Behavioral profiles associated with auditory processing disorder and specific language impairment

PurposeTo describe and compare behavioral profiles associated with auditory processing disorder (APD) and specific language impairment (SLI) in school-age children.MethodThe participants in this cross-sectional observational study were 64 children (mean age 10.1 years) recruited through clinician referrals. Thirty-five participants had a clinical diagnosis of APD and 29 were receiving services for language impairment. Participants completed 18 behavioral measures of spoken language, auditory processing, reading, memory, and motor speed. Responses were used to classify children as affected/not affected with APD, and affected/not affected with SLI. Comparisons were made between children with and without an APD diagnosis, and between children assigned to the APD/not APD and SLI/not SLI groups. Agreement between clinical status and test-based classifications is also reported.ResultsThere were no group mean differences between children with and without a clinical diagnosis of APD. Group mean differences on Cube Design and reading fluency were observed for children classified as APD/not APD; and group mean differences on nonword repetition, spatial working memory, and two auditory processing tests were observed for children classified as SLI/not SLI.ConclusionsThe behavioral profiles of children with APD and SLI were very similar. Although group mean differences were found, they were difficult to interpret in terms of current theories.Learning outcomes: The reader will be able to: (1) describe similarities and differences found between children with SLI and children with APD and (2) discuss assessment problems posed by overlapping behavioral characteristics of SLI and APD.     

Assessment of the efferent auditory system in children with suspected auditory processing disorder: the Middle ear muscle reflex and contralateral inhibition of OAEs

Objective: To determine whether children aged 7 to 12?years with listening difficulties show objective evidence for efferent auditory function based on measurements of medial olivo-cochlear and middle ear muscle reflexes.

Design: Click-evoked otoacoustic emissions recorded with and without contralateral broadband noise and ipsilateral and contralateral tonal (1000, 2000?Hz) middle ear muscle reflex thresholds were examined.

Study sample: 29 children diagnosed with suspected auditory processing disorder (APD) and a control group of 34 typically developing children participated in this study.

Results: Children with suspected APD had poorer performance on auditory processing tests than the control group. Middle ear muscle reflex thresholds were significantly higher at 2000?Hz in the suspected APD group for contralateral stimulation. MOC inhibition effects did not differ between APD and control groups.

Conclusions: This research supports earlier studies showing altered acoustic reflexes in children with APD. No group differences were found for the MOC reflex measures, consistent with some earlier studies in children with APD.     

Association between language development and auditory processing disorders

IntroductionIt is crucial to understand the complex processing of acoustic stimuli along the auditory pathway; comprehension of this complex processing can facilitate our understanding of the processes that underlie normal and altered human communication.AimTo investigate the performance and lateralization effects on auditory processing assessment in children with specific language impairment (SLI), relating these findings to those obtained in children with auditory processing disorder (APD) and typical development (TD).Material and methodsProspective study. Seventy-five children, aged 6-12 years, were separated in three groups: 25 children with SLI, 25 children with APD, and 25 children with TD. All went through the following tests: speech-in-noise test, Dichotic Digit test and Pitch Pattern Sequencing test.ResultsThe effects of lateralization were observed only in the SLI group, with the left ear presenting much lower scores than those presented to the right ear. The inter-group analysis has shown that in all tests children from APD and SLI groups had significantly poorer performance compared to TD group. Moreover, SLI group presented worse results than APD group.ConclusionThis study has shown, in children with SLI, an inefficient processing of essential sound components and an effect of lateralization. These findings may indicate that neural processes (required for auditory processing) are different between auditory processing and speech disorders.     

Contralateral suppression of otoacoustic emissions in a clinical sample of children with auditory processing disorder

Objective: The suppression of evoked otoacoustic emissions (EOAE) may serve as a clinical tool to evaluate the medial olivocochlear (MOC) reflex, which is thought to aid speech discrimination (particularly in noise) by selectively inhibiting cochlear amplification. The present study aimed to determine if contralateral transient evoked otoacoustic emission (TEOAE) suppression was present in a clinical sample of children with listening difficulties with and without auditory processing disorder (APD).

Design: A three-group, repeated measure design was used.

Study sample: Forty three children aged 8–14?years underwent an auditory processing assessment and were divided into three groups: children with reported listening difficulties with APD, children with reported listening difficulties without APD, and children with normal hearing. APD was defined as per British Society of Audiology.

Results: TEOAE suppression was present in all three participant groups. No significant group, age or ear effects were observed for TEOAE suppression in dB or as a normalised index.

