, and auditory abilities. However, knowledge of the limitations of factor analysis is essential for proper interpretation of results. The present study used simulated test scores to illustrate some characteristics of factor analysis.

METHOD

Linear models were used to simulate test scores that were determined by multiple latent variables. These simulated test scores were evaluated with principal components analysis and, in certain cases, structural equation modeling. In addition, a subset of simulated individuals characterized by poor test performance was examined.

RESULTS

The number of factors recovered and their identity do not necessarily correspond to the structure of the latent variables that generated the test scores. The first principal component may represent variance from multiple uncorrelated sources. Practices such as correction or control for general cognitive ability may produce misleading results.

CONCLUSIONS

Inferences from the results of factor analysis should be primarily about the structure of test batteries rather than the structure of human mental abilities. Researchers and clinicians should consider multiple sources of evidence to evaluate hypotheses about the processes generating test results.

Reduced resting-state brain activity in the default mode network in children with (central) auditory processing disorders

BACKGROUND

In recent years, there has been a growing interest in Central Auditory Processing Disorder (C)APD. However, the neural correlates of (C)APD are poorly understood. Previous neuroimaging experiments have shown changes in the intrinsic activity of the brain in various cognitive deficits and brain disorders. The present study investigated the spontaneous brain activity in (C)APD subjects with resting-state fMRI (rs-fMRI).

METHODS

Thirteen children diagnosed with (C)APD and fifteen age and gender-matched controls participated in a rs-fMRI study during which they were asked to relax keeping their eyes open. Two different techniques of the rs-fMRI data analysis were used: Regional Homogeneity (ReHo) and Independent Component Analysis (ICA), which approach is rare.

RESULTS

Both methods of data analysis showed comparable results in the pattern of DMN activity within groups. Additionally, ReHo analysis revealed increased co-activation of the superior frontal gyrus, the posterior cingulate cortex/the precuneus in controls, compared to the (C)APD group. ICA yielded inconsistent results across groups.

CONCLUSIONS

Our ReHo results suggest that (C)APD children seem to present reduced regional homogeneity in brain regions considered a part of the default mode network (DMN). These findings might contribute to a better understanding of neural mechanisms of (C)APD.

Altered white matter microstructure underlies listening difficulties in children suspected of auditory processing disorders: a DTI study

INTRODUCTION

The purpose of the present study was to identify biomarkers of listening difficulties by investigating white matter microstructure in children suspected of auditory processing disorder (APD) using diffusion tensor imaging (DTI). Behavioral studies have suggested that impaired cognitive and/or attention abilities rather than a pure sensory processing deficit underlie listening difficulties and auditory processing disorder (APD) in children. However, the neural signature of listening difficulties has not been investigated.

METHODS

Twelve children with listening difficulties and atypical left ear advantage (LEA) in dichotic listening and twelve age- and gender-matched typically developing children with typical right ear advantage (REA) were tested. Using voxel-based analysis, fractional anisotropy (FA), and mean, axial and radial diffusivity (MD, AD, RD) maps were computed and contrasted between the groups.

RESULTS

Listening difficulties were associated with altered white matter microstructure, reflected by decreased FA in frontal multifocal white matter regions centered in prefrontal cortex bilaterally and left anterior cingulate. Increased RD and decreased AD accounted for the decreased FA, suggesting delayed myelination in frontal white matter tracts and disrupted fiber organization in the LEA group. Furthermore, listening difficulties were associated with increased MD (with increase in both RD and AD) in the posterior limb of the internal capsule (sublenticular part) at the auditory radiations where auditory input is transmitted between the thalamus and the auditory cortex.

CONCLUSIONS

Our results provide direct evidence that listening difficulties in children are associated with altered white matter microstructure and that both sensory and supramodal deficits underlie the differences between the groups.

