Wideband Acoustic Absorbance in Otosclerosis: Does Stapedotomy Restore Normal Tympanic Cavity Function?

Abstract Introduction Otosclerosis is characterized by the fixation of the stapes to the oval window, thereby impairing acoustic signal absorbance. A commonly used surgical technique for improving hearing in cases of otosclerosis is stapedotomy. However, it is unclear whether this surgery restores all the physical characteristics of the tympano-ossicular system. Objective To evaluate the tympano-ossicular system in individuals with fenestral otosclerosis pre and poststapedotomy using wideband tympanometry. Method A total of 47 individuals and 71 ears were assessed. The subjects were divided into three groups: presurgery otosclerosis; postsurgery; and a control group of normal-hearing adults. A handheld tympanometer with a wideband module (226-8,000 Hz) was used to take measurements at ambient pressure and under pressurized conditions. The level of statistical significance adopted was p ≤ 0.05. Results Acoustic absorbance at 226 Hz was low for all groups. At frequencies in the range 630 to 5,040 Hz, each group had a characteristic absorbance curve, allowing them to be distinguished from one another. In the presurgery group, absorbance values were below normal levels, with energy absorbance below 10%. Low energy absorbance was most evident at 1,000 Hz in the presurgery group, but this was not observed in the postsurgery group. Although there was an improvement in hearing, the surgery failed to restore the tympano-ossicular system to normal. Conclusion Wideband acoustic absorbance proved able to differentiate normal ears and otosclerotic ears pre and postsurgery, under both ambient pressure and pressurized conditions.

Wideband Acoustic Absorbance in Otosclerosis: Does Stapedotomy Restore Normal Tympanic Cavity Function?

Introduction Otosclerosis is characterized by the fixation of the stapes to the oval window, thereby impairing acoustic signal absorbance. A commonly used surgical technique for improving hearing in cases of otosclerosis is stapedotomy. However, it is unclear whether this surgery restores all the physical characteristics of the tympano-ossicular system. Objective To evaluate the tympano-ossicular system in individuals with fenestral otosclerosis pre and poststapedotomy using wideband tympanometry. Method A total of 47 individuals and 71 ears were assessed. The subjects were divided into three groups: presurgery otosclerosis; postsurgery; and a control group of normal-hearing adults. A handheld tympanometer with a wideband module (226-8,000 Hz) was used to take measurements at ambient pressure and under pressurized conditions. The level of statistical significance adopted was p ≤ 0.05. Results Acoustic absorbance at 226 Hz was low for all groups. At frequencies in the range 630 to 5,040 Hz, each group had a characteristic absorbance curve, allowing them to be distinguished from one another. In the presurgery group, absorbance values were below normal levels, with energy absorbance below 10%. Low energy absorbance was most evident at 1,000 Hz in the presurgery group, but this was not observed in the postsurgery group. Although there was an improvement in hearing, the surgery failed to restore the tympano-ossicular system to normal. Conclusion Wideband acoustic absorbance proved able to differentiate normal ears and otosclerotic ears pre and postsurgery, under both ambient pressure and pressurized conditions.

Distortion Product Otoacoustic Emission Component Behavior as a Function of Primary Frequency Ratio and Primary Level.

OBJECTIVES: Distortion product otoacoustic emissions (DPOAEs) are composed of distortion and reflection components. Much is known about the influence of the stimulus frequency ratio (f 2 /f 1 ) on the overall/composite DPOAE level. However, the influence of f 2 /f 1 on individual DPOAE components is not as well examined. The goals of this pilot study were to systematically evaluate the effects of f 2 /f 1 on DPOAE components in clinically normal-hearing young adult ears. To extend the limited reports in the literature, this examination was carried out over an extended frequency range using two stimulus-level combinations. DESIGN: DPOAEs were recorded from seven normal-hearing, young adult ears for f 2 frequencies between 0.75 and 16 kHz over a range of f 2 /f 1 using two stimulus-level combinations. The distortion (DPOAE D ) and reflection (DPOAE R ) components were separated using an inverse fast Fourier transform algorithm. Optimal ratios for the composite DPOAE and DPOAE components were determined from smoothed versions of level versus ratio functions in each case. RESULTS: The optimal ratio for the composite DPOAE level increased with stimulus level and decreased as a function of frequency above 1 kHz. The optimal ratios for the DPOAE components followed a similar trend, decreasing with increasing frequency. The optimal ratio for DPOAE D was generally higher than that for DPOAE R . The overall level for DPOAE D was greater than that of DPOAE R , both decreasing with increasing frequency. DPOAE R , but not DPOAE D , became unrecordable above the noise floor at the higher frequencies. CONCLUSIONS: DPOAE components behave similarly but not identically as a function of f 2 /f 1 . The ear canal DPOAE is generally dominated by DPOAE D . The behavior of DPOAE D as a function of f 2 /f 1 is entirely consistent with known properties of cochlear mechanics. The behavior of DPOAE R is more variable across ears, perhaps reflective of the increased number of parameters that influence its final form. Attempting to use an f 2 /f 1 that would allow a greater bias of the ear canal DPOAE toward one component or the other does not appear to be practical.

