Evaluation of Selected Auditory Tests in School-Age Children Suspected of Auditory Processing Disorders

Comparison of temporal fine structure sensitivity and concurrent vowel perception between children with and without reading disability

Background: Children with reading disabilities (RD) exhibit difficulty in perceiving speech in background noise due to poor auditory stream segregation. There is a dearth of literature on measures of temporal fine structure sensitivity (TFS) and concurrent vowel perception abilities to assess auditory stream segregation in children with reading disabilities. Hence the present study compared temporal fine structure sensitivity (TFS) and concurrent vowel perception abilities between children with and without reading deficits.

Method: The present research consisted of a total number of 30 participants, 15 children with reading disabilities (RD) and fifteen typically developing (TD) children within the age range of 7-14 years and were designated as Group 1 and Group 2 respectively. Both groups were matched for age, grade, and classroom curricular instructions. The groups were evaluated for TFS and concurrent vowel perception abilities and the performance was compared using independent ‘t’ test and repeated measure ANOVA respectively.

Results: Results revealed that the children with RD performed significantly (p < 0.001) poorer than TD children on both TFS and concurrent vowel identification task. On concurrent vowel identification tasks, there was no significant interaction found between reading ability and F0 difference suggesting that the trend was similar in both the groups.

Conclusion: The study concludes that the children with RD show poor temporal fine structure sensitivity and concurrent vowel identification scores compared to age and grade matched TD children owing to poor auditory stream segregation in children with RD.

British children's performance on the listening in spatialised noise-sentences test (LISN-S)

Objective: To investigate whether British children's performance is equivalent to North American norms on the listening in spatialised noise-sentences test (LiSN-S). Design: Prospective study comparing the performance of a single British group of children to North-American norms on the LiSN-S (North American version). Study sample: The British group was composed of 46 typically developing children, aged 6-11 years 11 months, from a mainstream primary school in London. Results: No significant difference was observed between the British's group performance and the North-American norms for Low-cue, High-cue, Spatial Advantage and Total Advantage measure. The British group presented a significantly lower performance only for Talker Advantage measure (z-score: 0.35, 95% confidence interval -0.12 to -0.59). Age was significantly correlated with all unstandardised measures. Conclusion: Our results indicate that, when assessing British children, it would be appropriate to add a corrective factor of 0.35 to the z-score value obtained for the Talker Advantage in order to compare it to the North-American norms. This strategy would enable the use of LiSN-S in the UK to assess auditory stream segregation based on spatial cues.

The practices, challenges and recommendations of South African audiologists regarding managing children with auditory processing disorders

Audiologists managing children with auditory processing disorders (APD) encounter challenges that include conflicting definitions, several classification profiles, problems with differential diagnosis and a lack of standardised guidelines. The heterogeneity of the disorder and its concomitant childhood disorders makes diagnosis difficult. Linguistic and cultural issues are additional challenges faced by South African audiologists. The study aimed to describe the practices, challenges and recommendations of South African audiologists managing children with APD. A quantitative, non-experimental descriptive survey was used to obtain data from 156 audiologists registered with the Health Professions of South Africa. Findings revealed that 67% screened for APD, 42% assessed while 43% provided intervention. A variety of screening and assessment procedures were being administered, with no standard test battery identified. A range of intervention strategies being used are discussed. When the relationship between the number of years of experience and the audiologists' level of preparedness to practice in the field of APD was compared, a statistically significant difference (p = 0.049) was seen in that participants with more than 10 years of experience were more prepared to practice in this area. Those participants having qualified as speech-language therapists and audiologists were significantly more prepared (p = 0.03) to practice than the audiologists who comprised the sample. Challenges experienced by the participants included the lack of linguistically and culturally appropriate screening and assessment tools and limited normative data. Recommendations included reviewing the undergraduate audiology training programmes, reinstituting the South African APD Taskforce, developing linguistically and culturally appropriate normative data, creating awareness among educators and involving them in the multidisciplinary team.

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.

Auditory processing disorders with and without central auditory discrimination deficits