Assessment of auditory processing disorder in children using an adaptive filtered speech test

OBJECTIVE

One type of test commonly used to assess auditory processing disorder (APD) is the 'filtered words test' (FWT), in which a monaural, low-redundancy speech sample is distorted by using filtering to modify its frequency content. One limitation of the various existing FWTs is that they are performed using a constant level of low-pass filtering, making them prone to ceiling and floor effects that compromise their efficiency and accuracy. A recently developed computer-based test, the University of Canterbury Adaptive Speech Test- Filtered Words (UCAST-FW), uses an adaptive procedure intended to improve the efficiency and sensitivity of the test over its constant-level counterparts.

DESIGN

The UCAST-FW was administered to school-aged children to investigate the ability of the test to distinguish between children with and without APD.

STUDY SAMPLE

Fifteen children aged 7-13 diagnosed with APD, and an aged-matched control group of 10 children with no history of listening difficulties.

RESULTS

Data obtained demonstrates a significant difference between the UCAST-FW results obtained by children with APD and those with normal auditory processing.

CONCLUSIONS

These findings provide evidence that the UCAST-FW may discriminate between children with and without APD with greater sensitivity than its constant-level counterparts.

Left ear advantage in speech-related dichotic listening is not specific to auditory processing disorder in children: A machine-learning fMRI and DTI study

Dichotic listening (DL) tests are among the most frequently included in batteries for the diagnosis of auditory processing disorders (APD) in children. A finding of atypical left ear advantage (LEA) for speech-related stimuli is often taken by clinical audiologists as an indicator for APD. However, the precise etiology of ear advantage in DL tests has been a source of debate for decades. It is uncertain whether a finding of LEA is truly indicative of a sensory processing deficit such as APD, or whether attentional or other supramodal factors may also influence ear advantage. Multivariate machine learning was used on diffusion tensor imaging (DTI) and functional MRI (fMRI) data from a cohort of children ages 7–14 referred for APD testing with LEA, and typical controls with right-ear advantage (REA). LEA was predicted by: increased axial diffusivity in the left internal capsule (sublenticular region), and decreased functional activation in the left frontal eye fields (BA 8) during words presented diotically as compared to words presented dichotically, compared to children with right-ear advantage (REA). These results indicate that both sensory and attentional deficits may be predictive of LEA, and thus a finding of LEA, while possibly due to sensory factors, is not a specific indicator of APD as it may stem from a supramodal etiology.

•

Left-ear advantage (LEA) in speech-related dichotic listening tests is atypical.

•

LEA is predicted by differences in functional activation in frontal eye fields.

•

LEA also predicted by differences in WM microstructure in left auditory radiation.

•

LEA is therefore not specific for auditory processing disorder (APD) in children.

A computer-based auditory sequential pattern test for school-aged children

OBJECTIVE

One type of test commonly used to assess auditory processing disorders (APD) is the Frequency Pattern Test, in which triads of pure tones of two different frequencies are presented, and participants are required to accurately report the sequence of tones, typically using a verbal response. The test is widely used clinically, but in its current format, is an under-exploited means of addressing some candidate processes, such as temporal ordering and frequency discrimination, which might be affected in APD. Here we describe a computer-based version of an auditory pattern perception test, the BirdSong Game, which was designed to be an engaging research tool for use with school-aged children.

METHODS

In this study, 128 children aged 6-10 with normal peripheral hearing were tested. The BirdSong Game application was used to administer auditory sequential pattern tests, via a touch-screen presentation and response interface. A conditioning step was included prior to testing, in order to ensure that participants were able to adequately discriminate between the test tones, and reliably describe the difference using their own vocabulary. Responses were collected either verbally or manually, by having participants press cartoon images on the touch-screen in the appropriate sequence. The data was examined for age, gender and response mode differences.

RESULTS

Findings on the auditory tests indicated a significant maturational effect across the age range studied, with no difference between response modes or gender.

CONCLUSIONS

The BirdSong Game is sensitive to maturational changes in auditory sequencing ability, and the computer-based design of the test has several advantages which make it a potentially useful clinical and research tool.

A case study of the changes in the speech-evoked auditory brainstem response associated with auditory training in children with auditory processing disorders

BACKGROUND

Studies related to plasticity and learning-related phenomena have primarily focused on higher-order processes of the auditory system, such as those in the auditory cortex and limited information is available on learning- and plasticity-related processes in the auditory brainstem.