Analysis of wideband tympanometry in Ménière's disease / Análise da timpanometria de banda larga na doença de Ménière

Abstract Introduction: Endolymphatic hydrops is the pathophysiological substrate of Ménière's disease. The changes in the inner ear, transmitted to the middle ear through changes in the ossicular chain mobility, can be quantified by wideband tympanometry, through the measurement of the acoustic absorbance at multiple frequencies, represented by the sound energy absorbed by the middle ear, even at its early stages. Studying the behavior of the middle ear through the absorbance in patients with endolymphatic hydrops under ambient pressure and under peak pressure can be useful for detecting Ménière's disease. Objective: To characterize acoustic absorbance behavior in subjects with symptomatic and asymptomatic Ménière's disease compared to controls, in order to verify the ability of wideband tympanometry to detect Ménière's disease. Methods: We carried out a cross-sectional study with a diagnostic approach comparing the findings of wideband tympanometry at ambient pressure and peak pressure between the ears of the control group (n = 30), the asymptomatic group (n = 21) and the symptomatic group (n = 9). Results: Different peak pressure values were found between the ears of the control group (0daPa), the asymptomatic group (−11 daPa) and the symptomatic group (−192 daPa), with p < 0.05 by the Kruskal-Wallis test, Mann Whitney test and Bonferroni correction. Different absorbance values were found between the ears of the symptomatic group and the asymptomatic group compared to the control group for low frequencies at ambient pressure and peak pressure, with p < 0.05 by the Kruskal-Wallis test, Mann Whitney test and Bonferroni correction. Conclusions: The Wideband Tympanometry test was capable of identifying the presence of Ménières disease, and to differentiate between asymptomatic and symptomatic patients, when comparing them with healthy individuals.

Resumo Introdução: A hidropsia endolinfática é o substrato fisiopatológico da doença de Ménière. As alterações desencadeadas na orelha interna, transmitidas à orelha média pelas modificações na mobilidade da cadeia ossicular, podem ser quantificadas pela timpanometria de banda larga, através da medida da absorvância acústica sob múltiplas frequências, representadas pela energia sonora absorvida pela orelha média, mesmo em estágios iniciais de sua instalação. Estudar o comportamento da orelha média através da absorvância em pacientes com hidropisia endolinfática sob pressão ambiente e sob o pico de pressão pode ser útil na detecção da doença de Ménière. Objetivo: Caracterizar o comportamento da absorvância em indivíduos com diagnóstico da doença de Ménière sintomáticos e assintomáticos, comparados com controles, a fim de verificar a capacidade da timpanometria de banda larga em detectar variações clínicas relacionadas a possível hidropisia endolinfática. Método: Foi realizado um estudo transversal, com enfoque diagnóstico, que comparou os achados da timpanometria de banda larga na pressão ambiente e no pico de pressão entre orelhas do grupo controle (n = 30), grupo assintomático (n = 21) e grupo sintomático (n = 9). Resultados: Foram encontrados valores do pico de pressão diferentes entre orelhas do grupo controle (0 daPa), do grupo assintomático (-11 daPa) e do grupo sintomático (-192 daPa), com p <0,05 pelos testes de Kruskal-Wallis, Mann Whitney e correção de Bonferroni. Foram encontrados valores de absorvância diferentes entre orelhas do grupo sintomático e do grupo assintomático em relação ao grupo controle para as frequências baixas na pressão ambiente e na pressão de pico, com p < 0,05 pelos testes de Kruskal-Wallis, Mann Whitney e correção de Bonferroni. Conclusão: A timpanometria de banda larga foi um teste capaz de identificar a presença da doença de Ménière e de diferenciar os pacientes assintomáticos e sintomáticos, comparando-os com indivíduos hígidos.

Analysis of wideband tympanometry in Ménière's disease.

INTRODUCTION: Endolymphatic hydrops is the pathophysiological substrate of Ménière's disease. The changes in the inner ear, transmitted to the middle ear through changes in the ossicular chain mobility, can be quantified by wideband tympanometry, through the measurement of the acoustic absorbance at multiple frequencies, represented by the sound energy absorbed by the middle ear, even at its early stages. Studying the behavior of the middle ear through the absorbance in patients with endolymphatic hydrops under ambient pressure and under peak pressure can be useful for detecting Ménière's disease. OBJECTIVE: To characterize acoustic absorbance behavior in subjects with symptomatic and asymptomatic Ménière's disease compared to controls, in order to verify the ability of wideband tympanometry to detect Ménière's disease. METHODS: We carried out a cross-sectional study with a diagnostic approach comparing the findings of wideband tympanometry at ambient pressure and peak pressure between the ears of the control group (n = 30), the asymptomatic group (n = 21) and the symptomatic group (n = 9). RESULTS: Different peak pressure values were found between the ears of the control group (0 daPa), the asymptomatic group (-11 daPa) and the symptomatic group (-192 daPa), with p < 0.05 by the Kruskal-Wallis test, Mann Whitney test and Bonferroni correction. Different absorbance values were found between the ears of the symptomatic group and the asymptomatic group compared to the control group for low frequencies at ambient pressure and peak pressure, with p < 0.05 by the Kruskal-Wallis test, Mann Whitney test and Bonferroni correction. CONCLUSIONS: The Wideband Tympanometry test was capable of identifying the presence of Ménière´s disease, and to differentiate between asymptomatic and symptomatic patients, when comparing them with healthy individuals.