Conclusion: Contralateral TEOAE suppression method could not be used as a clinical tool to identify APD in this study’s participating children and did not support the hypothesised link between reduced MOC function and general listening difficulties in background noise in children with or without APD.     

Electrophysiological characteristics in children with listening difficulties,with or without auditory processing disorder

Abstract

Objective: To determine if the auditory middle latency responses (AMLR), auditory late latency response (ALLR) and auditory P300 were sensitive to auditory processing disorder (APD) and listening difficulties in children, and further to elucidate mechanisms regarding level of neurobiological problems in the central auditory nervous system.

Design: Three-group, repeated measure design.

Study sample: Forty-six children aged 8–14 years were divided into three groups: children with reported listening difficulties fulfilling APD diagnostic criteria, children with reported listening difficulties not fulfilling APD diagnostic criteria and normally hearing children.

Results: AMLR Na latency and P300 latency and amplitude were sensitive to listening difficulties. No other auditory evoked potential (AEP) measures were sensitive to listening difficulties, and no AEP measures were sensitive to APD only. Moderate correlations were observed between P300 latency and amplitude and the behavioural AP measures of competing words, frequency patterns, duration patterns and dichotic digits.

Conclusions: Impaired thalamo-cortical (bottom up) and neurocognitive function (top-down) may contribute to difficulties discriminating speech and non-speech sounds. Cognitive processes involved in conscious recognition, attention and discrimination of the acoustic characteristics of the stimuli could contribute to listening difficulties in general, and to APD in particular.     

Psychometric evaluation of children with suspected auditory processing disorders (APDs) using a parent-answered survey

Difficulty with auditory processing in children is of increasing interest but is the subject of some controversy in the literature. This paper describes a psychometric evaluation of differences between children with suspected auditory processing disorders (APDs) and a control group, using a parent-answered questionnaire. The questionnaire comprised 51 items associated with auditory processing as well as speech/language- and behaviour-related areas. It was found that most of the items separated significantly (p?<?0.01) between the children with suspected APDs and the control group. A factor analysis identified seven components (speech understanding in demanding situations, speech/language abilities, general behavioural issues, reactions to questions and demands, discrimination of speech sounds, musical cues, loudness perception) underlying the contrasts between the two study populations. The examination might serve as a basis for the development of an APD-related questionnaire. However, the validity of such a questionnaire is questionable at present, since APD is not very well specified, and standardized diagnostic tests are lacking.     

A systematic review of electrophysiological outcomes following auditory training in school-age children with auditory processing deficits

Abstract

Objective: To systematically review the peer-reviewed literature on electrophysiological outcomes following auditory training (AT) in school-age children with (central) auditory processing disorder ([C]APD). Design: A systematic review. Study sample: Searches of 16 electronic databases yielded four studies involving school-aged children whose auditory processing deficits had been confirmed in a manner consistent with and and compared to a treated and/or an untreated control group before and after AT. A further three studies were identified with one lacking a control group and two measuring auditory processing in a manner not consistent with and . Results: There is limited evidence that AT leads to measurable electrophysiological changes in children with auditory processing deficits. Conclusion: The evidence base is too small and weak to provide clear guidance on the use of electrophysiological outcomes as a measure of AT outcomes in children with auditory processing problems. The currently limited data can only be used to suggest that click-evoked AMLR and tone-burst evoked auditory P300 might be more likely to detect such outcomes in children diagnosed with (C)APD, and that speech-evoked ALLR might be more likely to detect phonological processing changes in children without a specific diagnosis of (C)APD.     

Hemispheric laterality assessment with dichotic digits testing in dyslexia and auditory processing disorder

Abstract

One of the widely used tests to evaluate functional asymmetry of cerebral hemispheres is the dichotic listening test with the usually prevailing right ear advantage. The current study aims at assessing hemispheric laterality in an adult sample of individuals with dyslexia, with auditory processing disorder (APD), and adults experiencing comorbidity of the two mentioned disorders against a control group with normal hearing and absence of learning disabilities. Results exhibit a right hemispheric dominance for the control and APD group, a left hemispheric dominance for the group diagnosed with both dyslexia and APD, and absence of dominance for the dyslexia group. Assessment of laterality was repeatable and produced stable results, indicating a true deficit. A component of auditory processing, specifically the auditory performance in competing acoustic signals, seems to be deficient in all three groups, and laterality of hemispheric functions influenced at least for auditory-language stimuli in the two of the three groups, one being adults with dyslexia and the other being adults with comorbidity of dyslexia and APD.

