40 research outputs found

    Sensitivity and specificity of auditory steady‐state response testing

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    INTRODUCTION: The ASSR test is an electrophysiological test that evaluates, among other aspects, neural synchrony, based on the frequency or amplitude modulation of tones. OBJECTIVE: The aim of this study was to determine the sensitivity and specificity of auditory steady-state response testing in detecting lesions and dysfunctions of the central auditory nervous system. METHODS: Seventy volunteers were divided into three groups: those with normal hearing; those with mesial temporal sclerosis; and those with central auditory processing disorder. All subjects underwent auditory steady-state response testing of both ears at 500 Hz and 2000 Hz (frequency modulation, 46 Hz). The difference between auditory steady-state response-estimated thresholds and behavioral thresholds (audiometric evaluation) was calculated. RESULTS: Estimated thresholds were significantly higher in the mesial temporal sclerosis group than in the normal and central auditory processing disorder groups. In addition, the difference between auditory steady-state response-estimated and behavioral thresholds was greatest in the mesial temporal sclerosis group when compared to the normal group than in the central auditory processing disorder group compared to the normal group. DISCUSSION: Research focusing on central auditory nervous system (CANS) lesions has shown that individuals with CANS lesions present a greater difference between ASSR-estimated thresholds and actual behavioral thresholds; ASSR-estimated thresholds being significantly worse than behavioral thresholds in subjects with CANS insults. This is most likely because the disorder prevents the transmission of the sound stimulus from being in phase with the received stimulus, resulting in asynchronous transmitter release. Another possible cause of the greater difference between the ASSR-estimated thresholds and the behavioral thresholds is impaired temporal resolution. CONCLUSIONS: The overall sensitivity of auditory steady-state response testing was lower than its overall specificity. Although the overall specificity was high, it was lower in the central auditory processing disorder group than in the mesial temporal sclerosis group. Overall sensitivity was also lower in the central auditory processing disorder group than in the mesial temporal sclerosis group.Coordenação e Aperfeiçoamento de Pessoal de Nivel Superior (CAPES

    Teste de fala comprimida em português

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    INTRODUCTION: The time-compressed speech test has existed since the 1970s. It is sensitive for evaluating auditory closure. However, it is not used in Brazil because until recently, it had not been developed in Portuguese. PURPOSE: To develop a compressed speech test in Portuguese, to apply it to normal-hearing adults, and to verify which of the compressed lists (50%, 60%, or 70%) is the most appropriate to be part of a set of auditory processing tests. METHODS: 144 normal-hearing adults, distributed homogeneously between both genders, were assessed. The compressed speech tests were applied using monosyllables and disyllables according to 8 previously established sequences, and the results were compared with respect to the initial ear, to the order of presentation, and to the kind of test. RESULTS: There were no significant differences between ears. The 50%, 60% and 70% presentation order produced a better average of correct responses than the 70%, 60% and 50% one. There was a significant difference (PINTRODUÇÃO: O teste de fala comprimida existe há mais de 30 anos, é sensível para avaliar o fechamento auditivo, porém não é usado no Brasil, já que, até os dias de hoje, ainda não havia sido desenvolvido para o português do Brasil. OBJETIVOS: Elaborar um teste de fala comprimida em português e aplicá-lo em adultos normo-ouvintes, verificar qual das listas comprimidas (50, 60 e 70%) é a mais apropriada para integrar o grupo de testes de Processamento Auditivo. MÉTODOS: Foram avaliados 144 indivíduos adultos, distribuídos homogeneamente entre os gêneros masculino e feminino. Foram aplicados os testes de fala comprimida com monossílabos e dissílabos, de acordo com oito seqüências previamente estabelecidas para em seguida comparar os resultados de acordo com a orelha inicial, ordem de apresentação e tipo de teste. RESULTADOS: Não houve diferença estatisticamente significante entre as orelhas, a ordem crescente de apresentação mostrou uma média de acertos melhor que a decrescente, os testes com monossílabos apresentaram maior média de acertos que os dissílabos e em ambos os testes (com monossílabos e com dissílabos) a média de acertos diminui com o aumento da compressão. CONCLUSÃO: As listas de monossílabos e dissílabos com compressão de 60% mostraram-se mais estáveis que as outras, com média de acerto em torno de 90%