Frequency-Following Response (FFR) in Military Pilots.

Introduction Good hearing in pilots, including central auditory skills, is critical for flight safety and the prevention of aircraft accidents. Pure tone audiometry alone may not be enough to assess hearing in the members of this population who, in addition to high noise levels, routinely face speech recognition tasks in non-ideal conditions. Objective To characterize the frequency-following response (FFR) of a group of military pilots compared with a control group. Methods Twenty military pilots in the Study Group and 20 non-pilot military personnel, not exposed to noise in their work, in the Control Group, all with normal hearing, aged between 30 and 40 years old, completed a questionnaire to assess their hearing habits, and their FFRs were measured with a /da/ syllable (duration 40 milliseconds, speed 10.9/s), at 80 dB NA in the right ear. All procedures were approved by the ethical committee of the institution. Statistical analysis was performed using the t-Student or Mann-Whitney tests for quantitative variables, and the Fisher or chi-squared tests for qualitative variables, and a value of p < 0.05 was considered to be statistically significant. Results There was no significant difference between the groups regarding auditory habits. In the FFR, wave amplitudes A ( p = 0.01) and C ( p = 0.04) were significantly lower in the Study Group. Conclusion Working as a military pilot can be a crucial factor in determining an individual's typical FFR pattern, demonstrated in the present study by statistically significant reductions in the amplitudes of the A and C waves.

Cortical auditory-evoked potential as a biomarker of central auditory maturation in term and preterm infants during the first 3 months.

OBJECTIVES: To analyze central auditory maturation in term and preterm infants during the first 3 months of life by comparing the latency and amplitude of cortical auditory-evoked potential at different frequencies. METHODS: In this study, 17 term and 18 preterm infants were examined; all had tested positive on the neonatal hearing screening test. Cortical auditory potential was investigated during the first and third months of life. The response of the cortical auditory-evoked potential was investigated at frequencies of 500, 1000, 2000, and 4000 Hz. The latency and amplitude of the cortical response were automatically detected and manually analyzed by three researchers with experience in electrophysiology. The results were compared using analysis of variance and the Bonferroni test. A significance level of 5% was used for all analyses. RESULTS: Latency values of cortical auditory-evoked potential in the first month of birth were significantly higher than those in the third month, and latency values of the preterm group were higher than those of the term group, regardless of the frequency and time of evaluation. In general, the latency of the cortical auditory-evoked potential was higher at high frequencies. Amplitude values in the third month of life were significantly higher than those in the first month for term and preterm infants. CONCLUSION: Central auditory maturation was observed in both groups but with different results between those born at term and preterm, with latencies of cortical auditory-evoked potential higher for the preterm group and at high frequencies.

Automated analysis of bone-conduction cortical auditory evoked potential in normal-hearing neonates / Análise automática do potencial evocado auditivo cortical por via óssea em neonatos norma-ouvintes

Abstract Introduction The cortical auditory evoked potential allows the possibility of objectively evaluating the entire auditory system, which is desirable in the pediatric population. Bone conduction auditory stimulation is recommended in the differential diagnosis of conductive hearing loss. However, there are not many studies of cortical auditory evoked potential using bone conduction. Objective The aim of this study was to characterize the response of cortical auditory evoked potential through bone conduction in normal-hearing neonates using an automated response analysis equipment. Methods This study included 30 normal-hearing neonates, without risk factors for hearing loss. The equipment used was the HEARlab automated response analysis and the cortical responses were evaluated at the frequencies of 500-4000 Hz through bone conduction, at intensity ranging from 0 to 60 dBnHL. The latencies and amplitudes were manually marked by experienced judges. Results Cortical auditory evoked potential responses were detected in 100% of the evaluated subjects and there was no difference regarding the cortical response of the neonates in relation to the variables of gender, ear and masking use. At an intensity of 60 dBnHL for the frequencies of 500, 1000, 2000 and 4000 Hz the latencies were 234; 241; 239 and 253 ms and the amplitudes were 15.6; 8.4; 6.2; 6.3 µV. The mean thresholds were 23.6; 28; 31 and 33.1 dBnHL, respectively. Conclusion It was possible to measure the cortical auditory evoked potential response in the neonatal population using bone vibrator as sound transducer and to draw the profile of the cortical auditory evoked potential latencies and amplitudes by frequencies at the intensity of 60 dBnHL and at the threshold.