DESIGN AND METHOD

A clinical electrophysiological test of speech-evoked ABR known as BioMARK has been developed to evaluate brainstem responses to speech sounds in children with language learning disorders. Fast ForWord (FFW) was used as an auditory intervention program in the current study and pre- intervention and post-intervention speech-evoked ABR (BioMARK) measures were compared in 2 school-aged children with auditory processing disorders (APD).

RESULTS AND CONCLUSIONS

Significant changes were noted from pre-intervention to post-intervention and reflect plasticity in the auditory brainstem's neural activity to speech stimuli.

Using different criteria to diagnose (central) auditory processing disorder: how big a difference does it make?

PURPOSE

To quantify how 9 different diagnostic criteria affected potential (central) auditory processing disorder ([C]APD) diagnoses in a large sample of children referred for (central) auditory processing ([C]AP) assessment.

METHOD

A file review was conducted on 150 children (94 boys and 56 girls; ages 7.0-15.6 years) with normal peripheral hearing who had completed a (C)AP assessment involving low-pass filtered speech, competing sentences, 2-pair dichotic digits, and frequency patterns with linguistic and nonlinguistic report. Each child was classified as having or not having (C)APD based on 9 different sets of diagnostic criteria drawn from published technical reports, position statements, and selected research.

RESULTS

The rates of potential (C)APD diagnosis ranged from 7.3% for the strictest criteria to 96.0% for the most lenient criteria.

CONCLUSIONS

Until greater consensus is reached, any diagnosis of (C)APD should be qualified by an explicit statement of the criteria used. Calls to abandon the use of (C)APD as a global label should also be supported.

Central presbycusis: a review and evaluation of the evidence

BACKGROUND

The authors reviewed the evidence regarding the existence of age-related declines in central auditory processes and the consequences of any such declines for everyday communication.

PURPOSE

This report summarizes the review process and presents its findings.

DATA COLLECTION AND ANALYSIS

The authors reviewed 165 articles germane to central presbycusis. Of the 165 articles, 132 articles with a focus on human behavioral measures for either speech or nonspeech stimuli were selected for further analysis.

RESULTS

For 76 smaller-scale studies of speech understanding in older adults reviewed, the following findings emerged: (1) the three most commonly studied behavioral measures were speech in competition, temporally distorted speech, and binaural speech perception (especially dichotic listening); (2) for speech in competition and temporally degraded speech, hearing loss proved to have a significant negative effect on performance in most of the laboratory studies; (3) significant negative effects of age, unconfounded by hearing loss, were observed in most of the studies of speech in competing speech, time-compressed speech, and binaural speech perception; and (4) the influence of cognitive processing on speech understanding has been examined much less frequently, but when included, significant positive associations with speech understanding were observed. For 36 smaller-scale studies of the perception of nonspeech stimuli by older adults reviewed, the following findings emerged: (1) the three most frequently studied behavioral measures were gap detection, temporal discrimination, and temporal-order discrimination or identification; (2) hearing loss was seldom a significant factor; and (3) negative effects of age were almost always observed. For 18 studies reviewed that made use of test batteries and medium-to-large sample sizes, the following findings emerged: (1) all studies included speech-based measures of auditory processing; (2) 4 of the 18 studies included nonspeech stimuli; (3) for the speech-based measures, monaural speech in a competing-speech background, dichotic speech, and monaural time-compressed speech were investigated most frequently; (4) the most frequently used tests were the Synthetic Sentence Identification (SSI) test with Ipsilateral Competing Message (ICM), the Dichotic Sentence Identification (DSI) test, and time-compressed speech; (5) many of these studies using speech-based measures reported significant effects of age, but most of these studies were confounded by declines in hearing, cognition, or both; (6) for nonspeech auditory-processing measures, the focus was on measures of temporal processing in all four studies; (7) effects of cognition on nonspeech measures of auditory processing have been studied less frequently, with mixed results, whereas the effects of hearing loss on performance were minimal due to judicious selection of stimuli; and (8) there is a paucity of observational studies using test batteries and longitudinal designs.