Sumario

Una de las pruebas más ampliamente utilizadas para evaluar la asimetría funcional de los hemisferios cerebrales es la prueba de escucha dicótica, generalmente con la resultante ventaja del oído derecho. El presente estudio tiene como objetivo evaluar la lateralidad hemisférica en una muestra de adultos con dislexia, con desórdenes del procesamiento auditivo (APD) y adultos con ambos problemas vs un grupo control de normoyentes sin alteraciones del aprendizaje. Los resultados muestran una dominancia del hemisferio derecho para el grupo control y el grupo con APD y una dominancia del hemisferio izquierdo para el grupo diagnosticado con ambas condiciones, y ninguna dominancia del grupo de dislexia. La evaluación de la lateralidad fue repetible y produjo resultados estables, indicando un déficit verdadero. Un componente del procesamiento auditivo, específicamente el desempeño auditivo bajo señales acústicas competitivas, parece ser deficiente en los tres grupos y las funciones de lateralidad hemisférica se vieron influidas al menos por los estímulos auditivos lingüísticos en dos de los tres grupos; el de adultos con dislexia y el de adultos con ambas condiciones, dislexia y APD.     

A randomized control trial of interventions in school-aged children with auditory processing disorders

Objective: The primary purpose of the study was to compare intervention approaches for children with auditory processing disorder (APD): bottom-up training including activities focused on auditory perception, discrimination, and phonological awareness, and top-down training including a range of language activities. Another purpose was to determine the benefits of personal FM systems. Design: The study is a randomized control trial where participants were allocated to groups receiving one of the two interventions, with and without personal FM, or to the no intervention group. The six-week intervention included weekly one-hour sessions with a therapist in the clinic, plus 1–2 hours per week of parent-directed homework. Study sample: 55 children (7 to 13 years) with APD participated in the study. Intervention outcomes included reading, language, and auditory processing. Results: Positive outcomes were observed for both training approaches and personal FM systems on several measures. Pre-intervention nonverbal IQ, age, and severity of APD did not influence outcomes. Performance of control group participants did not change when retested after the intervention period. Conclusions: Both intervention approaches were beneficial and there were additional benefits with the use of personal FM. Positive results were not limited to the areas specifically targeted by the interventions.     

A long-term follow-up of children and adolescents referred for assessment of auditory processing disorder

Objective: This study investigated whether young adults (between 18 and 30 years at the time of the project) who were assessed for auditory processing disorder (APD) in childhood (between 7 and 16 years) experience persistence of listening and communication difficulties. Design: Participants completed a mixed methods questionnaire focusing on common areas of complaint in APD and two open-ended questions exploring participants’ past and present experiences with listening and communication difficulties. Study sample: Ninety-seven of the 722 potential participants returned completed questionnaires, of whom 66 had been diagnosed with APD (APD group) at the time of their auditory processing assessment and 31 had not met diagnostic criteria (NAPD group) at that time. Results: Substantial commonality was noted in the reported listening and communication difficulties between the APD and NAPD participants. Volunteered comments aggregated into four major content themes which included: listening and communication difficulties; participants’ sense of self; change; and participation. Members of the APD group reported greater communication difficulty than NAPD group members, irrespective of environmental listening conditions. Conclusions: Young adults with a prior referral for, and in some cases a diagnosis of, APD as children continue to experience auditory processing difficulties across a range of daily situations.     

The relation between working memory capacity and auditory lateralization in children with auditory processing disorders

ObjectiveAuditory processing disorder (APD) describes a complex and heterogeneous disorder characterized by poor speech perception, especially in noisy environments. APD may be responsible for a range of sensory processing deficits associated with learning difficulties. There is no general consensus about the nature of APD and how the disorder should be assessed or managed. This study assessed the effect of cognition abilities (working memory capacity) on sound lateralization in children with auditory processing disorders, in order to determine how “auditory cognition” interacts with APD.MethodsThe participants in this cross-sectional comparative study were 20 typically developing and 17 children with a diagnosed auditory processing disorder (9–11 years old). Sound lateralization abilities investigated using inter-aural time (ITD) differences and inter-aural intensity (IID) differences with two stimuli (high pass and low pass noise) in nine perceived positions. Working memory capacity was evaluated using the non-word repetition, and forward and backward digits span tasks. Linear regression was employed to measure the degree of association between working memory capacity and localization tests between the two groups.ResultsChildren in the APD group had consistently lower scores than typically developing subjects in lateralization and working memory capacity measures. The results showed working memory capacity had significantly negative correlation with ITD errors especially with high pass noise stimulus but not with IID errors in APD children.ConclusionsThe study highlights the impact of working memory capacity on auditory lateralization. The finding of this research indicates that the extent to which working memory influences auditory processing depend on the type of auditory processing and the nature of stimulus/listening situation.     