Resumo Introdução O potencial evocado auditivo cortical traz a possibilidade de avaliar de forma objetiva todo o sistema auditivo, o que é desejável na população infantil. A estimulação auditiva por condução óssea é recomendada no diagnóstico diferencial da perda auditiva condutiva. Entretanto, não há muitos estudos de potencial evocado auditivo cortical com o uso do vibrador ósseo. Objetivo Caracterizar a resposta do potencial evocado auditivo cortical por vibrador ósseo em neonatos normo-ouvintes com equipamento de análise automática de resposta. Metodologia A pesquisa incluiu 30 neonatos normo-ouvintes e sem fator de risco para deficiência auditiva. Foi usado o equipamento de análise automática de resposta HEARlab e foram avaliadas as repostas corticais na frequências de 500 a 4000 Hz por vibrador ósseo, na intensidade de 0 a 60 dBnNA. As latências e amplitudes foram marcadas manualmente por juízes experientes. Resultados Foram detectadas respostas de potencial evocado auditivo cortical em 100% dos sujeitos avaliados. Não houve diferença na resposta cortical dos neonatos para as variáveis: sexo, orelha e uso do mascaramento. Para as frequências de 500, 1000, 2000 e 4000 Hz foram observadas as latências de 234; 241; 239 e 253 ms, as amplitudes de 15,6; 8,4; 6,2; 6,3 µV, na intensidade de 60 dBnNA, e os limiares médios de 23,6; 28; 31 e 33,1 dBnNA, respectivamente. Conclusão Foi possível obter a resposta do potencial evocado auditivo cortical na população neonatal com vibrador ósseo como transdutor de som e traçar o perfil das latências e amplitudes dos potencial evocado auditivo cortical por frequência nas intensidades de 60 dBnNA e no limiar.

Masking level difference among brazilian military personnel: a comparison between pilots and non-pilots.

OBJECTIVES: The aims of this study were to investigate auditory habits and binaural interaction among pilot and non-pilot military personnel from the Brazilian Air Force. DESIGN: A cross-sectional study using (1) an auditory habits questionnaire to outline the groups auditory profile and (2) the masking level difference test (MLD, Auditec, Saint Louis®) to evaluate and compare the groups. STUDY SAMPLE: Forty military male personnel aged between 30-40 years old, all with normal hearing, comprising 20 pilots in the study group (SG), and 20 non-pilots, not exposed to noise, in the control group (CG). RESULTS: There was no significant difference between groups regarding auditory habits. In the MLD test, a significantly better performance under the homophasic condition (S0N0) was found in the SG. Under the antiphasic condition (SπN0) there were no differences between groups. This combination resulted in a significantly lower MLD in the SG compared to the CG. CONCLUSIONS: Repeated exposure to conditions where active pilots have to learn to recognise speech in noisy backgrounds may lead to a better performance in the MLD's homophasic condition (S0N0).

Emissões otoacústicas em neonatos expostos ao fumo durante a gestação / Otoacoustic emissions in neonates exposed to smoke during pregnancy

Resumo Introdução: As substâncias tóxicas presentes na fumaça do cigarro podem danificar as células ciliadas da cóclea. Esse efeito foi investigado pela mensuração das emissões otoacústicas. Objetivo: Investigar o impacto de estímulos nas emissões otoacústicas, comparar neonatos com e sem exposição à fumaça de cigarro durante a gestação. Método: Testes de emissões otoacústicas evocadas transientes, evocadas por estímulo tipo clique e emissões otoacústicas por produto de distorção, evocadas por dois tons, foram feitos em ambas as orelhas, com um aparelho Interacoustic TITAN. O estudo incluiu 105 neonatos divididos em dois grupos: um grupo de estudo, que compreendeu 47 neonatos expostos à fumaça durante a gravidez; e um grupo controle constituído por 58 neonatos que não foram expostos. Todos os participantes apresentaram triagem auditiva neonatal normal. Resultados: Não foram encontradas diferenças estatísticas nos níveis de resposta das emissões otoacústicas por produto de distorção entre os grupos. Nos testes de emissões otoacústicas evocadas transientes, foram observados menores níveis de resposta no grupo de estudo do que no grupo controle na análise de bandas de frequências da orelha direita, com diferenças estatisticamente significantes nos sinais e relação sinal-ruído (exceto a 1 kHz). Conclusão: O impacto da exposição ao fumo pôde ser analisado por meio das emissões otoacústicas evocadas transientes em neonatos. O efeito da exposição à fumaça durante a gravidez foi evidenciado por uma redução nos níveis das emissões otoacústicas evocadas transientes no grupo exposto. Esse mesmo efeito não foi observado para as análises feitas nos níveis das emissões otoacústicas por produto de distorção.

Cochlear tuning estimates from level ratio functions of distortion product otoacoustic emissions.

Objective: Distortion product otoacoustic emission (DPOAE) levels plotted as a function of stimulus frequency ratio demonstrate a bandpass shape. This bandpass shape is narrower at higher frequencies compared to lower frequencies and thus has been thought to be related to cochlear mechanical tuning.Design: However, the frequency- and level-dependence of these functions above 8 kHz is largely unknown. Furthermore, how tuning estimates from these functions are related to behavioural tuning is not fully understood.Study Sample: From experiment 1, we report DPOAE level ratio functions (LRF) from seven normal-hearing, young-adults for f2 = 0.75-16 kHz and two stimulus levels of 62/52 and 52/37 dB FPL. We found that LRFs became narrower as a function of increasing frequency and decreasing level.Results: Tuning estimates from these functions increased as expected from 1-8 kHz. In experiment 2, we compared tuning estimates from DPOAE LRF to behavioural tuning in 24 normal-hearing, young adults for 1 and 4 kHz and found that behavioural tuning generally predicted DPOAE LRF estimated tuning.Conclusions: Our findings suggest that DPOAE LRFs generally reflect the tuning profile consistent with basilar membrane, neural, and behavioural tuning. However, further investigations are warranted to fully determine the use of DPOAE LRF as a clinical measure of cochlear tuning.

