Evaluation of a cognitive test battery in young and elderly normal-hearing and hearing-impaired persons

A cognitive test battery sensitive to processes important for speech understanding was developed and investigated. Test stimuli are presented as text or in an auditory or audiovisual modality. The tests investigate phonologic processing and verbal information processing. Four subject groups, young/elderly with normal-hearing and young/elderly with hearing impairment, each including 12 subjects, participated in the study. The only significant effect in the text modality was an age effect in the speed of performance, seen also in the auditory and audiovisual modalities. In the auditory and audiovisual modalities, the effects of hearing status and modality were seen in accuracy parameters. Interactions between hearing status and modality, both in accuracy and in reaction times, show that hearing-impaired subjects have difficulties without visual cues. Performing the test battery in noise made the tasks more difficult, especially in the auditory modality and for the elderly, affecting both accuracy and speed. Test-retest measurements showed learning effects and a modality-dependent variability. The test battery has proven useful in assessing the relative contribution of different input signals and the effects of age, hearing impairment, and visual contribution on functions important for speech processing.     

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.     

Development of auditory processing in 6-12-year-old children: a longitudinal study

The development of auditory processing in children was investigated in a longitudinal study. A group of 20 children with normal cognitive and language development underwent several auditory tests at the ages of 6, 7, 8, 10 and 12 years. At the age of 10 years, three subjects were lost to follow-up, as was one more subject at the age of 12 years. The auditory performance of the children was compared to the performance of a group of 20 adults. The auditory test battery consisted of a speech-in-noise test, a filtered speech test, a binaural fusion test and two auditory sequencing tests. At the ages of 6, 7 and 8 years, data on the performance on an auditory word discrimination test, an auditory synthesis test, an auditory closure test and a number recall test were also obtained. All auditory tests except the speech-in-noise test showed a clear effect of age on the performance of children. Our data suggest that maturational effects play an important role in auditory processing (at least) up to an age of 12-13 years. Correlations between the tests are in general not indicative of large amounts of overlap between the different tests. Factor analysis shows that three factors account for 68-70% of explained variance, with the three factors contributing equally. A composite score obtained by averaging all (sub)test scores can be used next to the individual test scores to describe the development of auditory processing abilities in children.     

Test battery assessment of auditory perceptual dysfunction in children

Seven central auditory tests were administered to 22 children, 8 to 10 years of age, considered as having auditory processing deficits. Analysis of the results indicated some tests to be significantly more sensitive than others in detecting auditory processing problems. Findings also demonstrated the advantages of a test battery over a single test and the value of employing central auditory tests for the detection of auditory processing difficulties in children. In addition, considerations for proper test battery construction are discussed in light of the results from this study.     

Central auditory processing assessment

As the acoustic information travels within the central auditory nervous system, the processing of the signal undergoes several levels of serial and parallel "bottom-up" processing influenced by high level cognitive "top-down" processes. Because the multiple location of the operational sites, the central auditory deficits are frequently quite subtle and need a test battery approach to be identified. Each of the four principal processes has at least to be tested: the closure task, the dichotic ability, the temporal ordering task and the binaural interaction function. The purpose of this review is to provide an overview of the psychoacoustic test procedures of identifying lesions or dysfunction's in the central auditory system.     

Normal and learning disabled children's central auditory processing skills: an experimental test battery

The performance of normal children (N = 13) and learning disabled children (N = 26) on an experimental battery of central auditory processing (CAP) tasks was examined. The battery included low-pass filtered speech (LPFS), binaural fusion (BF), time-compressed speech (TC), and dichotic monosyllables (DM) tests. The learning disabled subjects were classified as having normal (LD/N) or significantly impaired (LD/LD) auditory perceptual skills on the basis of a pretest battery of auditory language tests. The normal (N/N) subjects and nonauditory learning disabled (LD/N) subjects tended to perform alike across measures. The auditorily impaired (LD/LD) subjects tended to perform significantly poorer than their normal agemates. The results emphasized the heterogeneity of the learning disabled population. In addition, the results suggested a potentially useful "at risk" criterion when a CAP test battery is used in the assessment of auditory perceptual impairment among children.     

