Limiar Diferencial de mascaramento e potencial evocado auditivo de tronco encefálico em adultos normo-ouvintes com zumbido / Masking Level Difference and Auditory Brainstem ResponseIn Normal Hearing Adults With Tinnitus / Umbral de enmascaramiento diferencial y potencial evocado auditivo del tronco encefálico en adultos con audición normal y tinnitus

Introdução: O zumbido é uma ilusão auditiva consciente, uma sensação sonora não relacionada com uma fonte externa de estimulação. Objetivos: Caracterizar a Acufenometria, Limiar Diferencial de Mascaramento, o questionário de qualidade de vida Inventário de Desvantagem do Zumbido e Potencial Auditivo de Tronco Encefálico em adultos normo-ouvintes com zumbido, com a finalidade de comparar seus achados. Método: Vinte indivíduos do sexo feminino e masculino, entre 20 e 60 anos de idade, normo-ouvintes com queixa de zumbido, foram submetidos ao Acufenometria, Limiar Diferencial de Mascaramento, Inventário de Desvantagem do Zumbido e Potencial Evocado Auditivo de Tronco Encefálico. Resultados: AAcufenometriarevelou que o pitch médio foi de 4,3 KHz à orelha direita e 4,6 KHz à orelha esquerda. O loudness médio foi de 21,7 dBNS à orelha direita e 23,5 dBNS à orelha esquerda. O Limiar Diferencial de Mascaramento médio mostrou-se alterado. O Inventário de Desvantagem do Zumbido médio correspondeu à classificação de grau leve. O Potencial Evocado Auditivo de Tronco Encefálico apresentou parâmetros dentro da normalidade bilateralmente. Conclusão: Constatou-se que adultos normo-ouvintes com queixa de zumbido apresentam zumbido de pitch agudo bilateral com discreto impacto na qualidade de vida, condução adequada das vias auditivas até o tronco encefálico e comprometimento na identificação de sons na presença de ruído, demonstrando que o zumbido pode ter repercussões nas habilidades auditivas centrais. (AU)

Introduction: Tinnitus is a conscious auditory illusion, a sound perception unrelated to any external stimulus source. Objectives: To characterize the Acuphenometry, Masking Level Difference, the quality of life questionnaire Tinnitus Handicap Inventory and Auditory Brainstem Response in normal hearing adults with tinnitus, with the purpose of comparing the findings. Method: Twenty female and male individuals, between 20 and 60 years of age, normal hearing with complaints of tinnitus, underwent Acuphenometry, Masking Level Difference, Tinnitus Handicap Inventory and Auditory Brainstem Response. Results: The Acuphenometry showed the average pitch was 4.3 KHz to the right ear and 4.6 KHz to the left ear. The average loudness was 21.7 dBSL to the right ear and 23.5 dBs to the left ear. The average Masking Level Difference was altered. The average Tinnitus Handicap Inventory corresponded to the classification of mild grade. Auditory Brainstem Response showed parameters within normal range bilaterally. Conclusion: It was found that normal hearing adults with tinnitus complaints have bilateral acute pitch tinnitus with a slight impact on quality of life, appropriate conduction of auditory pathways to the brainstem and impaired identification of sounds in the presence of noise, demonstrating that tinnitus can have repercussions on central auditory skills. (AU)

Introducción: El tinnitus es una ilusión auditiva consciente, una sensación de sonido no relacionada con una fuente externa de estimulación. Objetivos: Caracterizar la coincidencia de tono y volumen, el umbral de enmascaramiento diferencial, el inventario de minusvalía para acúfenos y el potencial auditivo del tronco encefálico en adultos normoyentes con acúfenos, con el fin de comparar sus hallazgos. Método:Veinte sujetos masculinos y femeninos, con edades entre 20 y 60 años, audición normal con tinnitus, fueron sometidos a acúfenos, Umbral de Enmascaramiento Diferencial, Inventario de Desventajas de Tinnitus y Potenciales Evocados Auditivos del Tronco Encefalico. Resultados: La combinación de tono y volumen reveló que el tono promedio era de 4,3 KHz en el oído derecho y de 4,6 KHz en el oído izquierdo. Mientras que el volumen medio fue de 21,7 dBNS para el oído derecho y de 23,5 dBNS para el oído izquierdo. Se modificó el umbral diferencial de enmascaramiento promedio. El Inventario de Desventajas de Tinnitus promedio correspondió a la clasificación de grado leve. El Potenciales Evocados Auditivos del Tronco Encefalico presentó parámetros dentro del rango normal bilateralmente. Conclusión:Se encontró que los adultos normooyentes con quejas de tinnitus presentan tinnitus de tono alto bilateral con leve impacto en la calidad de vida, conducción adecuada de las vías auditivas al tronco encefálico y deterioro en la identificación de sonidos en presencia de ruido, demostrando que Tinnitus puede tener repercusiones en las habilidades auditivas centrales. (AU)

O uso do mascaramento contralateral na pesquisa do potencial evocado auditivo de tronco encefálico por condução aérea: revisão sistemática / Use of contralateral masking in air-conduction auditory brainstem response: systematic review