Automated analysis of bone-conduction cortical auditory evoked potential in normal-hearing neonates.

INTRODUCTION: The cortical auditory evoked potential allows the possibility of objectively evaluating the entire auditory system, which is desirable in the pediatric population. Bone conduction auditory stimulation is recommended in the differential diagnosis of conductive hearing loss. However, there are not many studies of cortical auditory evoked potential using bone conduction. OBJECTIVE: The aim of this study was to characterize the response of cortical auditory evoked potential through bone conduction in normal-hearing neonates using an automated response analysis equipment. METHODS: This study included 30 normal-hearing neonates, without risk factors for hearing loss. The equipment used was the HEARlab automated response analysis and the cortical responses were evaluated at the frequencies of 500-4000Hz through bone conduction, at intensity ranging from 0 to 60dBnHL. The latencies and amplitudes were manually marked by experienced judges. RESULTS: Cortical auditory evoked potential responses were detected in 100% of the evaluated subjects and there was no difference regarding the cortical response of the neonates in relation to the variables of gender, ear and masking use. At an intensity of 60 dBnHL for the frequencies of 500, 1000, 2000 and 4000Hz the latencies were 234; 241; 239 and 253ms and the amplitudes were 15.6; 8.4; 6.2; 6.3µV. The mean thresholds were 23.6; 28; 31 and 33.1dBnHL, respectively. CONCLUSION: It was possible to measure the cortical auditory evoked potential response in the neonatal population using bone vibrator as sound transducer and to draw the profile of the cortical auditory evoked potential latencies and amplitudes by frequencies at the intensity of 60dBnHL and at the threshold.

Otoacoustic emissions in neonates exposed to smoke during pregnancy.

INTRODUCTION: The toxic substances present in cigarette smoke can damage cochlea hair cells. This effect has been investigated by measuring otoacoustic emissions. OBJECTIVE: To investigate the impact of stimuli on otoacoustic emissions, comparing neonates with and without exposure to cigarette smoke during pregnancy. METHODS: Transient-evoked otoacoustic emissions, evoked by a click stimulus, and distortion product otoacoustic emissions, evoked by two tones tests were conducted in both ears, using an Interacoustic TITAN device. The study included 105 neonates divided into two groups: a study group, comprising 47 neonates exposed to smoke during pregnancy; and a control group comprized of 58 neonates who were not exposed. All participants had normal neonatal hearing screening. RESULTS: No statistical differences in distortion product otoacoustic emissions response levels were found between the groups. In the transient-evoked otoacoustic emissions tests lower response levels were observed in the study group than the control group in frequency band analysis of the right ear, with statistically significant differences in signals and signal-noise ratio (except at 1kHz). CONCLUSION: The impact of smoking exposure could be analyzed through transient-evoked otoacoustic emissions in neonates. The group effect of smoke exposure during pregnancy was evidenced by a reduction in transient-evoked otoacoustic emissions levels. This same effect was not observed for the analyses performed on distortion product otoacoustic emissions levels.

Cortical auditory-evoked potential as a biomarker of central auditory maturation in term and preterm infants during the first 3 months

OBJECTIVES: To analyze central auditory maturation in term and preterm infants during the first 3 months of life by comparing the latency and amplitude of cortical auditory-evoked potential at different frequencies. METHODS: In this study, 17 term and 18 preterm infants were examined; all had tested positive on the neonatal hearing screening test. Cortical auditory potential was investigated during the first and third months of life. The response of the cortical auditory-evoked potential was investigated at frequencies of 500, 1000, 2000, and 4000 Hz. The latency and amplitude of the cortical response were automatically detected and manually analyzed by three researchers with experience in electrophysiology. The results were compared using analysis of variance and the Bonferroni test. A significance level of 5% was used for all analyses. RESULTS: Latency values of cortical auditory-evoked potential in the first month of birth were significantly higher than those in the third month, and latency values of the preterm group were higher than those of the term group, regardless of the frequency and time of evaluation. In general, the latency of the cortical auditory-evoked potential was higher at high frequencies. Amplitude values in the third month of life were significantly higher than those in the first month for term and preterm infants. CONCLUSION: Central auditory maturation was observed in both groups but with different results between those born at term and preterm, with latencies of cortical auditory-evoked potential higher for the preterm group and at high frequencies.