CONCLUSIONS

Based on this review of the scientific literature, there is insufficient evidence to confirm the existence of central presbycusis as an isolated entity. On the other hand, recent evidence has been accumulating in support of the existence of central presbycusis as a multifactorial condition that involves age- and/or disease-related changes in the auditory system and in the brain. Moreover, there is a clear need for additional research in this area.

Auditory processing theories of language disorders: past, present, and future

PURPOSE

The purpose of this article is to provide information that will assist readers in understanding and interpreting research literature on the role of auditory processing in communication disorders.

METHOD

A narrative review was used to summarize and synthesize the literature on auditory processing deficits in children with auditory processing disorder (APD), specific language impairment (SLI), and dyslexia. The history of auditory processing theories of these 3 disorders is described, points of convergence and controversy within and among the different branches of research literature are considered, and the influence of research on practice is discussed. The theoretical and clinical contributions of neurophysiological methods are also reviewed, and suggested approaches for critical reading of the research literature are provided.

CONCLUSION

Research on the role of auditory processing in communication disorders springs from a variety of theoretical perspectives and assumptions, and this variety, combined with controversies over the interpretation of research results, makes it difficult to draw clinical implications from the literature. Neurophysiological research methods are a promising route to better understanding of auditory processing. Progress in theory development and its clinical application is most likely to be made when researchers from different disciplines and theoretical perspectives communicate clearly and combine the strengths of their approaches.

Diffusion tensor imaging reveals white matter microstructure correlations with auditory processing ability

OBJECTIVE

Correlation of white matter microstructure with various cognitive processing tasks and with overall intelligence has been previously demonstrated. We investigate the correlation of white matter microstructure with various higher-order auditory processing tasks, including interpretation of speech-in-noise, recognition of low-pass frequency filtered words, and interpretation of time-compressed sentences at two different values of compression. These tests are typically used to diagnose auditory processing disorder (APD) in children. Our hypothesis is that correlations between white matter microstructure in tracts connecting the temporal, frontal, and parietal lobes, as well as callosal pathways, will be seen. Previous functional imaging studies have shown correlations between activation in temporal, frontal, and parietal regions from higher-order auditory processing tasks. In addition, we hypothesize that the regions displaying correlations will vary according to the task because each task uses a different set of skills.

DESIGN

Diffusion tensor imaging (DTI) data were acquired from a cohort of 17 normal-hearing children aged 9 to 11 yrs. Fractional anisotropy (FA), a measure of white matter fiber tract integrity and organization, was computed and correlated on a voxelwise basis with performance on the auditory processing tasks, controlling for age, sex, and full-scale IQ.

RESULTS

Divergent correlations of white matter FA depending on the particular auditory processing task were found. Positive correlations were found between FA and speech-in-noise in white matter adjoining prefrontal areas and between FA and filtered words in the corpus callosum. Regions exhibiting correlations with time-compressed sentences varied depending on the degree of compression: the greater degree of compression (with the greatest difficulty) resulted in correlations in white matter adjoining prefrontal (dorsal and ventral), whereas the smaller degree of compression (with less difficulty) resulted in correlations in white matter adjoining audiovisual association areas and the posterior cingulate. Only the time-compressed sentences with the lowest degree of compression resulted in positive correlations in the centrum semiovale; all the other tasks resulted in negative correlations.

CONCLUSIONS

The dependence of performance on higher-order auditory processing tasks on brain anatomical connectivity was seen in normal-hearing children aged 9 to 11 yrs. Results support a previously hypothesized dual-stream (dorsal and ventral) model of auditory processing, and that higher-order processing tasks rely less on the dorsal stream related to articulatory networks and more on the ventral stream related to semantic comprehension. Results also show that the regions correlating with auditory processing vary according to the specific task, indicating that the neurological bases for the various tests used to diagnose APD in children may be partially independent.