RESUMO Objetivos analisar criticamente a necessidade do uso do mascaramento contralateral na pesquisa do potencial evocado auditivo de tronco encefálico (PEATE) por condução aérea, na perda auditiva sensorioneural unilateral ou bilateral assimétrica, por meio de uma revisão sistemática da literatura. Estratégia de pesquisa foram consultadas as bases de dados eletrônicas PubMed/MEDLINE, LILACS, ADOLEC, IBECS, SciELO, Web of Science, Scopus e Embase, bem como os anais do Encontro Internacional de Audiologia e do Congresso Brasileiro de Fonoaudiologia, além das bases de instituições com pós-graduação em Fonoaudiologia, utilizando os descritores Evoked Potentials, Auditory, Brain Stem, Perceptual Masking e Hearing Loss, Sensorineural. Critérios de seleção foram selecionados os estudos com níveis de evidência de 1 a 5, publicados em português, inglês ou espanhol, até janeiro de 2018. Os artigos deveriam abordar a necessidade do uso do mascaramento contralateral na pesquisa do PEATE por condução aérea, em indivíduos com perda auditiva sensorioneural unilateral ou bilateral assimétrica. Resultados foram encontrados 334 estudos, sendo que oito artigos contemplaram os critérios preestabelecidos. Os estudos incluídos foram controversos quanto ao uso do mascaramento contralateral. Conclusão não existe um consenso quanto à necessidade do uso do mascaramento contralateral no PEATE por condução aérea, em indivíduos com perda auditiva sensorioneural unilateral. No entanto, a maioria dos estudos direcionou para a sua utilização na pesquisa do PEATE com estímulo clique em indivíduos com perda auditiva sensorioneural unilateral de graus severo e profundo.

ABSTRACT Purpose Critically analyze the need to use contralateral masking in the measurement of Auditory Brainstem Response (ABR) by air conduction on unilateral or bilateral asymmetric sensorineural hearing loss by means of a systematic literature review. Research strategies A search was conducted at the PubMed/MEDLINE, LILACS, ADOLEC, IBECS, SciELO, Web of Science, Scopus and Embase electronic databases, proceedings of the International Meeting of Audiology and the Brazilian Congress of Speech-language Pathology and Audiology, and bases of institutions with Graduate Studies Programs in Speech-language Pathology and Audiology, using the following descriptors: Evoked Potentials, Auditory, Brainstem, Perceptual Masking, Hearing Loss, and Sensorineural. Selection criteria Studies with levels of evidence from 1 to 5 published in Portuguese, English or Spanish until January 2018 were selected. The articles should address the need to use contralateral masking in the measurement of air-conduction ABR in individuals with unilateral or bilateral asymmetric sensorineural hearing loss. Results A total of 334 studies were found, and eight of them met the pre-established criteria. The studies included in the review were controversial as to the need for contralateral masking. Conclusion There is no consensus on the need to use contralateral masking in the measurement of ABR by air conduction in individuals with unilateral sensorineural hearing loss; however, most studies report the use of contralateral masking in the measurement of ABR with click stimulus in individuals with severe and profound unilateral sensorineural hearing loss.

Efeito da idade no processamento auditivo temporal: benefício da modulação do mascaramento e efeito do pós-mascaramento / Age effects in temporal auditory processing: modulation masking release and forward masking effect

RESUMO Objetivo Investigar o efeito da idade no benefício da modulação do ruído mascarante (masking release) e no pós-mascaramento ( forward masking). Métodos Participaram da pesquisa jovens (média de idade de 18 anos e quatro meses) e idosos (média de idade de 64 anos e três meses) falantes nativos do Português Brasileiro e com audição normal. Mediante uso de sentenças da versão brasileira do Hearing in Noise Test, determinou-se, para ambos os grupos, limiares de reconhecimento em presença de ruído estável e em presença de ruído modulado em amplitude (10 Hz). Para a pesquisa do pós-macaramento, foram determinados limiares auditivos em intervalos de tempo de 4, 16, 64 e 128 milissegundos, após a interrupção do ruído. Para avaliar a normalidade dos resultados obtidos, foi aplicado o teste de Shapiro-Wilk. Nas variáveis em que a normalidade foi indicada, aplicou-se o teste t de Student para amostras independentes e nos casos em que a normalidade não foi encontrada, aplicou-se o teste de Mann-Whitney. Foi considerado o nível de significância de 5% Resultados Observou-se o benefício da modulação do mascaramento nos dois grupos. Porém, esse benefício foi menor para o grupo dos idosos (p-valor < 0,001). Na investigação do pós-mascaramento, houve diferença significativa entre os grupos, na média de limiares em 128 milissegundos, após a cessação do ruído (p-valor = 0,006). Conclusão O estudo mostra efeito da idade no benefício de modulação do ruído mascarante e no pós-mascaramento.

ABSTRACT Purpose The purpose of this study was to investigate the age-related effects of modulation masking release and forward masking. Methods Ten younger (mean age of 18.4) and ten older (mean age of 64.3) adults participated in the study. All participants were native speakers of Brazilian Portuguese with normal hearing. Sentences of the Brazilian version of the Hearing in Noise Test were used to obtain speech recognition thresholds in the presence of steady-state noise and amplitude-modulated noise (10 Hz). To investigate forward masking, auditory thresholds were determined at time intervals of 4, 16, 64, and 128 ms after noise interruption. The Shapiro-Wilk test was applied to evaluate the normality of the results. In the variables in which normality was indicated, the Student's t-test was applied for the independent samples, and the Mann-Whitney test was applied in cases where normality was not found. A significance level of 5% was adopted for all statistical analyses. Results Modulation masking release was present in both groups; however, it was significantly smaller in the elderly group. As for forward masking investigation, higher thresholds were obtained after noise interruption, and improved as the time interval between noise and stimulus presentation increased. Forward masking was higher in the elderly group, whit higher thresholds for the time interval of 128 ms. Conclusion An age-related effect was identified on modulation masking release and forward masking.