Assessment of auditory processing in 6-year-old language-impaired children

The performance of a group of twenty 6-year-old children with specific language impairment (SLI) on several behavioural auditory tests was compared to that of a group of twenty age-matched control children. The auditory test battery used in this study consisted of the following tests: a speech-in-noise test, a filtered speech test, a binaural fusion test, a frequency pattern test, a duration pattern test, a temporal integration test, an auditory word discrimination test, an auditory synthesis test, an auditory closure test and a number recall test. Our results show that the SLI children obtained scores on almost all tests that were significantly lower than those of the control group. Many of the basic auditory processing measures in our test battery correlated significantly with receptive and language scores, suggesting a (causal) relationship between auditory processing and language proficiency. Results from discriminant function analyses do not warrant deleting one or more tests from the test battery yet (with the exception of the auditory synthesis test and the temporal integration test, for which we did not find significant group effects). At present, we are conducting experiments with older (SLI and control) children and adults to find whether the significant performance deficits of the SLI children are also found in older SLI children, and to determine the influence of maturational effects on these auditory tests.     

Ten(HL)-test results and psychophysical tuning curves for subjects with auditory neuropathy

The purpose of the present study was to examine possible signs of long-term cognitive and/or central auditory sequelae seven to eleven years after a closed head injury (CHI) of sufficient severity to cause scull fracture and/or brain contusion. Another purpose was that this investigation should be carried out in a group of recovered trauma victims with, to the individual, no known or minimal sequelae.

A computer-based set of five cognitive tests and three central auditory tests were used in a group of formerly brain-injured patients who considered themselves as well recovered. Most of the participants did not report any signs of cognitive or auditory impairment. Tests of working memory capacity, verbal information processing speed, phonological processing and verbal inference-making ability were used. Auditory brain response (ABR), distorted speech audiometry (interrupted speech), and phase audiometry were used to test central auditory function. The initial severity of brain damage, i.e. status when the patient arrived at the emergency ward, was estimated with Swedish Reaction Level Scale (RLS).

Cognitive shortcomings after CHI were demonstrated in a high percentage (59%, 13/22) of the cases seven to eleven years after the injury. Central auditory processing disorders (APD) were also demonstrated in a fairly high percentage (58%, 11/19) of the subjects. None of the correlations between RLS and the results on cognitive and central auditory tests reached statistical significance. However, there was a correlation between cognitive performance and the results on the central auditory tests used in this investigation. Eighty percent (8/10) of those participants with pathologies on ABR and/or phase audiometry and/or IS also failed on one or more of the cognitive tasks, compared to 44% (4/9) among those with no signs of APD.

It is possible, many years after CHI, to observe cognitive shortcomings and APD in a relatively high percentage of CHI cases that are subjectively considered to be fairly well recovered. The cognitive tasks used in the study have proved to be a sensitive method to discover cognitive impairments. Long-term cognitive sequelae and APD could not be predicted from RLS scores.     

The effect of mild hearing impairment on auditory processing tests

The application of auditory processing tests to patients with sensorineural hearing loss is controversial. Several studies have shown that it is difficult to separate peripheral from central hearing processes. In the present study, a Dutch auditory processing test battery was administered to 24 subjects with mild, relatively flat, symmetrical sensorineural hearing loss. Tests were administered twice; the second time, the presentation level in four out of the six tests was adjusted according to the speech reception threshold. The scores of the hearing-impaired subjects were significantly poorer than those of the subjects with normal hearing on five out of the six tests, even with the adjusted presentation level. Significant correlations were found between test scores and PTA (pure-tone average); scores on words-in-noise, filtered-speech and binaural-fusion tests were additionally corrected according to PTA. In contrast to previous studies in the literature, the present dichotic-digit and pattern-recognition tests were greatly influenced by mild hearing loss. Therefore, this auditory processing test battery cannot readily be used to diagnose central auditory processing disorders in patients with flat sensorineural hearing loss. At least, both adjustment of presentation level and additional correction are needed.     