    Temporal resolution in individuals with neurological disorders

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    OBJECTIVE:Temporal processing refers to the ability of the central auditory nervous system to encode and detect subtle changes in acoustic signals. This study aims to investigate the temporal resolution ability of individuals with mesial temporal sclerosis and to determine the sensitivity and specificity of the gaps-in-noise test in identifying this type of lesion.METHOD:This prospective study investigated differences in temporal resolution between 30 individuals with normal hearing and without neurological lesions (G1) and 16 individuals with both normal hearing and mesial temporal sclerosis (G2). Test performances were compared, and the sensitivity and specificity were calculated.RESULTS:There was no difference in gap detection thresholds between the two groups, although G1 revealed better average thresholds than G2 did. The sensitivity and specificity of the gaps-in-noise test for neurological lesions were 68% and 98%, respectively.CONCLUSIONS:Temporal resolution ability is compromised in individuals with neurological lesions caused by mesial temporal sclerosis. The gaps-in-noise test was shown to be a sensitive and specific measure of central auditory dysfunction in these patients

    Development and analysis of a low-cost screening tool to identify and classify hearing loss in children: a proposal for developing countries

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    OBJECTIVE: A lack of attention has been given to hearing health in primary care in developing countries. A strategy involving low-cost screening tools may fill the current gap in hearing health care provided to children. Therefore, it is necessary to establish and adopt lower-cost procedures that are accessible to underserved areas that lack other physical or human resources that would enable the identification of groups at risk for hearing loss. The aim of this study was to develop and analyze the efficacy of a low-cost screening tool to identify and classify hearing loss in children. METHODS: A total of 214 2-to-10 year-old children participated in this study. The study was conducted by providing a questionnaire to the parents and comparing the answers with the results of a complete audiological assessment. Receiver operating characteristic (ROC) curves were constructed, and discriminant analysis techniques were used to classify each child based on the total score. RESULTS: We found conductive hearing loss in 39.3% of children, sensorineural hearing loss in 7.4% and normal hearing in 53.3%. The discriminant analysis technique provided the following classification rule for the total score on the questionnaire: 0 to 4 points - normal hearing; 5 to 7 points - conductive hearing loss; over 7 points - sensorineural hearing loss. CONCLUSION: Our results suggest that the questionnaire could be used as a screening tool to classify children with normal hearing or hearing loss and according to the type of hearing loss based on the total questionnaire scor

    Association between language and hearing disorders – risk identification

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    OBJECTIVE: To identify children at risk for hearing and/or language disorders and to investigate the association between these risks by conducting pre-validated hearing and language screenings. METHODS: The study was conducted during a polio vaccination campaign in August of 2013 in basic health units in western São Paulo. Parents of children between 2 and 5 years of age were asked to complete two screening tools: a hearing questionnaire (regarding hearing development) and a language production and comprehension scale (including the major language development milestones). The screening tools were administered by different researchers. We compared the risk of having language disorders among children at risk for hearing loss versus children not at risk, as well as the attributable risk and odds ratios. Chi-squared tests and logistic regression analyses were used. RESULTS: The study included 479 children with a mean age of three and one-half years, of whom 26.9% were identified as at risk for deficits in language production, 8.6% were at risk for deficits in language comprehension and 14% were at risk for hearing disorders. The children at risk for hearing disorders were twice as likely as those not at risk to exhibit language production and comprehension deficits. CONCLUSION: The results of this study highlight the importance of establishing and adopting low-cost procedures such as screenings to identify children at risk of developing language and/or hearing disorders in early childhood