Masking Level Difference em escolares: análises ambientais / Masking Level Difference in schoolchildren: environmental analysis

RESUMO Objetivo Pesquisar a habilidade auditiva de atenção seletiva na população escolar e identificar valores de referência para a faixa etária de sete a dez anos por meio do teste Masking Level Difference, além de identificar se a escolaridade dos pais, bem como a renda familiar, pode influenciar os resultados do teste. Método Participaram do estudo 31 escolares que se encaixaram nos critérios de elegibilidade da pesquisa, sendo 20 do gênero feminino e 11 do gênero masculino. Realizou-se anamnese para questionamento da renda familiar e escolaridade dos pais do escolar, inspeção visual do meato acústico externo, audiometria tonal liminar, logoaudiometria, medidas de imitância acústica, teste Dicótico de Dígitos e teste Masking Level Difference. Resultados A idade média dos indivíduos foi de 8,67 anos. Não foi observada diferença entre os gêneros e entre as idades avaliadas, no desempenho do MLD. Não houve relação entre a escolaridade dos pais e a renda mensal média com o desempenho das crianças no MLD. A média do MLD foi de 7,65 dB, com desvio padrão de 2,51 dB. Conclusão O Masking Level Difference em escolares de sete a dez anos é de 7,65 dB e independe do gênero, do nível de escolaridade dos pais ou da renda mensal média da família do escolar.

ABSTRACT Purpose To investigate the auditory ability of selective attention in the school population and to identify reference values to the age group from seven to ten years old through the Masking Level Difference Test, and to identify if the parents' schooling, as well as the family income can influence the test results. Methods Thirty-one schoolchildren who match the eligibility criteria attended the study, being 20 female and 11 male. An anamnesis was conducted to question the familiar income and the schooling of the children´s parents; we also performed visual inspection of the External Acoustic Meatus, Pure Tone Audiometry, Speech Audiometry, Acoustic Immittance Measures, Dichotic Digits Test and Masking Level Difference test. Results The mean age of the individuals was 8.67 years. There were no observed differences between genders and between the evaluated ages in the MLD performance. There was no relation between the parents' schooling and the average monthly income with the performance of the children in MLD Test. The MLD mean was 7.65 dB and standard deviation of 2.51 dB. Conclusion The Masking Level Difference in schoolchildren from seven to ten years old is 7.65 dB and is independent of the gender, parents' schooling and the average monthly income of the schoolchild.

Enmascaramiento clínico: una revisión de la literatura / Clinical masking: a literature review

Son diversos los métodos planteados para aplicar enmascaramiento, de esta forma es necesario revisar la literatura en búsqueda de consenso. Se revisaron críticamente los métodos utilizados y recomendados por la literatura y sociedades internacionales, en torno a la aplicación de enmascaramiento. Se consultó entre agosto y noviembre de 2015 en PUBMED, SciELO y Google Scholar por estudios acerca de métodos de enmascaramiento utilizados en audiometría. También se revisaron las guías de organizaciones internacionales y lo publicado en libros relacionados con el área de audiología. El método de "La Meseta" es el más referenciado, siendo modificado posteriormente. Existen variaciones en criterios de atenuación interaural, necesidad de enmascaramiento, enmascaramiento inicial, incrementos para obtener la meseta y niveles del efecto de oclusión. Se concluye que la literatura muestra diferencias al momento de decidir cuándo enmascarar y cómo hacerlo. No obstante, se puede establecer criterios comunes en relación a los niveles de atenuación interaural, cuándo enmascarar, valores de efecto de oclusión y metodología. El método de "La Meseta" sigue siendo el más recomendado. La modificación realizada por Yacullo es la más referenciada y recomendada en la literatura actual.

Adequate use of masking is key in the correct diagnosis of hearing loss. Various methods are suggested regarding the application of clinical masking, hence the need to review literature in order to reach a consensus. To critically review the specialized literature and international societies' recommendations regarding clinical masking. From August to November 2015, PUBMED, SciELO and Google Scholar articles on clinical masking methods used in tonal audiometries were consulted, as well as international organization guidelines, and literature in the area of Audiology. Hood's plateau method, later revised, received the most references. The modified versions consider the number of increments needed to determine the true threshold, and the occlusion effect. Optimized methods show the variations regarding interaural attenuation, need for masking, initial masking level, increments to reach "The Plateau", and the occlusion effect. Literature shows differences regarding when and how to use masking; however, common criteria can be established with reference to the levels of interaural attenuation, when to use masking, occlusion effect values and methodology. The plateau method proposed by Hood is still the most recommended. Yacullo's optimization is currently the one with the most references and recommendations in specialized literature.

Programa de treinamento auditivo em portadores de zumbido / Auditory training program in subjects with tinnitus

RESUMO O zumbido pode ser definido como a percepção consciente de um som, sem a presença de estimulação acústica externa. Considerando o prejuízo causado pelo zumbido e a falta de tratamentos definitivos, fica evidente a necessidade de alternativas para reabilitação de pessoas com zumbido. A hipótese é que o treinamento auditivo pode causar uma reorganização plástica desse sistema, promovendo uma melhora do sintoma. Objetivo: Verificar o efeito de um programa de treinamento auditivo em portadores de zumbido na percepção desse sintoma. Métodos: Participaram 12 indivíduos portadores de zumbido, divididos em dois grupos: Grupo Estudo (GE) e Grupo Controle (GC). Todos os indivíduos realizaram: audiometria; avaliação eletrofisiológica; acufenometria; aplicação do Tinnitus Handicap Inventory (THI) e avaliação do processamento auditivo (GIN - Gaps In Noise , Teste de Padrão de Frequência e Fala com Ruído). Após a avaliação, foram iniciados os treinamentos e o GE foi submetido ao treinamento auditivo formal enquanto o GC ao treinamento visual. Resultados: Na caracterização dos grupos não foram observadas diferenças estatisticamente significantes para as variáveis: idade, pitch e loudness do zumbido, nem para os limiares auditivos na audiometria convencional e altas frequências. Na comparação entre os grupos, pré e pós-treinamento, dos testes eletrofisiológicos, comportamentais e THI não houve diferenças estatisticamente significantes entre eles para nenhuma das avaliações realizadas. Conclusão: Achados não mostraram diferenças estatisticamente significantes entre os grupos na comparação entre pré e pós-treinamento (auditivo ou visual), tanto para os achados eletrofisiológicos quanto para a avaliação comportamental do processamento auditivo e para o THI, embora diferenças pontuais na análise individual tenham ocorrido.