Spectral ripple discrimination in children with auditory processing disorder

Abstract

Objective: The purpose of this study was to examine developmental trends in spectral ripple discrimination (SRD) and to compare the performance of typically developing children to children with auditory processing disorder (APD).

Study design: Cross-sectional study.

Study sample: Fifteen children with APD, as well as 17 typically developing children and 14 adults reporting no listening or academic difficulties participated.

Results: Typically developing children showed poor SRD thresholds compared to adults, indicating prolonged maturation of spectral shape recognition. Both typically developing children and APD children showed a maturational trend in SRD, but a General Linear Model fit to their thresholds showed that children with APD displayed SRD thresholds that were significantly poorer than those of typically developing children when controlling for age. This suggests that in APD children, SRD maturation lags behind typically developing children.

Conclusion: Poor spectral ripple discrimination may explain some of the listening difficulties experienced by children with APD.     

The Danish test battery for auditory processing disorder evaluated with patient and control data

Abstract

Objective: This study evaluates the Danish test battery for auditory processing disorder (APD). The battery consists of four behavioural tests, two speech and two non-speech stimuli tests. The evaluation includes determination of: (1) new cut-off values (pass-fail criteria), (2) the sensitivity and the specificity of the entire test battery and (3) the failure rate of different test combinations.

Design: For each test in the battery, cut-off values were determined using the weighted Youden index. Applying the newly derived cut-off values, the distribution of failing specific test combinations was determined.

Study sample: A group of 112 children diagnosed with APD (57 boys, 55 girls, aged 6–16?years) and a control group containing 158 children without auditory problems (75 boys, 83 girls, aged 6–16?years).

Results: Cut-off values for different weights of the sensitivity and the specificity have been determined. Using the criterion that at least two tests have to be failed for APD to be suspected, the sensitivity and the specificity of the entire test battery were 95.3% and 91.6%, respectively. Some test combinations were found to have higher failure rates than others.

Conclusions: Due to the high sensitivity and specificity the test battery has good predictive value in APD assessment.     

Cognitive evoked potentials and central auditory processing in children with reading and writing disorders

Learning disorders are often magnified by auditory processing disorders (APD).ObjectiveThis paper aims to verify whether individuals with reading and writing disorders and P300 latencies above the average also present altered Staggered Spondaic Word (SSW) and speech-in-noise test results suggestive of APD.Materials and MethodsThis is a cross-sectional cohort study. Twenty-one individuals with reading and writing disorders aged between 7 and 14 years were enrolled.ResultsAll subjects had normal findings on ENT examination, audiological tests, and brainstem auditory evoked potentials. The average P300 latency (334,25 ms) of all patients was picked as a cutoff point to divide the subjects into two groups: group A with latencies above 335 ms, and group B with latencies below 335 ms. Individuals in group A underwent SSW and speech-in-noise testing.ConclusionAltered results in the SSW and speech-in-noise tests suggestive of APD were found in the group of individuals with reading and writing disorders with P300 latencies above 335 ms.     

Auditory processing disorders: Relationship to cognitive processes and underlying auditory neural integrity

Background

Auditory processing disorder (APD) in children has been reported and discussed in the clinical and research literature for many years yet there remains poor agreement on diagnostic criteria, the relationship between APD and cognitive skills, and the importance of assessing underlying neural integrity.

Purpose

The present study used a repeated measures design to examine the relationship between a clinical APD diagnosis achieved with behavioral tests used in many clinics, cognitive abilities measured with standardized tests of intelligence, academic achievement, language, phonology, memory and attention and measures of auditory neural integrity as measured with acoustic reflex thresholds and auditory brainstem responses.

Method

Participants were 63 children, 7–17 years of age, who reported listening difficulties in spite of normal hearing thresholds. Parents/guardians completed surveys about the child's auditory and attention behavior while children completed an audiologic examination that included 5 behavioral tests of auditory processing ability. Standardized tests that examined intelligence, academic achievement, language, phonology, memory and attention, and objective tests auditory function included crossed and uncrossed acoustic reflex thresholds and auditory brainstem responses (ABR) were also administered to each child.

Results

Forty of the children received an APD diagnosis based on the 5 behavioral tests and 23 did not. The groups of children performed similarly on intelligence measures but the children with an APD diagnosis tended to perform more poorly on other cognitive measures. Auditory brainstem responses and acoustic reflex thresholds were often abnormal in both groups of children.