An update on professional education and clinical practices in central auditory processing

Results of an online questionnaire probing audiologists' professional education and clinical practices in central auditory processing and its disorders are reported. Respondents demonstrated scant knowledge of the efficiency of central auditory tests and procedures; however, they were rather consistent in reporting more frequent use of tests and procedures they rated as more efficient. Many of the tests and procedures (including electrophysiologic measures) reported as most frequently used are among those cited in the literature as having good sensitivity and specificity. Respondents recognized the audiologist's treatment responsibilities in the areas of environmental accommodations and assistive listening devices; however, less than half of the respondents judged auditory training to fall within the audiologist's purview. Comparison with a similar study published in 1998 revealed an increase in respondents' academic preparation in (C)APD, with little change in clinical preparation, and use of a more efficient central auditory test battery.     

Auditory brain stem response and central auditory test findings for patients with brain stem lesions: A preliminary report

Basic audiologic data, as well as five selected measures of the auditory brain stem response, and results from seven central auditory tests were obtained from ten adult subjects with a variety of brain stem lesions. The ABSR measures included latency, waveform morphology, amplitude ratio, presentation rate and intensity function. The central tests administered were competing sentences, rapidly alternating speech, binaural fusion, staggered spondaic words, dichotic digits, frequency patterns and low pass filtered speech. Both procedures (ABSR and C.A.T. battery) were highly sensitive to brain stem lesions in the study group as a whole, but showed some limitations for individual subjects. The data also indicated the value of employing a test battery and multiple electrophysiologic measures as opposed to single indices of auditory performance. Findings on individual central tests and ABSR measures are reported, as well as data on laterality effects.     

疑似听觉处理障碍儿童案例研究

目的本文介绍了中枢听觉功能测试方法，探讨了对听觉处理障碍儿童的诊断和处理原则。方法选择3例疑似听觉处理障碍儿童作为研究案例，进行系统的听力学，教育心理学、言语病理学测试和听觉中枢处理评估。结果在随机间隔探测测试和空间噪音听力测试（Iistening in spatializecl noise test，LISN）中，得分低于同龄组的平均值超过5个标准差；高一提示信号的LISN测试结果显示，数值低于平均值超过2个标准差。结论中枢听觉处理测试序列说明此3例儿童存在双耳听觉处理缺陷。通过改善教室的信噪比，应用听觉闭合训练、听觉定位和辨别训练，加强语言处理技能训练，能够使这3名儿童受益。     

Prevalence of central auditory processing (CAP) abnormality in an older Australian population: the Blue Mountains Hearing Study

Age-related central auditory processing (CAP) abnormality has been described in many studies with widely varying prevalence reported. To date, there has been only one population study to report prevalence for this age-related condition, and these rates were significantly lower than in reports from clinical studies. The present study reports findings from a recent population study in which 2015 Australians aged 55 years and older living in a defined area west of Sydney were assessed with a battery of behavioral and electrophysiological auditory tests. This battery included speech measures from which a high overall prevalence rate (76.4%) of CAP abnormalities was found, in keeping with previous clinical studies. While gender differences were dependent on the test measure, the number of abnormal test outcomes increased systematically with age. Hearing loss and abnormal cognitive function, however, did not systematically increase with number of abnormal test outcomes.     

Central auditory processes and test measures: ASHA 1996 revisited

The theoretical issues surrounding central auditory processing disorders (CAPD) are reviewed here, especially with reference to the central auditory behavioral processes and the auditory test measures as prescribed in the ASHA (1996, American Journal of Audiology, 5(2), 41-54) statement on CAPD. A simplified nomenclature is recommended that directly relates process and test measure to facilitate the diagnostic process in CAPD. This new terminology closely follows the ASHA (1996, American Journal of Audiology, 5(2), 41-54) document, but provides some refinement based on recent research in CAPD. To support this recommendation, a confirmatory factor analysis (CFA) was applied to the findings of Domitz and Schow (2000, American Journal of Audiology), who proposed use of a battery of CAPD tests, the Multiple Auditory Processing Assessment (MAPA) for testing school children. The CFA was found to reinforce the four-factor model, which clearly emerged in the exploratory factor analysis of Domitz and Schow. The model was found to be reasonably consistent even when subtests from the SCAN were included in the analysis. Refinement and revision of ASHA (1996, American Journal of Audiology, 5(2), 41-54) is recommended to facilitate diagnosis, subclassification, and intervention for CAPD.     