ABSTRACT Tinnitus may be defined as the conscious perception of sound or noise, without the presence of external acoustic stimulation. Given the damage caused by tinnitus and the lack of effective treatment, alternatives are necessary to rehabilitate subjects with tinnitus. There is an assumption that auditory training (AT) could lead to a plastic reorganization of this system, thus promoting an improvement of the symptom. Objective: To verify the effect of an AT program in subjects with tinnitus in the perception of this symptom. Methods: Twelve subjects with tinnitus were included in the study and divided into two groups: Study Group (SG) and Control Group (CG). All of them underwent audiometric and electrophysiological assessments; acuphenometry; Tinnitus Handicap Inventory and auditory processing assessment (GIN - Gaps in Noise, Frequency Pattern Test and Speech-in-Noise). Afterward, trainings began and the SG was submitted to the formal AT, and the CG to the visual training. Results: In the characterization of the groups, no statistically significant difference was found for the variables such as age, pitch, and loudness of tinnitus, or for hearing thresholds in conventional audiometry and high frequencies. Comparisons were performed between the groups, before and after the trainings, regarding electrophysiological, behavioral, and Tinnitus Handicap Inventory tests, and no statistically significant differences were found between them for any of the evaluations. Conclusion: Findings showed no statistically significant differences between groups in the comparison between the moments pre- and post-trainings (auditory or visual), nor for the electrophysiological findings or behavioral assessment of the auditory processing and for the Tinnitus Handicap Inventory, although some specific differences in the individual analysis have occurred.

The study of acoustically evoked short latency negative responses in normal guinea pigs / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To compare acoustically evoked short latency negative responses (ASNR) elicited from normal and profound hearing loss guinea pig ears and to confirm their vestibular nuclei origination.</p><p><b>METHODS</b>Forty healthy guinea pigs were employed in the experiment, which were randomly divided into the control group (8 subjects, 16 ears), the masking group (16 subjects, 32 ears) and the deafened group (16 subjects, 32 ears). Air conductive white noise was chosen for masking. Masking dilemma was avoidable by an appropriate 15 dB gap between stimulus and masking sound. Both the masking group and the deafened group were further divided into ASNR group and non-ASNR group based on the presence of ASNR. Electrolytic lesion was conducted to the vestibular nuclei, followed by ABR/ASNR recording. The lesioned brainstem slices were microscopically verified.</p><p><b>RESULTS</b>In the masking group, ASNR were present in 24 ears (75.0%, 24/32) and 12 ears (46.2%, 12/26) in deafened group, showing statistically higher presence rate for masking group (χ(2)=5.07, P=0.024). There were no significant differences for the ASNR threshold and latency between the masking ASNR group and the deafened ASNR group. For the two ASNR groups, electrolytic destruction to the vestibular nuclei subsequently eliminated the ASNR. Brainstem slice proved the accurate sites of electrolytic lesion.</p><p><b>CONCLUSION</b>Moderate white noise masking prevents hearing system potential overlap without affecting vestibular system, therefore, ASNR is successfully elicited in normal guinea pigs. Both ASNRs from normal and deafened guinea pigs are of similar natures and origination from, the vestibular nuclei.</p>

A new paradigm for temporal masking assessment: pilot study / Um novo paradigma para a avaliação do mascaramento temporal auditivo: estudo piloto

PURPOSE: To determine the feasibility and applicability of a clinical backward masking test, focusing on the analysis of inter-stimuli interval, and not on the intensity thresholds as it has been traditionally done, thus proposing a new paradigm for temporal masking assessment. METHOD: The test consisted of the presentation of a target tone of 1.000 Hz followed by a broadband masking noise (950-1.050 Hz), with inter-stimuli interval of 0, 10, 20, 50 and 100 ms. The stimuli were presented monaurally to both ears, with intensity ratio between masker and target tone varying between -10, -20, -30 and -40 dB. Twenty undergraduate students, without hearing or auditory processing complaints, participated in this study. RESULTS: Regardless of the signal-to-noise ratio, we observed decrease of average performance according to the decrease of the interval between stimuli. We also observed the indication that little or no masking occurs at the 100 ms interval, suggesting this interval is unsuitable for temporal masking assessment. The average interval threshold was below 27 ms for all investigated intensities, and increased 9 ms with every increase of 10 dB at signal-to-noise ratio. The signal-to-noise ratios of -20 and -30 were the best ratios for the test application. CONCLUSION: The paradigm proposed in this pilot study proved to be feasible, easy to apply, and trustworthy, being compatible with other researches which are the foundation for the study of temporal masking. This theme deserves further studies, continuing the analysis initiated here. .