    P300 in workers exposed to occupational noise

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    The harm upon the central auditory pathways of workers exposed to occupational noise has been scarcely studied. Objective: To assess the central auditory pathways by testing the long latency auditory evoked potentials (P300) of individuals exposed to occupational noise and controls. Method: This prospective study enrolled 25 individuals with normal hearing thresholds. The subjects were divided into two groups: individuals exposed to occupational noise (13 subjects; case group) and individuals not exposed to occupational noise (12 subjects; control group). The P300 test was used with verbal and non-verbal stimuli. Results: No statistically significant differences were found between ears for any of the stimuli or between groups. The groups had no statistically significant difference for verbal or non-verbal stimuli. Case group subjects had longer latencies than controls. In qualitative analysis, a greater number of altered P300 test results for verbal and non-verbal stimuli was seen in the case group, despite the absence of statistically significant differences between case and control subjects. Conclusion: Individuals exposed to high sound pressure levels had longer P300 latencies in verbal and non-verbal stimuli when compared to controls

    ELSA-Brasil: a 4-year incidence of hearing loss in adults with and without hypertension

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    OBJECTIVE To compare the incidence of hearing loss among adults stratified by the occurrence of hypertension, and to investigate the association between hypertension and hearing loss. METHODS Longitudinal observational study, part of the Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil, Longitudinal Study on Adult’s Health). Data from the first and second waves were analyzed, including information from audiological assessment and general health of the subjects. As outcome, we considered the presence of hearing loss (hearing thresholds above 25 dBHL at frequencies from 500 Hz to 8 kHz) and, as exposure variable, hypertension (report of medical diagnosis of hypertension; and/or use of drugs to treat hypertension; and/or pressure systolic blood pressure ≥ 140 mmHg; or diastolic blood pressure ≥ 90 mmHg). As covariables for adjustment were considered: sex, age, education, race / ethnicity, income, smoking, diabetes, and occupational exposure to noise. Poisson regression analysis was conducted, estimating the crude and adjusted relative risks, with 95% confidence intervals, in order to assess the factors associated with hearing loss. RESULTS In crude analyses, the incidence of hearing loss was higher for subjects with hypertension (9.7% versus 5.4%). The crude relative risks for hearing loss was almost double (1.93; 95%CI: 1.10–3.39) for subjects with hypertension in the right ear. In the adjusted analyses, the relative risks was not significant for the hypertension variable (1.42; 95%CI: 0.75–2.67). Being 60 years or older (RR: 5.41; 95%CI: 2.79–10.50) showed a statistically significant association with hearing loss, indicating that older adults have higher relative risks for hearing loss. CONCLUSION In the adjusted analyses controlled for multiple risk factors there was no association between hypertension and hearing loss. The dichotomous variable age (being 60 years or older), on the other hand, has shown a significant association with hearing loss

    Avaliação das funções cognitivas em idosos com e sem alterações no processamento auditivo central

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    RESUMO Objetivo Avaliar e comparar as funções cognitivas entre idosos com e sem alteração do processamento auditivo central. Método Vinte e oito idosos saudáveis (14 do grupo controle e 14 do grupo Transtorno do Processamento Auditivo Central - TPAC) participaram do estudo. Todos os idosos foram submetidos à bateria mínima de avaliação do processamento auditivo central (PAC), ao potencial auditivo cognitivo P300 e a bateria cognitiva breve (BCB). Na comparação entre sujeitos, foi aplicado o teste de Mann-Whitney e na comparação intra-sujeitos, utilizamos o teste de postos sinalizados de Wilcoxon. Para verificar se houve associação entre o desempenho do PAC e das variáveis cognitivas, foi utilizada a correlação de Spearman. Resultados Não houve diferenças estatisticamente significantes entre os grupos ‘Controle’ e TPAC para a maioria das habilidades cognitivas avaliadas por meio da BCB, bem como para as variáveis do potencial cognitivo P300. Contudo, houve diferença estatisticamente significante entre o desempenho do grupo ‘Controle’ e TPAC para a prova do desenho do relógio. Além disso, foi possível observar correlação entre o desempenho do teste do relógio e no TPF. Conclusão Idosos com TPAC não apresentaram alteração na maior parte dos testes cognitivos, com exceção da prova do desenho do relógio, cuja tarefa envolve múltiplas funções cognitivas, incluindo processamento visuoespacial, função executiva, memória semântica e planejamento

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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