The effect of midline petrous apex lesions on tests of afferent and efferent auditory function

OBJECTIVES: Historically, audiological procedures have focused on the assessment of the afferent (ascending) cochlear-VIIIth nerve system and have, for the most part, ignored the efferent (descending) auditory system. We report afferent and efferent auditory test results for two cases with a cholesterol cyst of the right petrous apex; one lesion involves the afferent segment of the auditory system, and the second lesion involves both the afferent and efferent segments of the auditory system. These "natural experiments" provide a unique opportunity to study the effect of a space-occupying lesion of the petrous apex on afferent and efferent function of the auditory system. DESIGN: Transient evoked otoacoustic emission (TEOAE) suppression studies were performed to assess the effect of the cholesterol cyst on the efferent system of the two cases. In addition, three complementary afferent tests of brain stem auditory function were administered: 1) acoustic reflex thresholds (ARTs); 2) masking level difference (MLD); and 3) auditory brain stem response (ABR). These tests are complementary because the superior olivary complex (SOC) is involved not only in the mediation of the sound evoked efferent reflex assessed in TEOAE suppression, but in the mediation of the ARTs, the MLD, and the ABR. RESULTS: The two cases with midline petrous apex lesions, one not involving the VIII-cochlear efferent auditory system, differed from each other with regards to TEOAEs suppression, and ARTs. Specifically, the case with only afferent involvement produced normal TEOAE suppression, a normal MLD, normal ARTs, and abnormal waves III and V of the ABR, whereas the case with both afferent and efferent involvement produced abnormal TEOAE suppression, a normal MLD, abnormal ARTs, and abnormal waves III and V of the ABR. CONCLUSIONS: These cases illustrate that although several auditory tests can be mediated within the same or adjacent anatomical structures, i.e., the SOC, they may not be equally affected by the same lesion due to different physiology. Further, the TEOAE suppression paradigm is a clinically relevant test to assay the sound evoked efferent reflex that is mediated by the medial olivocochlear system of the SOC.     

Random Gap Detection Test (RGDT) performance of individuals with central auditory processing disorders from 5 to 25 years of age

Objective

The aim of the present study was to assess the auditory temporal resolution ability in individuals with central auditory processing disorders, to examine the maturation effect and to investigate the relationship between the performance on a temporal resolution test with the performance on other central auditory tests.

Methods

Participants were divided in two groups: 131 with Central Auditory Processing Disorder and 94 with normal auditory processing. They had pure-tone air-conduction thresholds no poorer than 15 dB HL bilaterally, normal admittance measures and presence of acoustic reflexes. Also, they were assessed with a central auditory test battery. Participants who failed at least one or more tests were included in the Central Auditory Processing Disorder group and those in the control group obtained normal performance on all tests. Following the auditory processing assessment, the Random Gap Detection Test was administered to the participants. A three-way ANOVA was performed. Correlation analyses were also done between the four Random Gap Detection Test subtests data as well as between Random Gap Detection Test data and the other auditory processing test results.

Results

There was a significant difference between the age-group performances in children with and without Central Auditory Processing Disorder. Also, 48% of children with Central Auditory Processing Disorder failed the Random Gap Detection Test and the percentage decreased as a function of age. The highest percentage (86%) was found in the 5-6 year-old children. Furthermore, results revealed a strong significant correlation between the four Random Gap Detection Test subtests. There was a modest correlation between the Random Gap Detection Test results and the dichotic listening tests. No significant correlation was observed between the Random Gap Detection Test data and the results of the other tests in the battery.

Conclusion

Random Gap Detection Test should not be administered to children younger than 7 years old because other reduced capacities might influence their performance. Also, Random Gap Detection Test assesses a specific auditory ability, different than the one evaluated with the other auditory tests. Finally, it is suggested to test individuals at only one frequency of the Random Gap Detection Test because results provide similar information than when assessing them on all subtests.