OBJETIVO: Determinar a viabilidade e aplicabilidade de um teste clínico do mascaramento temporal sucessor, com foco de análise nos intervalos interestímulos e não nos limiares de intensidade, como tradicionalmente realizado, propondo, assim, um novo paradigma para a avaliação do mascaramento temporal. MÉTODO: O teste contou com a apresentação de um tom alvo de 1.000 Hz seguido de um ruído mascarador de banda estreita (950-1.050 Hz), com intervalos entre os estímulos de 0, 10, 20, 50 e 100 ms. Os itens foram apresentados de forma monoaural em ambas as orelhas, com relação de intensidade entre o mascarador e o tom alvo variando entre -10, -20, -30 e -40 dB. Vinte universitários, sem queixas de audição ou de processamento auditivo, participaram deste estudo. RESULTADOS: Foi observada diminuição no desempenho médio de acordo com a diminuição do intervalo, independentemente da relação sinal-ruído. Observou-se também o indício de que pouco ou nenhum mascaramento ocorre para o intervalo de 100 ms, tornando-o inadequado para a avaliação do mascaramento temporal. O limiar de intervalo médio manteve-se abaixo de 27 ms para todas as intensidades avaliadas, e aumentou 9 ms a cada 10 dB de aumento na relação sinal-ruído. As melhores relações sinal-ruído para avaliação são -20 e -30 dB. CONCLUSÃO: O paradigma proposto neste estudo piloto provou-se factível, de fácil aplicação e confiável, mostrando-se compatível com resultados de pesquisas que fundamentam o estudo do mascaramento temporal. O tema merece outros estudos para aprofundar as análises aqui iniciadas. .

500 Hz masking level difference test for Chinese: a pilot study / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>A pilot study found the masking level difference (MLD) normal value of Chinese aged from 10 to 40, served to clinical practice.</p><p><b>METHOD</b>Seventy-three normal persons with hearing threshold < 20 dB and no disorder of otology were divided into three groups: classified 10-20 age as A group, 21-30 age as B group, 31-40 age as C group. MLD of age, gender and race were determined by the audiometer with dual channel by playing audio test disc. Same tests were compared with English language.</p><p><b>RESULTS</b>The mean value of MLD in Chinese was (11.1 ± 3.4) dB and the 95% normal reference values were between 4.4 to 17.8 dB . There was no difference in term of gender. The value of MLD increased with age. In the term of language, foreign showed high value of MLD than that of Chinese.</p><p><b>CONCLUSIONS</b>The measuring of MLD depends on age and language but not depends on gender. The normal threshold of MLD depends on age and language should be measured when normal values were applied to assess MLD in clinical practice.</p>

Percepção da fala em presença de ruído competitivo: o efeito da taxa de modulação do ruído mascarante / Effect of modulation rate on masking release for speech

OBJETIVO: Este estudo investigou o efeito das diferentes taxas de modulações do mascaramento na magnitude do masking release. MÉTODOS: Quinze indivíduos jovens, com audição normal, foram submetidos ao teste de reconhecimento de sentença na presença de ruído, utilizando as listas de sentenças do HINT-Brasil. Foram obtidos limiares de reconhecimento de fala em presença de ruído estável e ruído modulado, em diferentes taxas de modulação (4, 8, 16, 32 e 64 Hz). A magnitude do masking release foi obtida para cada modulação e foi realizada a análise comparativa dos resultados. RESULTADOS: Os achados demonstraram melhores limiares de reconhecimento de sentenças quando o ruído mascarante foi modulado em 4, 8, 16 e 32 Hz e piores limiares quando o ruído mascarante estava estável e em 64 Hz. No que diz respeito à análise da relação sinal/ruído, foram observados, no presente estudo, maiores valores para as tarefas que envolvem reconhecimento de sentenças com ruído estável, seguidos das tarefas que envolvem reconhecimento de sentenças com ruído modulado em 64 Hz, e menores valores para as tarefas que envolvem reconhecimento de sentenças com ruído modulado em 32, 16, 8 e 4 Hz, respectivamente. CONCLUSÃO: A magnitude do masking release para sentenças não se diferencia com taxas de modulação em amplitude entre 4 e 32 Hz. No entanto, quando a taxa de modulação é elevada a 64 Hz, a magnitude do masking release diminui.

PURPOSE: To investigate the effect of modulation rate on masking release for speech. METHODS:Fifteen normal hearing subjects participated in the study. They were tested on speech perception in noise using the sentences of the HINT-Brazil. Speech recognition thresholds were obtained in the presence of steady masking and amplitude modulated masking at rates of 4, 8, 16, 32 and 64 Hz. The magnitude of masking release was obtained for each modulation rate, and results were compared. RESULTS:Data showed significantly lower speech thresholds when the masking noise was amplitude modulated at rates of 4, 8, 16 and 32 Hz, when compared to thresholds obtained in steady noise or noise modulated at 64 Hz. Speech-to-masker ratios (SMR) were higher in steady masking noise, followed by modulated noise at 64 Hz, and lower for modulated rates of 32, 16, 8 and 4 Hz, respectively. CONCLUSION: The magnitude of masking release for speech does not seem to differ significantly among modulation rates of 4 to 32 Hz. However, for a modulation rate of 64 Hz the magnitude of masking release is significantly reduced.

A method of synthesizing cicada sound for treatment of tinnitus / 生物医学工程学杂志

Masking therapy can make patients accustom to tinnitus. This therapy is safe and easy to implement, so that it has become a widely used treatment of curing tinnitus. According to surveys of tinnitus sounds, cicada sound is one of the most usual tinnituses. Meanwhile, we have not hitherto found published papers concerning how to synthesize cicada sound and to use it to ameliorate tinnitus. Inspired by the human acoustics theory, we proposed a method to synthesize medical masking sound and to realize the diversity by illustrating the process of synthesizing various cicada sounds. In addition, energy attenuation problem in spectrum shifting process has been successfully solved. Simulation results indicated that the proposed method achieved decent results and would have practical value for the future applications.