Cortical auditory evoked potential in assessment of neonates: a study about minimum level of responses in term and preterm newborns / Potencial evocado auditivo cortical na avaliac¸ão de neonatos: um estudo sobre o nível mínimo de respostas em nascidos a termo e pré-termos

Abstract Introduction: The study of the threshold level of cortical auditory response in adults has been investigated in previous studies. Due to maturational issues, little is known about these responses in neonates. Technological advances with automatic analysis devices now allow investigation in specific populations. Thus, new studies are needed to establish the feasibility of using this auditory potential to identify the lowest levels of responses in children. Objective: Verify and compare latency and amplitude in 80 dBnNA and the minimum level of cortical auditory response in term and preterm neonates. Methods: A cross-sectional, comparative study involving 59 neonates, 35 full-term births and 24 preterm births, with positive results in the Neonatal Hearing Screening. The Hearlab system was used to investigate the P1i auditory potential with tone burst stimulus at frequencies of 500, 1000, 2000 and 4000 Hz. The minimum response level search ranged from 80 to 0 dBNA and was detected automatically. The results were compared between groups, evaluating the latency and amplitude in 80 dBNA and the minimum level of cortical auditory response. Results: The mean values obtained for the minimum level of cortical auditory response in term group were 26 ± 8.81; 26.14 ± 6.97; 29 ± 7.65 and 29.43 ± 7.04 dBNA and for preterm neonates of 31.96 ± 10.41; 34.13 ± 11.34; 33.64 ± 11.03 and 37.73 ± 11.92 dBNA, for the frequencies of 500, 1000, 2000 and 4000 Hz, respectively. There was a difference between groups for the latency of P1i at 4000 Hz and the minimum response levels at 500, 1000 and 4000 Hz, with higher values for preterm infants. Conclusion: It was possible to obtain latency and amplitude values at 80 dBnNA and the minimum level of cortical response in term and preterm newborns, with different results between groups, with higher values in those born preterm.

Resumo Introdução: A investigação do nível mínimo de resposta auditiva cortical tem sido alvo de diferentes estudos em adultos. Devido a questões de maturação, pouco se sabe sobre essas respostas em recém-nascidos. Com o avanço tecnológico, dispositivos de análise automática surgiram com o objetivo de retomar essa avaliação em populações específicas. Assim, novos estudos são necessários para verificar a viabilidade do uso desse potencial auditivo na obtenção de níveis mínimos de respostas na criança. Objetivo: Verificar e comparar latência e amplitude em 80 dBnNA e o nível mínimo de resposta auditiva cortical em recém-nascidos a termo e pré-termo. Método: Estudo transversal, comparativo, envolvendo 59 neonatos, 35 nascidos a termo e 24 pré-termos, com resultados positivos na triagem auditiva neonatal. O sistema Hearlab foi utilizado para investigar o potencial auditivo P1i com estímulo tone burst nas frequências de 500, 1000, 2000 e 4000 Hz. A busca do nível mínimo de resposta variou de 80 a 0 dBNA e foi detectado automaticamente. Os resultados foram comparados entre os grupos, avaliando a latência e amplitude em 80 dBNA e o nível mínimo de resposta auditiva cortical. Resultados: Os valores médios obtidos para o nível mínimo de resposta auditiva cortical no grupo nascido a termo foram 26 ± 8,81; 26,14 ± 6,97; 29 ± 7,65 e 29,43 ± 7,04 dBNA e para recém-nascidos pré-termos foram de 31,96 ± 10,41; 34,13 ± 11,34; 33,64 ± 11,03 e 37,73 ± 11,92 dBNA, para as frequências de 500, 1000, 2000 e 4000 Hz, respectivamente. Houve diferenc¸a entre os grupos para a latência de P1i em 4000 Hz e os níveis mínimos de resposta em 500, 1000 e 4000 Hz, com valores maiores em Pré-termos. Conclusão: Foi possível obter valores de latência e amplitude em 80 dBnNA e o nível mínimo de resposta cortical em recém-nascidos a termo e Pré-termos, com resultados diferentes entre osgrupos, com valores maiores em pré-termos.

Frequency-following response (FFR) with speech stimulus in normal-hearing young adults. / Frequency-following response (FFR) com estímulo de fala em jovens adultos normo-ouvintes.

PURPOSE: Analyze the slope, latency and amplitude values of the waveforms V, A, C, D, E, F and O from Frequency-following Response (FFR) with speech stimulus in normal-hearing adults based on a recent international reference study. METHOD: Eleven normal-hearing adults aged 18-30 years, without hearing complaints, were evaluated in this study using an Intelligent Hearing Systems device. The speech stimulus /da/ was presented to the right ear via insertion phone and the responses were captured by electrodes placed on the vertex, right mastoid bone, and forehead (ground). RESULTS: The descriptive latency values of the components were V 6.50, A 7.87, C 17.74, D 22.77, E 32.07, F 40.03 and O 48.07 ms. The mean amplitude measures of the waves were V 0.17, A -0.12, C -0.14, D -0.14, E -0.20, F -0.22 and O -0.14 µV. The mean slope value was 0.23. Comparison with an international study, Krizman et al. (2012), showed that most of the results are within positive and negative standard deviation values for the assessed age group for slope, latency and amplitude. CONCLUSION: The electrophysiological measures obtained from Frequency-following Response using the speech stimulus / da/ in normal-hearing adults without hearing complaints showed slope, latency and amplitude values of all FFR components within the normality standard described in the international literature.