Auditive Verarbeitungs- und Wahrnehmungsstörungen (AVWS) im Kindesalter

Auditive Verarbeitungs- und Wahrnehmungsstörungen (AVWS) sind umschriebene Funktionsdefizite in der auditiven Informationsverarbeitung und Wahrnehmung bei intaktem peripherem Gehör und mindestens durchschnittlicher Intelligenz. Häufig sind Lernstörungen, primäre bzw. sekundäre Spracherwerbsstörungen, supramodale Aufmerksamkeitsprobleme oder tiefgreifende Entwicklungsstörungen mit AVWS im Sinn von Komorbidität assoziiert. Deswegen erscheint Eltern, Lehrern oder Untersuchern das AVWS-Konzept zur Erklärung solcher Entwicklungs- und Lernauffälligkeiten plausibel. Da Sprachsignale zerebral anders als nicht sprachliche Signale ausgewertet werden, kann Sprachwahrnehmung allenfalls als ein Spezialfall der auditiven Verarbeitung und Wahrnehmung betrachtet werden. Kausale Beziehungen zwischen gestörten auditiven Funktionen und klinischen Störungsbildern wurden bislang nicht zuverlässig belegt. Es besteht ein Mangel an kontrollierten bzw. randomisierten Therapiestudien.

Expressive vocabulary and auditory processing in children with deviant speech acquisition

BACKGROUND

expressive vocabulary and auditory processing in children with phonological disorder.

AIM

to compare the performance of children with phonological disorder in a vocabulary test with the parameters indicated by the same test and to verify a possible relationship between this performance and auditory processing deficits.

METHOD

participants were 12 children diagnosed with phonological disorders, with ages ranging from 5 to 7 years, of both genders. Vocabulary was assessed using the ABFW language test and the simplified auditory processing evaluation (sorting), Alternate Dichotic Dissyllable - Staggered Spondaic Word (SSW), Pitch Pattern Sequence (PPS) and the Binaural Fusion Test (BF).

RESULTS

considering performance in the vocabulary test, all children obtained results with no significant statistical. As for the auditory processing assessment, all children presented better results than expected; the only exception was on the sorting process testing, where the mean accuracy score was of 8.25. Regarding the performance in the other auditory processing tests, the mean accuracy averages were 6.50 in the SSW, 10.74 in the PPS and 7.10 in the BF. When correlating the performance obtained in both assessments, considering p>0.05, the results indicated that, despite the normality, the lower the value obtained in the auditory processing assessment, the lower the accuracy presented in the vocabulary test. A trend was observed for the semantic fields of "means of transportation and professions". Considering the classification categories of the vocabulary test, the SP (substitution processes) were the categories that presented the higher significant increase in all semantic fields.

CONCLUSION

there is a correlation between the auditory processing and the lexicon, where vocabulary can be influenced in children with deviant speech acquisition.

Childhood auditory processing disorder as a developmental disorder: the case for a multi-professional approach to diagnosis and management

Auditory processing disorder (APD) is diagnosed when a patient presents with listening difficulties which can not be explained by a peripheral hearing impairment or higher-order cognitive or language problems. This review explores the association between auditory processing disorder (APD) and other specific developmental disorders such as dyslexia and attention-deficit hyperactivity disorder. The diagnosis and aetiology of APD are similar to those of other developmental disorders and it is well established that APD often co-occurs with impairments of language, literacy, and attention. The genetic and neurological causes of APD are poorly understood, but developmental and behavioural genetic research with other disorders suggests that clinicians should expect APD to co-occur with other symptoms frequently. The clinical implications of co-occurring symptoms of other developmental disorders are considered and the review concludes that a multi-professional approach to the diagnosis and management of APD, involving speech and language therapy and psychology as well as audiology, is essential to ensure that children have access to the most appropriate range of support and interventions.