The long-term rehabilitation effects for treating tinnitus by tinnitus masking combined with counseling / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the long-term rehabilitation effects for treating tinnitus by tinnitus masking combined with counseling.@*METHOD@#Complete the tinnitus handicap inventory(THI) for participants before treatment and after six months, 1 year, 2 years, 3 years.@*RESULT@#Eighty-six tinnitus patients participated. Nine participants and sixteen, twenty-six, sixteen participants drop-up during the follow up after half-year, 1 year, 2 years, 3 years separately. The percentage of participants whose THI score decreased more than or equal to 20 are 66%, 56%, 40%, 48% after half year, 1 year, 2 years, 3 years respectively.@*CONCLUSION@#The tinnitus related handicap improved by tinnitus masking combined with counseling after 1 year. The drop-out rate was increase after follow-up 1 year. The long-term rehabilitation effects for tinnitus treatment is still needed.

Reduzir-se a nada: articulações entre o masoquismo, o feminino e a máscara / Diminishing to nothing: relations between the masochism, the feminine and the mask / Réduire à néant: les liens entre le masochisme, le féminin et le masque / Reducirse a nada: articulaciones entre el masoquismo, el femenino y la máscara

O artigo demonstra que o feminino não possui uma característica masoquista que lhe seja inerente. O suposto masoquismo feminino seria uma das máscaras utilizadas pelo feminino tanto para localizar-se como mulher como para atrair o desejo de um homem. Concluímos, porém, que existem parcerias tão devastadoras que podem reduzir o sujeito a nada.

This paper demonstrates that the feminine doesn’t have an inherent masochist character. The supposed feminine masochism would be one of the masks used by the feminine as means to find a place as well as to attract the male’s desire. Yet we conclude that there are some partnerships so devastating that they can diminish the subject to nothing.

La présente recherche a comme but démontrer que le féminin ne possède pas une caractéristique masochiste même, naturelle. La recherche nous a permis déduire que le masochisme féminin peut être l’une des masques utilisées par le féminin, soit pour attirer le désir d’ um homme soit pour se situer comme femme. Nous soulevons alors l’hypothèse où les personnages ont établi des partenariatstellements ravageurs qu’elles ont fini pour s’aniquiler en se réduisant au néant.

El artículo demuestra que la mujer no tiene un rasgo masoquista que le es inherente. El supuesto masoquismo femenino sería una de las máscaras usadas tanto para ella localizarse como mujer como para atraer el deseo de un hombre. Llegamos a la conclusión, sin embargo, de que hay asociaciones tan devastadoras que pueden reducir el sujeto a nada.

Efecto de supresión eferente de las emisiones otoacústicas transientes y discriminación de habla en ruido / Efferent suppression of transient-evoked otoacoustic emissions and speech discrimination in noise

El tracto olivo-coclear medial ha sido ampliamente estudiado en animales de experimentación y clínicamente en humanos. Se ha sugerido que una de sus funciones se relaciona con la discriminación del habla en presencia de ruido de fondo. Actualmente no se cuenta con estudios sistemáticos de las posibles correlaciones entre el efecto de supresión eferente y el rendimiento en tareas de discriminación de habla en ruido. Por lo anterior, en nuestro laboratorio estamos investigando los valores del efecto de supresión y cómo estos pueden relacionarse con tareas de discriminación del habla. En el presente artículo se reportan los resultados de un estudio piloto en esta materia. Un grupo de 45 sujetos adultos y auditivamente normales fueron estudiados. Los procedimientos incluyeron emisiones otoacústicas transientes, efecto de supresión de las emisiones otoacústicas transientes, reflejos acústicos ipsi y contralaterales (para las frecuencias 0.5, 1, 2 y 4 KHz) y la prueba de HINT. No se encontraron diferencias estadísticamente significativas para el efecto de supresión eferente entre ambos oídos. Por otra parte, no se observaron correlaciones entre la amplitud del efecto de supresión y los valores obtenidos en la prueba de HINT para las subpruebas de habla en ruido. Se discuten los hallazgos encontrados y la necesidad de futuras investigaciones.

The medial olivo-cochlear bundle has been widely studied in experimental animals and clinically, in human subjects. It has been suggested that one of the functions of this bundle relates to the discrimination of speech in the presence of background noise. No systematic studies of possible associations between the efferent suppression of otoacustic emissions (OAEs) and performance on speech-in-noise tasks has been carried out. For this reason, we are investigating the amplitude of the efferent suppression of OAEs and how this may be associated with performance on speech-in-noise tasks. The results of a pilot study on this topic are addressed in this manuscript. A total of 45 normal-hearing adult subjects were studied. Transient-evoked OAEs (TEOAEs), the efferent suppression of TEOAEs, ipsi and contralateral acoustic reflexes (0.5, 1, 2, and 4 HHz) were obtained and the hearing-in-noise-test (HINT) was administered to all the subjects selected. No significant differences were found in the efferent suppression of TEOAEs between ears. No significant correlations between results for the efferent suppression of TEOAEs and those for the HINT were found. These results and the need for further research are discussed.