OBJETIVO: Analisar o slope e as latências e amplitudes das ondas V, A, C, D, E, F e da Frequency-Following Response, com estímulo de fala, em adultos com audição normal, tendo como base referência internacional. MÉTODO: Onze adultos normo- ouvintes com idade entre 18 e 30 anos, sem queixas auditivas, foram avaliados na pesquisa. O equipamento utilizado foi o Intelligent Hearing System. O estímulo de fala /da/ foi apresentado por meio de fone de inserção na orelha direita e a resposta foi captada por meio de eletrodos posicionados no vértex, na mastoide direita e eletrodo terra na fronte. RESULTADOS: Os valores descritivos de latência dos componentes foram: V 6,50, A 7,87, C 17,74, D 22,77, E 32,07, F 40,03 e O 48,07 ms. As médias de amplitude foram V 0,17, A -0,12, C -0,14, D -0,14, E -0,20, F -0,22 e O -0,14 µV. A média do valor do slope encontrada foi 0,23. Na comparação com estudo de referência internacional, Krizman et al. (2012) mostraram que a maioria dos resultados se encontra dentro de um desvio padrão positivo e negativo para a faixa etária estudada tanto para o slope quanto para as latências e amplitudes. CONCLUSÃO: A resposta eletrofisiológica da Frequency Following Response, utilizando o estímulo de fala /da/, em adultos com audição normal e sem queixas auditivas, apresentou valores de slope e de latência e amplitude de todos os componentes dentro do padrão de normalidade apresentado pela literatura internacional.

Cortical auditory evoked potential in assessment of neonates: a study about minimum level of responses in term and preterm newborns.

INTRODUCTION: The study of the threshold level of cortical auditory response in adults has been investigated in previous studies. Due to maturational issues, little is known about these responses in neonates. Technological advances with automatic analysis devices now allow investigation in specific populations. Thus, new studies are needed to establish the feasibility of using this auditory potential to identify the lowest levels of responses in children. OBJECTIVE: Verify and compare latency and amplitude in 80dBnNA and the minimum level of cortical auditory response in term and preterm neonates. METHODS: A cross-sectional, comparative study involving 59 neonates, 35 full-term births and 24 preterm births, with positive results in the Neonatal Hearing Screening. The Hearlab system was used to investigate the P1i auditory potential with tone burst stimulus at frequencies of 500, 1000, 2000 and 4000Hz. The minimum response level search ranged from 80 to 0dBNA and was detected automatically. The results were compared between groups, evaluating the latency and amplitude in 80dBNA and the minimum level of cortical auditory response. RESULTS: The mean values obtained for the minimum level of cortical auditory response in term group were 26±8.81; 26.14±6.97; 29±7.65 and 29.43±7.04dBNA and for preterm neonates of 31.96±10.41; 34.13±11.34; 33.64±11.03 and 37.73±11.92dBNA, for the frequencies of 500, 1000, 2000 and 4000Hz, respectively. There was a difference between groups for the latency of P1i at 4000Hz and the minimum response levels at 500, 1000 and 4000Hz, with higher values for preterm infants. CONCLUSION: It was possible to obtain latency and amplitude values at 80dBnNA and the minimum level of cortical response in term and preterm newborns, with different results between groups, with higher values in those born preterm.

Automated cortical auditory evoked potentials threshold estimation in neonates / Estimativa do limiar de potenciais evocados auditivos corticais automatizados em recém-nascidos

Abstract Introduction: The evaluation of cortical auditory evoked potential has been the focus of scientific studies in infants. Some authors have reported that automated response detection is effective in exploring these potentials in infants, but few have reported their efficacy in the search for thresholds. Objective: To analyze the latency, amplitude and thresholds of cortical auditory evoked potential using an automatic response detection device in a neonatal population. Methods: This is a cross-sectional, observational study. Cortical auditory evoked potentials were recorded in response to pure-tone stimuli of the frequencies 500, 1000, 2000 and 4000 Hz presented in an intensity range between 0 and 80 dB HL using a single channel recording. P1 was performed in an exclusively automated fashion, using Hotelling's T2 statistical test. The latency and amplitude were obtained manually by three examiners. The study comprised 39 neonates up to 28 days old of both sexes with presence of otoacoustic emissions and no risk factors for hearing loss. Results: With the protocol used, cortical auditory evoked potential responses were detected in all subjects at high intensity and thresholds. The mean thresholds were 24.8 ± 10.4 dB NA, 25 ± 9.0 dB NA, 28 ± 7.8 dB NA and 29.4 ± 6.6 dB HL for 500, 1000, 2000 and 4000 Hz, respectively. Conclusion: Reliable responses were obtained in the assessment of cortical auditory potentials in the neonates assessed with a device for automatic response detection.

Resumo Introdução: O potencial evocado auditivo cortical tem sido o foco de estudos científicos. Alguns autores observaram que a detecção automatizada de respostas é eficaz na exploração desses potenciais em lactentes, mas poucos relataram sua eficácia na busca de limiares. Objetivo: Analisar a latência, a amplitude e os limiares do potencial evocado auditivo cortical em recém-nascidos, com o uso de um dispositivo de detecção automática de resposta. Método: Estudo transversal, observacional. Os potenciais evocados auditivos corticais foram registrados em resposta a estímulos de tons puros nas frequências de 500, 1000, 2000 e 4000 Hz e apresentados em uma faixa de intensidade entre 0-80 dBNA, com o uso de gravação de canal único. O P1 foi feito de forma exclusivamente automática, com o uso do teste estatístico T2 de Hotelling. A latência e a amplitude foram obtidas manualmente por três examinadores. O estudo incluiu 39 recém-nascidos com até 28 dias de ambos os sexos, com presença de emissões otoacústicas e sem fatores de risco para perda auditiva. Resultados: Com o protocolo usado, as respostas dos PEAC foram detectadas em todos os indivíduos em alta intensidade e limiares. Os limiares médios foram 24,8 ± 10,4 dBNA, 25 ± 9,0 dBNA, 28 ± 7,8 dBNA e 29,4 ± 6,6 dBNA para 500, 1000, 2000 e 4000 Hz, respectivamente. Conclusão: Foram obtidas respostas confiáveis na avaliação dos potenciais auditivos corticais em recém-nascidos com um dispositivo para detecção de resposta automática.