Summary

Results of this study suggest that a purely behavioral test battery may be insufficient to accurately identify all children with auditory processing disorders. Physiologic test measures, including acoustic reflex and auditory brainstem response tests, are important indicators of auditory function and may be the only indication of a problem. The results also suggest that performance on behavioral APD tests may be strongly influenced by the child's language levels.     

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

Abstract

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.     

The Auditory Processing Domains Questionnaire (APDQ): Brazilian–Portuguese version

ObjectiveThe present study aimed to determine the fidelity, reliability, and internal validity of the APDQ when translated from English to Brazilian–Portuguese language.MethodsThe first phase included the APDQ translation into Brazilian–Portuguese including forward translation, translation assessment and back-translation in a group of 10 students. The second phase involved establishing the internal consistency and reliability of the APDQ Brazilian–Portuguese version. Data was collected from 66 students without any risk factor for auditory processing disorder. Subjects were divided into a younger group (7–10 yrs) and an older group (11–17 yrs).ResultsAll items showed appropriate quality in terms of translation. In determining internal consistency, Cronbach's alpha in subscales of auditory processing, attention and language was found to be 0.93, 0.85 and 0.74, respectively. Intraclass Correlation Coefficient for total score was 0.95, ensuring a strong test-retest reliability.ConclusionThe Brazilian–Portuguese version of the APDQ has favorable translation quality, internal validity and reliability. It is now ready for continued study as a differential screening tool for 7- to 17-year-old Brazilian children with listening difficulties who are at risk for auditory processing disorder, attention deficits and language learning challenges.     

Nonmodularity of the central auditory nervous system: implications for (central) auditory processing disorder

This response to A. T. Cacace and D. J. McFarland (2005) identifies points of agreement and disagreement regarding the concept of modularity in the diagnosis of (central) auditory processing disorder [(C)APD]. We concur that the evaluation of (C)APD must take into consideration the influence of higher order global or pansensory issues on performance on tests of central auditory function. To accomplish this goal, multidisciplinary (e.g., multimodal) testing is an integral part of differential diagnosis of (C)APD. We also agree that the efficiency of diagnostic tests of (C)APD should not be evaluated by imprecise criteria [e.g., "presumed" or "suspected" (C)APD], which do not provide accurate measures of the true sensitivity and specificity of these tests. Our conceptualization and recommendations for clinical practice in this area diverge, however, from that of Cacace and McFarland in a number of pivotal ways. Based on the current limitations of multimodal assessment relative to issues related to scope of practice and test efficiency, as well as the accumulated basic science and clinical literature that demonstrates the nonmodularity and interactive organization of the brain, we recommend use of the sensitized test battery of the central auditory nervous system (CANS) in combination with multidisciplinary testing to differentially diagnose (C)APD and to guide treatment of the disorder. We assert that sensitivity and specificity measures derived from individuals with well-circumscribed lesions of the CANS provide an important guide to establishing the validity of central auditory diagnostic tests. We note that researchers in the area of auditory science and (C)APD must acknowledge the challenges of the clinical arena, and we encourage their continued help to develop diagnostic tools that are both efficient and practical for the differential diagnosis of (C)APD. We conclude that our approach, which combines multidisciplinary evaluation and specific tests of central auditory function that have demonstrated sensitivity and specificity for disorders of the CANS, allows us to identify (and thus rehabilitate) the auditory deficits present in individuals with (C)APD in its "purest" form. It also permits the identification and rehabilitation of auditory deficits in individuals who exhibit auditory perceptual problems that coexist with other processing problems, while ruling out those who perform poorly on auditory tests because of a global, supramodal problem involving cognition, attention, language, memory, or related skills.     

Psychometric evaluation of children with suspected auditory processing disorders (APDs) using a parent-answered survey

Difficulty with auditory processing in children is of increasing interest but is the subject of some controversy in the literature This paper describes a psychometric evaluation of differences between children with suspected auditory processing disorders (APDs) and a control group, using a parent-answered questionnaire. The questionnaire comprised 51 items associated with auditory processing as well as speech/language- and behaviour-related areas. It was found that most of the items separated significantly (p<0.01) between the children with suspected APDs and the control group. A factor analysis identified seven components (speech understanding in demanding situations, speech/language abilities, general behavioural issues, reactions to questions and demands, discrimination of speech sounds, musical cues, loudness perception) underlying the contrasts between the two study populations. The examination might serve as a basis for the development of an APD-related questionnaire. However, the validity of such a questionnaire is questionable at present, since APD is not very well specified, and standardized diagnostic tests are lacking.