Auditory processing disorder (APD) is defined as a processing deficit in the auditory modality and spans multiple processes. To date, APD diagnosis is mostly based on the utilization of speech material. Adequate nonspeech tests that allow differentiation between an actual central hearing disorder and related disorders such as specific language impairments are still not adequately available. In the present study, 84 children between 6 and 17 years of age (clinical group), referred to three audiological centers for APD diagnosis, were evaluated with standard audiological tests and additional auditory discrimination tests. Latter tests assessed the processing of basic acoustic features at two different stages of the ascending central auditory system: (1) auditory brainstem processing was evaluated by quantifying interaural frequency, level, and signal duration discrimination (interaural tests). (2) Diencephalic/telencephalic processing was assessed by varying the same acoustic parameters (plus signals with sinusoidal amplitude modulation), but presenting the test signals in conjunction with noise pulses to the contralateral ear (dichotic(signal/noise) tests). Data of children in the clinical group were referenced to normative data obtained from more than 300 normally developing healthy school children. The results in the audiological and the discrimination tests diverged widely. Of the 39 children that were diagnosed with APD in the audiological clinic, 30 had deficits in auditory performance. Even more alarming was the fact that of the 45 children with a negative APD diagnosis, 32 showed clear signs of a central hearing deficit. Based on these results, we suggest revising current diagnostic procedure to evaluate APD in order to more clearly differentiate between central auditory processing deficits and higher-order (cognitive and/or language) processing deficits.

[Central auditory processes evaluated with psychoacoustic tests in normal children]

OBJECTIVE

To identify the natural tendencies of hits and calculate the cutoff for a test group of central auditory processes (CAP): binaural fusion, filtered words, dichotic digits, frequency patterns and duration patterns and ambient sounds in normal 5-, 7-, 9- and 11-year-old children.

MATERIAL AND METHODS

We studied 369 children (738 ears) who attend public schools in Puebla City, administering 6 CAP tests (two binaural and four monaural); we used an audiometer at 50dB SL re-threshold at 1 kHz, from a CD recorded at the CCECADET-UNAM-INR (Centre for Applied Science and Technological Development at the National Autonomous University of Mexico and the National Institute for Rehabilitation).

RESULTS

We determined the cutoff points for the six tests.

CONCLUSION

This information represents an advance in the normative standards in the field of psychoacoustic tests for CAP in Spanish and in the socio-educational context prevalent in Mexico. It is important to evaluate these results against CAP disorders.

Severity of hyperacusis predicts individual differences in speech perception in Williams Syndrome

BACKGROUND

Williams Syndrome (WS) is a neurodevelopmental disorder of genetic origin, characterised by relative proficiency in language in the face of serious impairment in several other domains. Individuals with WS display an unusual sensitivity to noise, known as hyperacusis.

METHODS

In this study, we examined the extent to which hyperacusis interferes with the perception of speech in children and adults with WS. Participants were required to discriminate words which differed in one consonant of a cluster when these contrasts were embedded in a background of noise.

RESULTS

Although the introduction of noise interfered with performance on a consonant cluster discrimination task equally in the WS and control groups, the severity of hyperacusis significantly predicted individual variability in speech perception within the WS group.

CONCLUSIONS

These results suggest that alterations in sensitivity to input mediate atypical pathways for language development in WS, where hyperacusis exerts an important influence together with other non-auditory factors.

Auditory and cognitive abilities of children suspected of auditory processing disorder (APD)

OBJECTIVE

Auditory processing disorder (APD) is typically characterised by difficulties in 'listening', particularly to speech in a noisy environment, despite normal peripheral function. In school-age children, APD has attracted considerable interest because of suspicions that it may lead to learning difficulties, especially affecting language and literacy. Here, we evaluated auditory and cognitive abilities in a group of children referred for an auditory evaluation on the grounds of a suspected auditory processing disorder (susAPD), and in age-matched children who were typically developing, in order to determine the extent to which any deficits in cognitive abilities could be related to auditory deficits.

METHODS

A battery of auditory and cognitive tests was applied to 20 susAPD school-age children, all reported as having listening/hearing problems but performing within normal limits for standard audiometric assessments. Also tested was a group of 28 age-matched controls. The auditory tasks consisted of two simple same/different discrimination tasks, one using speech, and one nonspeech. The cognitive evaluation comprised a vocabulary test, a test of grammar and four non-verbal IQ measures. Symptoms of Attention Deficit Hyperactivity Disorder (ADHD) were assessed in the susAPD group through a standardised questionnaire.

RESULTS

A significant proportion of susAPD children appeared to display genuine auditory deficits evidenced by poor performance on at least one of the auditory tasks, although about 1/3 had no detectable deficit. Children in the susAPD group scored consistently lower than the controls on cognitive measures that were both verbal (vocabulary and grammar) and non-verbal. Strikingly, susAPD children with relatively good auditory performance did not differ in cognitive ability from susAPD children with poor auditory performance. Similarly, within-group correlations between auditory and cognitive measures were weak or non-existent. Measures of ADHD did not correlate with any aspect of auditory or cognitive performance.

CONCLUSIONS

Although children suspected of having APD do show, on average, poorer performance on a number of auditory tasks, the presence or absence of an auditory deficit appears to have little impact on the development of the verbal and non-verbal skills tested here.

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.