Wideband acoustic absorbance in children with Down syndrome / Absorvância acústica de banda larga em crianças com síndrome de Down

Abstract Introduction: Tympanometry is currently the most frequently used tool for assessing the status of the middle ear, commonly assessed using a single 226 Hz tone. However, the use of the Acoustic Immittance Measures with a wideband stimulus is a promising high-resolution evaluation, especially in individuals known to have middle ear alterations, such as Down syndrome patients. Objective: The aim of this study was to analyze the acoustic absorbance measurements in children with Down syndrome. Methods: Cross-sectional study, approved by the institution's ethics committee. Data were collected from 30 children, with a mean age of 8.4 years, 15 with Down syndrome (DS-study group) and 15 children with typical development and no hearing complaints (control group). Energy absorbance was measured at frequencies of 226-8000 Hz at ambient pressure and at peak pressure as a function of frequency using TITAN equipment. Statistical analysis was performed using the established level of statistical significance of 5%. Results: With the 226 Hz probe tone, 30 ears of the control group and 22 of the study group exhibited Type A tympanograms, whereas Type B was observed in eight children in the study group. The mean acoustic absorbance ratio of the study group was lower than that of the control group at frequencies centered at 2520 Hz (p = 0.008) for those with normal tympanometry results, and 226-4000 Hz (p < 0.03) for those with a Type B tympanometry curve. Conclusion: The low energy absorption in the presence of normal tympanograms in children with Down syndrome may suggest middle ear abnormalities.

Resumo Introdução: A timpanometria é a ferramenta mais usada para avaliar o status da orelha média, comumente avaliada por meio de uma única frequência com o tom de 226 Hz. No entanto, o uso da medida de imitância acústica com estímulo de banda larga é uma avaliação de alta resolução promissora, especialmente em pacientes conhecidos por frequentemente apresentar alterações da orelha média, como na síndrome de Down. Objetivo: Analisar as medidas de absorvância acústica em crianças com síndrome de Down. Método: Estudo transversal, aprovado pelo comitê de ética da instituição. Foram coletados dados de 30 crianças, com idade média de 8,4 anos, sendo 15 com síndrome de Down (SD-grupo de estudo) e 15 crianças desenvolvimento típico e sem queixas auditivas (grupo controle). A absorvância de energia foi medida nas frequências de 226-8.000 Hz à pressão ambiente e no pico de pressão em função da frequência, usou-se o equipamento Titan. A análise estatística foi feita com o nível de significância estatística adotado de 5%. Resultados: Com o tom de sonda de 226 Hz foram observadas 30 orelhas do grupo controle e 22 do grupo estudo com timpanometria Tipo A e o Tipo B foi observado apenas em oito crianças do grupo estudo. A razão média de absorvância acústica do grupo estudo foi menor do que a do controle nas frequências centradas em 2.520 Hz (p = 0,008) para aqueles com resultados timpanométricos normais e de 226-4.000 Hz (p < 0,03) para aqueles com curva timpanométrica Tipo B. Conclusão: A baixa absorção de energia na presença de timpanogramas normais nas crianças com síndrome de Down pode sugerir anormalidades na orelha média.

Wideband acoustic absorbance in children with Down syndrome.

INTRODUCTION: Tympanometry is currently the most frequently used tool for assessing the status of the middle ear, commonly assessed using a single 226Hz tone. However, the use of the Acoustic Immittance Measures with a wideband stimulus is a promising high-resolution evaluation, especially in individuals known to have middle ear alterations, such as Down syndrome patients. OBJECTIVE: The aim of this study was to analyze the acoustic absorbance measurements in children with Down syndrome. METHODS: Cross-sectional study, approved by the institution's ethics committee. Data were collected from 30 children, with a mean age of 8.4 years, 15 with Down syndrome (DS-study group) and 15 children with typical development and no hearing complaints (control group). Energy absorbance was measured at frequencies of 226-8000Hz at ambient pressure and at peak pressure as a function of frequency using TITAN equipment. Statistical analysis was performed using the established level of statistical significance of 5%. RESULTS: With the 226Hz probe tone, 30 ears of the control group and 22 of the study group exhibited Type A tympanograms, whereas Type B was observed in eight children in the study group. The mean acoustic absorbance ratio of the study group was lower than that of the control group at frequencies centered at 2520Hz (p=0.008) for those with normal tympanometry results, and 226-4000Hz (p<0.03) for those with a Type B tympanometry curve. CONCLUSION: The low energy absorption in the presence of normal tympanograms in children with Down syndrome may suggest middle ear abnormalities.