P1-N1-P2 Cortical Auditory Evoked Potentials in Chronic Unilateral Acquired Conductive Hearing Loss in Adults.

BACKGROUND:  Chronic unilateral hearing loss causes imbalanced auditory input to the brain that triggers cortical reorganization. The effect of sensorineural hearing loss on the central auditory system (CAS) has been thoroughly studied, while there is a paucity of research on the effect of conductive hearing loss (CHL). The aim of this study was to assess the P1-N1-P2 cortical auditory evoked response potential (CAEP) in adult individuals with chronic acquired unilateral CHL. METHODS:  This study included 108 participants of both genders: 54 patients with unilateral chronic CHL who were compared to well-matched 54 controls. All were subjected to history-taking, otologic examination, basic audiological evaluation, and bone conduction N1-P2 CAEP. RESULTS:  The affected ears of the cases showed highly statistically significant shorter CAEPs N1, P2, N1-P2 latencies but not P1, and showed highly statistically significant larger N1, P2, N1P2, amplitude than the control group. Latencies decreased and amplitudes increased as the degree of CHL increased, but were not affected by patients' age, side, or duration of the CHL. Cases with tinnitus had statistically significant and worse results than those without tinnitus. CONCLUSION:  Unilateral chronic CHL might enhance neurocortical plasticity, with greater changes occurring at greater degrees of the CHL.

The Merits of Bilateral Application of Middle Ear Implants in Patients With Bilateral Conductive and/or Mixed Hearing Loss.

This study investigated sound localization abilities in patients with bilateral conductive and/or mixed hearing loss (BCHL) when listening with either one or two middle ear implants (MEIs). Sound localization was measured by asking patients to point as quickly and accurately as possible with a head-mounted LED in the perceived sound direction. Loudspeakers, positioned around the listener within a range of +73°/-73° in the horizontal plane, were not visible to the patients. Broadband (500 Hz-20 kHz) noise bursts (150 ms), roved over a 20-dB range in 10 dB steps was presented. MEIs stimulate the ipsilateral cochlea only and therefore the localization response was not affected by crosstalk. Sound localization was better with bilateral MEIs compared with the unilateral left and unilateral right conditions. Good sound localization performance was found in the bilaterally aided hearing condition in four patients. In two patients, localization abilities equaled normal hearing performance. Interestingly, in the unaided condition, when both devices were turned off, subjects could still localize the stimuli presented at the highest sound level. Comparison with data of patients implanted bilaterally with bone-conduction devices, demonstrated that localization abilities with MEIs were superior. The measurements demonstrate that patients with BCHL, using remnant binaural cues in the unaided condition, are able to process binaural cues when listening with bilateral MEIs. We conclude that implantation with two MEIs, each stimulating only the ipsilateral cochlea, without crosstalk to the contralateral cochlea, can result in good sound localization abilities, and that this topic needs further investigation.

Bone mineral density of the incus body and long process in patients with chronic otitis media and its relationship with functional outcome in type II tympanoplasty.

BACKGROUND: Inflammatory conditions such as chronic otitis media (COM) can cause irreversible impairments in the microarchitecture and functions of the incus, which subsequently leads to conductive hearing loss. OBJECTIVES: To investigate bone mineral density (BMD) of the incus body (IB) and long process (ILP) on preoperative temporal CT in COM patients with and without incudo-stapedial joint discontinuity (ISJD), and also to determine the association between BMD values and the postoperative air-bone gap (ABG) in the ISJD group. MATERIAL AND METHODS: The mean IB density (IBD)/occipital bone density (OBD) and ILP density (ILPD)/OBD values were compared between the patients with and without ISJD. The correlation between ABG gain and preoperative incus density values was assessed in the ISJD group. RESULTS: The mean IBD/OBD and ILPD/OBD values were significantly higher in patients with intact ISJ. There was a moderate positive correlation between postoperative ABG gain and ILPD/OBD values in the ISJD group. CONCLUSION AND SIGNIFICANCE: The decrease in BMD of the incus may involve ILP as well as IB in patients with ISJD caused by ILP lysis in COM. A higher preoperative ILPD/OBD was correlated with a higher postoperative ABG gain in COM patients with ISJD.

Binaural hearing in monaural conductive or mixed hearing loss fitted with unilateral Bonebridge.