Assessing speech perception in young children and relationships with language skills

Few materials are available to assess speech perceptual skills in young children without hearing impairments. However, children with a range of developmental conditions are at risk of speech discrimination deficits. Tasks that reliably assess speech perception skills are thus necessary for research and clinical practice. The development and application of two speech perception tests are described. Data were collected from 105 children, aged 4-5 years, attending mainstream schools, on two tasks, mispronunciation detection and non-word XAB, in quiet and in a background of multi-talker babble. Children's receptive language skills were also measured. Performance on mispronunciation detection was significantly better than on the XAB non-word task, and significantly better in quiet than in babble. Performance significantly improved with age, and speech discrimination was significantly related to receptive language abilities. Scores obtained in quiet and in babble were highly correlated and findings suggest there may be no advantage to testing in noise, except to avoid ceiling effects on performance. These tasks prove useful in the assessment of young children who may have speech discrimination deficits.

Backward and simultaneous masking in children with grammatical specific language impairment: no simple link between auditory and language abilities

PURPOSE

We investigated claims that specific language impairment (SLI) typically arises from nonspeech auditory deficits by measuring tone-in-noise thresholds in a relatively homogeneous SLI subgroup exhibiting a primary deficit restricted to grammar (Grammatical[G]-SLI).

METHOD

Fourteen children (mostly teenagers) with G-SLI were compared to age-, vocabulary-, and grammar-matched control children on their abilities to detect a brief tone in quiet and in the presence of a masking noise. The tone occurred either simultaneously with the noise or just preceding it (backward masking). Maskers with and without a spectral notch allowed estimates of frequency selectivity.

RESULTS

Group thresholds for the G-SLI children were never worse than those obtained for younger controls but were higher in both backward and simultaneous masking than in age-matched controls. However, more than half of the G-SLI group (8/14) were within age-appropriate limits for all thresholds. Frequency selectivity in the G-SLI group was normal. Within control and G-SLI groups, no threshold correlated with measures of vocabulary, grammar, or phonology. Nor did the language deficit in the G-SLI children vary with the presence or absence of auditory deficits.

CONCLUSION

The auditory processing deficits sometimes found in children with SLI appear unlikely to cause or maintain the language impairment.

Auditive Verarbeitungs- und Wahrnehmungsstörungen (AVWS)

BACKGROUND

Disorders in auditory processing have gained importance over the past 10 years. A first consensus statement defined this disorder and described several of its features. At the present stage of research, tests are missing to discriminate between normal and disturbed auditory processing development.

MATERIAL AND METHODS

A total of 142 children from the second and third grades (105 control group, 37 patients) were examined for audiological, auditory and cognitive development, as well as speech and writing abilities.

RESULTS

For the first time, normative data were defined for children from 8-9 years of age, and characteristic aspects of auditory processing disorder (APD) could be quantified.

CONCLUSION

This study supplies a test-battery with important elements for diagnosing APD under defined conditions.

The importance of modality specificity in diagnosing central auditory processing disorder

PURPOSE

This article argues for the use of modality specificity as a unifying framework by which to conceptualize and diagnose central auditory processing disorder (CAPD). The intent is to generate dialogue and critical discussion in this area of study.

METHOD

Research in the cognitive, behavioral, and neural sciences that relates to the concept of modality specificity was reviewed and synthesized.

RESULTS

Modality specificity has a long history as an organizing construct within a diverse collection of mainstream scientific disciplines. The principle of modality specificity was contrasted with the unimodal inclusive framework, which holds that auditory tests alone are sufficient to make the CAPD diagnosis. Evidence from a large body of data demonstrated that the unimodal framework was unable to delineate modality-specific processes from more generalized dysfunction; it lacked discriminant validity and resulted in an incomplete assessment. Consequently, any hypothetical model resulting from incomplete assessments or potential therapies that are based on indeterminate diagnoses are themselves questionable, and caution should be used in their application.

CONCLUSIONS

Improving specificity of diagnosis is an imperative core issue to the area of CAPD. Without specificity, the concept has little explanatory power. Because of serious flaws in concept and design, the unimodal inclusive framework should be abandoned in favor of a more valid approach that uses modality specificity.

Auditive Verarbeitungs- und Wahrnehmungsstörungen

The consensus statement published by the German Society for Phoniatry and Paedaudiology in the year 2000 has been revised and actualized. The revised version takes into account current scientific and clinical findings. Aspects of the definition of auditory processing disorders (APD) are described extensively. These include symptoms, anamnestic information and diagnostic steps (preliminary examinations, subjective and objective audiological procedures). APD can appear in different forms, some of which can be classified within subtypes. Furthermore, factors which need to be considered in order to differentiate between APD and other diseases are specified. Therapeutic intervention possibilities which are rated according to their prognostic values conclude the article.