Relação entre habilidades de processamento auditivo e funções neuropsicológicas em adolescentes

OBJETIVO: averiguar a existência de relações entre o desempenho em testes de processamento auditivo e em tarefas cognitivas. MÉTODOS: participaram 12 adolescentes com desenvolvimento típico, estudantes de terceiro ano do Ensino Médio de escolas privadas do estado do Rio Grande do Sul, Brasil, examinados com uma bateria de testes de PA(C) e com o Instrumento de Avaliação Neuropsicológica Breve Neupsilin. Foram realizadas análises de correlação de Pearson e análises qualitativas intertestes para comparação do desempenho na avaliação do PA(C) e na avaliação neuropsicológica. RESULTADOS: da bateria de testes PA(C), os Testes SSI - MCI - Teste de Sentenças Sintéticas com mensagem competitiva ipsilateral, SSW - Teste de Dissílabos Alternados e o teste Dicóticos de Dígitos apresentaram correlação forte significativa positiva (coeficiente de correlação de Pearson) com os subtestes do Neupsilin: atenção - contagem inversa, percepção de faces, linguagem oral automática e repetição, memória verbal episódica e memória de trabalho - span auditivo de palavras em sentenças. Alguns testes do PA(C) apresentaram maior frequência de dissociações com subtestes neuropsicológicos. As correlações encontradas indicam que os testes de PA(C) e as tarefas neuropsicológicas parecem examinar algumas habilidades cognitivas subjacentes em comum. As dissociações observadas sugerem que os processamentos auditivo e neuropsicológico são relativamente independentes e a análise intertestes do desempenho dos participantes na avaliação do PA(C), comparada ao desempenho na avaliação neuropsicológica, confirma os resultados encontrados para as questões anteriores. CONCLUSÃO: ressalta-se a necessidade de se pensar o contexto da administração dos testes de PA(C), considerando-se a relação de complementaridade da avaliação neuropsicológica e do exame de processamento auditivo.

[Sequential information processing in children with and without auditory processing disorder]

BACKGROUND

It is a controversial issue whether sequential processing in children with auditory processing disorders (APD) is a unimodal auditory impairment.

PATIENTS AND METHODS

Normal achieving controls (n=12; mean age: 101.1 months; SD 20.3) and children referred to clinical facilities for assessment including children with monosymptomatic APD (n=25; mean age: 90.8 months; SD 9.8), children with developmental language disorder (DLD]) + APD (n=11; mean age: 89.5 months; SD 14.9), children with dyslexia + APD (n=10; mean age: 113.8 months; SD 17.1) were compared using the subtest digit recall of the German version of the K-ABC (Melchers & Preuss 2001) and the K-ABC subtest hand movements in the visual modality.

RESULTS

On average all groups tended to perform alike in visual sequential processing and memory (T-score>50). Normal controls (non-APD) showed on average the best test performance (T-score 57.4; SD 10.5), but the mean performance did not differ significantly from children with APD. All groups also presented on average normal test performance in the auditory modality however, children of the clinical groups were below the age mean (DLD + APD: T-W 43.1; SD 6.8; monosymptomatic APD: T-W 45.8; SD 9.8; dyslexia + APD: 46.7; SD5.8). Children with DLD + APD and those with monosymptomatic APD exhibited a significantly lower but not poor performance in auditory processing of sequences compared to their performance in visual sequential processing. The results of auditory and visual processing of sequences were significantly correlated in the clinical groups DLD + APD (0.58) and monosymptomatic APD (0.34), but not in the smallest group dyslexia + APD (0.48) and in normal achieving controls (0.32).

CONCLUSION

On the basis of the results of the present study it may be concluded that a normal test performance on visual measure does not exclude a bimodal or pansensory seriation disorder in children with APD. It does, however, indicate the existence of a primary auditory sequential processing deficit, because at least the processing of phonological and visual stimuli was not separately carried out in children with DLD + APD.

Auditory processing disorder and speech perception problems in noise: finding the underlying origin

PURPOSE

A hallmark listening problem of individuals presenting with auditory processing disorder (APD) is their poor recognition of speech in noise. The underlying perceptual problem of the listening difficulties in unfavorable listening conditions is unknown. The objective of this article was to demonstrate theoretically how to determine whether the speech recognition problems are related to an auditory dysfunction, a language-based dysfunction, or a combination of both.