Objective: To determine the benefits of binaural hearing rehabilitation in patients with monaural conductive or mixed hearing loss treated with a unilateral bone conduction implant (BCI). Methods: This monocentric study includes 7 patients with monaural conductive or mixed hearing loss who underwent surgical implantation of a unilateral BCI (Bonebridge, Med-El). An ITA Matrix test was performed by each patient included in the study - without and with the BCI and in three different settings - to determine the summation effect, squelch effect and head shadow effect. Subjective hearing benefits were assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. Results: The difference in signal to noise ratio of patients without and with BCI was 0.79 dB in the summation setting (p < 0.05), 4.62 dB in the head shadow setting (p < 0.05) and 1.53 dB (p = 0.063) in the squelch setting. The APHAB questionnaire revealed a subjective discomfort in the presence of unexpected sounds in patients using a unilateral BCI (aversiveness score) compared to the same environmental situations without BCI, with a mean discomfort score of 69.00% (SD ± 21.24%) with monaural BCI versus 25.67% (SD ± 16.70%) without BCI (difference: -43.33%, p < 0.05). In terms of global score, patients wearing a unilateral Bonebridge implant did not show any significant differences compared to those without hearing aid (difference: -4.00%, p = 0.310). Conclusions: Our study shows that the use of a unilateral BCI in patients affected by monaural conductive or mixed hearing loss can improve speech perception under noise conditions due to the summation effect and to the decrease of the head shadow effect. However, since monaural BCIs might lead to discomfort under noise conditions in some subjects, a pre-operative assessment of the possible individual benefit of a monaural BCI should be carried out in patients affected by unilateral conductive or mixed hearing loss in order to investigate the possible additional effect of the fitting of hearing aids.

A Large-Scale Study of the Relationship Between Degree and Type of Hearing Loss and Recognition of Speech in Quiet and Noise.

OBJECTIVES: Understanding speech in noise (SIN) is the dominant complaint of individuals with hearing loss. For decades, the default test of speech perception in routine audiologic assessment has been monosyllabic word recognition in quiet (WRQ), which does not directly address patient concerns, leading some to advocate that measures of SIN should be integrated into routine practice. However, very little is known with regard to how SIN abilities are affected by different types of hearing loss. Here, we examine performance on clinical measures of WRQ and SIN in a large patient base consisting of a variety of hearing loss types, including conductive (CHL), mixed (MHL), and sensorineural (SNHL) losses. DESIGN: In a retrospective study, we examined data from 5593 patients (51% female) who underwent audiometric assessment at the Stanford Ear Institute. All individuals completed pure-tone audiometry, and speech perception testing of monaural WRQ, and monaural QuickSIN. Patient ages ranged from 18 to 104 years (average = 57). The average age in years for the different classifications of hearing loss was 51.1 (NH), 48.5 (CHL), 64.2 (MHL), and 68.5 (SNHL), respectively. Generalized linear mixed-effect models and quartile regression were used to determine the relationship between hearing loss type and severity for the different speech-recognition outcome measures. RESULTS: Patients with CHL had similar performance to patients with normal hearing on both WRQ and QuickSIN, regardless of the hearing loss severity. In patients with MHL or SNHL, WRQ scores remained largely excellent with increasing hearing loss until the loss was moderately severe or worse. In contrast, QuickSIN signal to noise ratio (SNR) losses showed an orderly systematic decrease as the degree of hearing loss became more severe. This effect scaled with the data, with threshold-QuickSIN relationships absent for CHL, and becoming increasingly stronger for MHL and strongest in patients with SNHL. However, the variability in these data suggests that only 57% of the variance in WRQ scores, and 50% of the variance in QuickSIN SNR losses, could be accounted for by the audiometric thresholds. Patients who would not be differentiated by WRQ scores are shown to be potentially differentiable by SIN scores. CONCLUSIONS: In this data set, conductive hearing loss had little effect on WRQ scores or QuickSIN SNR losses. However, for patients with MHL or SNHL, speech perception abilities decreased as the severity of the hearing loss increased. In these data, QuickSIN SNR losses showed deficits in performance with degrees of hearing loss that yielded largely excellent WRQ scores. However, the considerable variability in the data suggests that even after classifying patients according to their type of hearing loss, hearing thresholds only account for a portion of the variance in speech perception abilities, particularly in noise. These results are consistent with the idea that variables such as cochlear health and aging add explanatory power over audibility alone.

Contralateral occlusion test: The effect of external ear canal occlusion on predicting conductive hearing loss / Prueba de oclusión contralateral: el efecto de la oclusión del conducto auditivo externo en la predicción del grado de hipoacusia de transmisión

INTRODUCTION AND OBJECTIVES: The contralateral occlusion test (COT) has the potential to allow the quantitative evaluation of unilateral conductive hearing loss. The purpose of this study was to determine the accuracy of the test in predicting the degree of hearing loss. MATERIALS AND METHODS: Fifty-three subjects with unilateral conductive hearing loss were recruited from an otolaryngology department of a tertiary hospital. The COT was performed using 128, 256, 512, 1024 and 2048Hz tuning forks with the non-affected ear canal totally occluded to determine lateralization. Pure-tone audiometry was performed to establish the presence and degree of the air-bone gap (ABG) and the pure-tone average (PTA). The tuning fork responses were correlated with the ABG and the PTA to determine their accuracy. RESULTS: The COT showed a better association between hearing loss and the lateralization response using the 512Hz tuning fork (p = 0.001). The sensitivity of the 512 Hz fork in detecting a PTA of at least 35.6 dB was 94.6% and the specificity was 75.0% for a positive predictive value of 89.7% and a negative predictive value of 85.7%, assuming a pretest prevalence of 69.8%. CONCLUSIONS: The overall accuracy of the COT in predicting the degree of unilateral conductive hearing loss was significant. The COT had significant power in one direction: if lateralization to the affected ear occurred, it was almost certain evidence of a moderate or severe conductive hearing loss