Formulation and in vitro evaluation of taste-masked oro-dispersible dosage form of diltiazem hydrochloride

Diltiazem hydrochloride is a calcium channel blocker generally indicated for the treatment of angina and hypertension, and it is extensively metabolized due to the hepatic metabolism. Formulation of diltiazem hydrochloride into an oro-dispersible dosage form can provide fast relief with higher bioavailability. The bitter taste of the drug should be masked to formulate it in a palatable form. In the present work, an attempt was made to mask the taste by complexation technique, with a formulation into an oro-dispersible dosage form, using superdisintegrants Doshion P544, crospovidone (CP) and sodium starch glycolate (SSG). The complexes of diltiazem hydrochloride with β-CD (1:1 molar ratio) were prepared by kneading, co-evaporation, co-grounding, freeze-drying and melting methods. Phase solubility showed stability constant 819.13M-1. Prepared inclusion complexes were evaluated for taste masking and characterized by I.R, XRD, DSC. Using the drug β-CD complex, oro-dispersible tablets were prepared and evaluated for hardness, friability, weight variation, thickness, disintegrating time (DT), dissolution rate and taste. Formulations with 4 percent Doshion, 8 percent CP and 4 percent SSG showed DT of 0.54, 0.35 and 1.23 minutes, respectively.

O cloridrato de diltiazem é bloqueador do canal de cálcio geralmente indicado para o tratamento de angina e de hipertensão e é extensamente biotransformado devido ao metabolismo hepático. A formulação do cloridrato de diltiazem em orodispersão pode prover rápida liberação com maior biodisponibilidade. O sabor amargo do fármaco deve ser mascarado para ser formulado em forma palatável. No presente trabalho tentou-se mascarar o sabor pela técnica de complexação, com uma orodispersão, usando superdesintegrantes, como Doshio P544, crospivodina (CP) e glicolato de amido sódico (SSG). Os complexos de cloridrato de diltiazem com β-CD (razão molar 1:1) foram preparados por mistura, coevaporação, comoagem, liofilização e métodos de fusão. A solubilidade de fase mostrou estabilidade constante de 819,13 M-1. Os complexos de inclusão preparados foram avaliados com relação ao mascaramento do sabor e caracterizados por IV, Difração de Raios X e DSC. Empregando-se o fármaco complexado com β-CD, prepararam-se comprimidos dispersíveis e avaliaram-se os mesmos quanto à dureza, friabilidade, variação de peso, espessura, tempo de desintegração (DT), taxa de dissolução e sabor. Formulações com 4 por cento de Doshion, 8 por cento de CP e 4 por cento de SSG mostraram DT de 0,54, 0,35 e 1,23 minutos, respectivamente.

Study of characteristic of the cochlear hydrops analysis masking procedure in normal adults / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the characteristic of the cochlear hydrops analysis masking procedure (CHAMP) in normal adults, and to evaluate the diagnostic values of its parameters for membranous labyrinth hydrops.</p><p><b>METHODS</b>Twenty otologically normal adults were recruited (male:female = 10:10), and their auditory brainstem responses (ABR) were obtained to six stimulus conditions using Bio-logic auditory evoked potential system: clicks presented alone (unmasked condition) and clicks presented with ipsilateral pink noise high-pass filtered at 8, 4, 2, 1, and 0.5 kHz respectively.</p><p><b>RESULTS</b>The wave V latency of ABR to the high-pass masking pink noise clicks were longer than ABR to clicks alone. The latency delays of wave V for clicks presented with ipsilateral pink noise high-pass filtered at 8, 4, 2, 1, and 0.5 kHz compared to clicks alone were (0.30 ± 0.18), (0.97 ± 0.43), (1.65 ± 0.64), (3.21 ± 0.56), (4.66 ± 0.37) ms respectively. The complex amplitude ratio between ABR to click + 0.5 kHz high-pass noise and click alone was 0.95 ± 0.11.</p><p><b>CONCLUSIONS</b>CHAMP is a promising diagnostic method for membranous labyrinth hydrops, and the latency delay of wave V might be used as the normal criterion. The specificity of the complex amplitude ratio need further evaluation in clinical work.</p>

Sound level of conditioned stimulus differs the plasticity of characteristic frequency in the rat cortical neurons / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Try to observe the plasticity of neuron in primary cortex of rat evoked by conditioned stimulus of different sound level.</p><p><b>METHODS</b>Applying conventional electrophysiological technique of extracellular recording to investigate the plasticity of characteristic frequency (CF) and frequency turning curve (FIC) of neurons in rat auditory cortex (AC) by determining CF shifts of neurons caused by sound stimulus of different sound level.</p><p><b>RESULTS</b>When the frequency difference between conditioned stimulus (CS) frequency and the CF of neuron was in 1.0 kHz, the plasticity of CF induced by CS was associated with sound level. The probability of the plasticity of CF evoked by CS of higher sound lever was more than the lower. And the probability was dependent on frequency turning curve (FTC) and almost independent on the sound level of conditioned signal.</p><p><b>CONCLUSION</b>Sound level of conditioned stimulus differs the plasticity of characteristic frequency of neurons in rat auditory cortex.</p>

Mascaramento clínico: aplicabilidade dos métodos platô e otimizado na pesquisa dos limiares auditivos / Clinical masking: applicability of plateau and optimized methods in hearing thresholds testing

BACKGROUND: many situations may raise difficulties when obtaining hearing thresholds for each ear separately. These situations demand the use of masking. The plateau method has been used for more than four decades. Nevertheless, in 2004 a different masking protocol was suggested, called the optimized method, to replace the plateau method in specific cases. AIM: to evaluate the feasibility of two clinical masking methods, plateau and optimized, in the testing of hearing thresholds. METHOD: participants of this study were 40 individuals aged 15 to 65 years, with either unilateral or bilateral hearing losses. All participants underwent air and bone conduction pure tone audiometry for both ears, with and without the use of the two masking methods, considering unilateral, bilateral, symmetrical and bone-only patterns. RESULTS: there was no statistically significant difference between the two masking methods for obtaining the air conduction hearing thresholds considering the tested situations. However, there was a higher percentage difference for the symmetrical pattern in the air conduction retest situation. There was a statistically significant difference between the plateau and optimized methods regarding the bone conduction thresholds for the symmetrical and bone-only patterns. CONCLUSION: the plateau method can be used for all patterns and the optimized method is the most effective for unilateral and bilateral patterns. Therefore, it is important for the audiologist to have the knowledge about the application of both masking methods in order to obtain more reliable results.