METHOD

Tests such as the Speech Perception in Noise (SPIN) test allow the exploration of the auditory and language-based functions involved in speech perception in noise, which is not possible with most other speech-in-noise tests. Psychometric functions illustrating results from hypothetical groups of individuals with APD on the SPIN test are presented. This approach makes it possible to postulate about the origin of the speech perception problems in noise.

CONCLUSION

APD is a complex and heterogeneous disorder for which the underlying deficit is currently unclear. Because of their design, SPIN-like tests can potentially be used to identify the nature of the deficits underlying problems with speech perception in noise for this population. A better understanding of the difficulties with speech perception in noise experienced by many listeners with APD should lead to more efficient intervention programs.

Influence, education, and advocacy: the pediatric nurse's role in the evaluation and management of children with central auditory processing disorders

PURPOSE

This discussion presents central auditory processing disorders to pediatric nurses who can influence decisions, educate parents and children, and advocate for children and families in the healthcare and educational settings.

CONCLUSIONS

Nurses' understanding of central auditory processing disorders and their signs and symptoms may help prevent misdiagnosis or underdiagnosis in the pediatric population.

PRACTICE IMPLICATIONS

The common indicators of central auditory processing disorders often mimic other childhood disorders such as attention deficit hyperactivity disorder. Testing for central auditory processing disorders is optimized when children are on the appropriate medication at the time of testing.

[Assessment of central auditory processes in Spanish in children with dyslexia and controls. Binaural Fusion Test and Filtered Word Test]

OBJECTIVES

The aim is to assess the ability to discriminate words, using two psychoacoustic verbal tests of central auditory processes in Spanish: Binaural Fusion Test (BFT in its Spanish version) and Filtered Word Test (FWT in its Spanish version) in children with dyslexia and controls.

METHODS

One group of 40 dyslexic children was receiving therapy for dyslexia at the time of the tests. 40 children without dyslexia were selected as controls, out of 298 children who attended a public school.

RESULTS

The rate of males to females was 2/1 in the dyslexic group. The average correct answers for the BFT were 65-66% in dyslexic group and 75-80% in the control group. For the FWT they were 50-54% in the dyslexic group and 67-71% in the control group (student t <0.05).

CONCLUSIONS

These results contribute to make evident disorders in central auditory processing in children with dyslexia. We suggest using the tests with each patient in order to elaborate a rehabilitation plan.

[Significance of auditory perceptual disorders for pediatric and adolescent psychiatric disorders]

The clinical relevance of central auditory processing disorders (CAPD) is highly controversial. The paper explicates different concepts of CAPD and reviews empirical studies of the relationship between auditory deficits and learning or psychiatric disorders. The overview of the available literature reveals that numerous authors have described subnormal auditory abilities in groups of children with developmental language disorders, dyslexia or ADHD. However, little or no relationship between the severity of clinical impairment and auditory deficits has been found. Thus auditory deficits do not appear to be causally related to learning disorders or conduct disorders. With respect to the diagnostic process the review makes clear that the validity of the diagnosis CAPD is low. There is no agreement about diagnostic criteria, and the reliability of most auditory tests in insufficient. Moreover, while an auditory training can only improve the directly trained auditory functions, there is no transfer effect to learning ability of behavior. Altogether there is little evidence for a significant relevance of CAPD in Child and Adolescent Psychiatry.

Neuroimaging features in a case of developmental central auditory processing disorder

We describe a case of developmental central auditory processing disorder (CAPD) that was diagnosed with a multidisciplinary approach including structural and functional neuroimaging. A patient with developmental CAPD was investigated using diagnostic tools of MRI and (18)F-FDG HRRT-PET as well as neuropsychology and electrophysiology. Besides impaired auditory processing, our patient also showed some impediments in supramodal, cognitive and linguistic processes. His MRI showed selective atrophy in the bilateral auditory cortices, and the PET images showed hypometabolism in the bilateral auditory cortices and the precuneus. Such a multidisciplinary diagnostic approach that includes neuroimaging methods will be helpful in differentiating developmental CAPD from other developmental cognitive disorders.