TEMA: na audiometria tonal liminar (ATL) algumas situações dificultam a obtenção dos limiares auditivos para cada orelha separadamente, havendo a necessidade do mascaramento. O método Platô, é o mais utilizado há mais de quatro décadas. Em 2004, foi sugerido um protocolo de mascaramento em que o método Otimizado substituiria o Platô, em casos específicos. OBJETIVO: analisar a aplicabilidade dos métodos Platô e Otimizado, na pesquisa dos limiares auditivos. MÉTODO: participaram deste estudo 40 indivíduos, de 15 a 65 anos, com perda auditiva unilateral ou bilateral. Foi realizada a ATL por via aérea (VA) e via óssea (VO), para ambas as orelhas, sem e com a utilização do mascaramento, segundo os padrões unilateral, bilateral, simétrico e somente-ósseo. RESULTADOS: não houve diferença estatisticamente significante entre os dois métodos para a obtenção dos limiares por VA, para os padrões avaliados. Contudo, houve um maior percentual de diferença para o padrão simétrico, durante reteste de VA. Houve diferença estatisticamente significante entre os métodos Platô e Otimizado, para a obtenção dos limiares por VO, para os padrões: simétrico e somente-ósseo. CONCLUSÃO: o Método Platô pode ser utilizado para todos os padrões e o Otimizado é mais eficaz para os padrões unilateral e bilateral. Desta forma, é necessário que o audiologista saiba diferenciar os melhores casos para a aplicação de um dos dois métodos e assim, obter resultados fidedignos.

Cor, iluminação e orientação do reverso de uma máscara facial não afetam a ilusão da máscara côncava / Color, illumination and orientation of a hollow mask do not affect the hollow-face illusion

Em condição monocular, 40 observadores julgaram o reverso côncavo de uma máscara facial monocromada cinza e de outra policromada (iluminados por cima, por baixo, pela direita e pela esquerda na posição vertical e na posição vertical invertida, iluminado por baixo) como côncavos, planos ou convexos. Além disso, as magnitudes dos seus relevos percebidos foram reproduzidas ao se esticar uma trena retrátil. Independente da cor, iluminação e orientação das máscaras, a maioria das respostas indicou que os reversos das máscaras foram percebidos como convexos. E mesmo nas poucas respostas em que as máscaras foram classificadas como planas, houve atribuição de relevo mensurável. Estes resultados confirmam que a ilusória profundidade da máscara facial côncava como convexa é robusta sob influência de variáveis diversas, o que sugere atuação predominante de processos de alta ordem sobre os processos de baixa ordem na percepção visual de faces.

With monocular viewing, forty observers judged a monochrome-gray and a polychrome hollow face mask (illuminated from above, from below, from the right and from the left, and upside-down illuminated form below) as inward deep, flat or outward deep. They were also asked to reproduce the perceived depth of the mask by pulling out a tape measure. Regardless of color, illuminating condition and mask orientation, most of the responses indicated that the hollow faces were perceived as outward deep. Even in the few occasions in which the masks were reported flat, measurable depths were assigned on the tape measure. These results support that the hollow face illusion is robust even under diverse variable effects, which suggest preponderant top-down over bottom-up processes on visual face perception.

Evaluation test and masking therapy of subjective tinnitus / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To undergo tinnitus evaluation test and masking therapy of subject tinnitus associated with sensorineural hearing loss as a reference for diagnosis and guiding masking therapy.</p><p><b>METHODS</b>The 66 patients with subject tinnitus were diagnosed as sensorineural hearing loss. Sixty-six patients divide into three groups according to the results of pure tone audiometry, including steep drop type in 28 patients, slow drop type in 20 patients, and flat type in 18 patients. All the patients underwent tinnitus evaluation tests (pitch matching, intensity matching, tinnitus masking curves, residual inhibition) and masking therapy.</p><p><b>RESULTS</b>Tinnitus with steep drop type manifest was as low intensity [average intensity (5.7 +/- 2.9) dB (x(-) +/- s)] and high frequency (median with 4750 Hz). Residual inhibition was almost positive, but was usually consistent with convergence and congruence tinnitus masking curves. Masking therapy had better effect in the treatment of this type of tinnitus (effective rate 89.3%). Tinnitus with slow drop type manifest was as low intensity [average intensity: (6.2 +/- 4.8) dB] and high frequency (median: 4050 Hz). The distribution of residual inhibition and tinnitus masking curves had no obviously characteristics. The effective rate of masking therapy of this type of tinnitus (55.0%) was higher than tinnitus with flat type but low than that of tinnitus with steep drop type. The intensity of tinnitus with flat type [average intensity: (9.2 +/- 5.0) dB] was higher than that of the previous groups. The distribution of frequency of this type had no obviously characteristics. The residual inhibition was almost negative, and was usually consistent with divergence and persistence tinnitus masking curves. Masking therapy had unsatisfactory curative effect in the treatment of this type of tinnitus (effective rate 11.1%). The effective rate of masking therapy was significant differences among the three groups (chi(2) = 9.127, P < 0.05).</p><p><b>CONCLUSIONS</b>For the tinnitus patients with steep drop type audiometric curve, they are recommended masking therapy. For the tinnitus patients with slow drop type audiometric curve, masking therapy may be attempted to perform. For the tinnitus patients with flat type audiometric curve, they do not recommend the masking therapy.</p>