INTRODUCCIÓN Y OBJETIVOS: La prueba de oclusión contralateral (POC) nos permite realizar una evaluación cuantitativa de la hipoacusia transmisiva unilateral. El objetivo de este estudio consistió en determinar la exactitud de esta prueba para predecir el grado de pérdida auditiva. MATERIAL Y MÉTODOS: Fueron reclutados 53 pacientes con hipoacusia unilateral transmisiva en el departamento de otorrinolaringología de un hospital terciario. La POC fue realizada utilizando diapasones de 128, 256, 512, 1024 y 2048 Hz, con el conducto auditivo del oído sano totalmente ocluido, para determinar la lateralización. Se realizó una audiometría de tonos puros para establecer la presencia y grado del umbral diferencial de audición (UDA) y del Promedio de Tonos Puros (PTA). La respuesta con los diapasones fue correlacionada con el UDA y la PTA para determinar su exactitud. RESULTADOS: La POC demostró una mejor asociación entre la pérdida auditiva y la lateralización, usando el diapasón de 512 Hz (p = 0,001). La sensibilidad del diapasón de 512 Hz en detectar la PTA, de al menos 35,6dB, fue del 94,6% y la especificidad del 75%, y un valor predictivo positivo de 89,7% y valor predictivo negativo de 85,7%, asumiendo la prevalencia pre-test del 69,8%. CONCLUSIONES: La precisión general de la POC en predecir el grado de pérdida auditiva transmisiva unilateral fue significativa. La POC puede ser utilizada de forma significativa en los casos de lateralización al oído afecto, ya que existe una evidencia casi segura de una pérdida auditiva transmisiva moderada o severa

Contralateral Occlusion Test (COT): the effect of external ear canal occlusion with aging / Teste de Oclusão Contralateral (TOC): o efeito da oclusão do canal auditivo externo com a idade

ABSTRACT Purpose This study aimed to evaluate the effects of complete external ear canal occlusion on hearing thresholds with aging. The goal was to decide which tuning fork is more appropriate to use for the contralateral occlusion test (COT), in individuals of different ages. Methods Forty-two normal hearing subjects between 21 and 67 years were divided into three age groups (20-30 years, 40-50 years, and 60-70 years). Participants underwent sound field audiometry tests with warble tones, with and without ear canal occlusion. Each ear was tested with the standard frequencies (250, 500, 1000, and 2000 Hz). The contralateral ear was suppressed by masking. Results Hearing thresholds showed an increase as the frequency increased from 20.85 dB (250 Hz, 20-30 years group) to 48 dB (2000 Hz, 60-70 years group). The threshold differences between occlusion and no occlusion conditions were statistically significant and increased ranging from 11.1 dB (250 Hz, 20-30 years group) to 32 dB (2000 Hz, 20-30 years group). We found statistically significant differences for the three age groups and for all evaluations except to 500 Hz difference and average difference. The mean hearing loss produced by occlusion at 500 Hz was approximately 19 dB. We found no statistically significant differences between right and left ears and gender for all measurements. Conclusion We conclude that the use of the 512 Hz tuning fork is the most suitable for COT, and its use may allow clinicians to distinguish mild from moderate unilateral conductive hearing loss.

RESUMO Objetivo O objetivo deste estudo foi avaliar o efeito da oclusão completa do canal auditivo externo nos limiares auditivos, em indivíduos de idades distintas, para apurar qual o diapasão mais adequado na realização do teste de oclusão contralateral (TOC). Método 42 indivíduos normo-ouvintes (21-67 anos) foram divididos em três grupos etários (20-30, 40-50 e 60-70 anos). Os participantes foram avaliados com testes de audiometria tonal liminar em campo livre, com e sem oclusão completa do canal auditivo externo. Cada ouvido foi testado para as frequências 250, 500, 1000 e 2000 Hz. No ouvido contralateral, foi realizado mascaramento, para evitar a ocorrência de audição contralateral. Resultados Verificou-se aumento dos limiares auditivos, diretamente proporcional ao aumento da frequência (desde 20.85 até 48 dB). A diferença nos limiares auditivos entre a condição de oclusão e de não oclusão foi estatisticamente significativa em todas as frequências e aumentou de forma diretamente proporcional com a frequência (desde 11.1 até 32 dB). Foram também encontradas diferenças estatisticamente significativas para os três grupos etários, em todos os parâmetros, exceto na diferença a 500 Hz e na diferença total média. A perda auditiva média resultante da oclusão aos 500 Hz foi de 19 dB. Não se encontraram diferenças estatisticamente significativas entre o ouvido direito e o esquerdo, e entre o gênero. Conclusão A utilização do diapasão de 512 Hz é a mais adequada para o TOC. A sua utilização pode permitir aos clínicos, em ambiente de consulta e de forma rápida, a distinção entre perda condutiva de grau leve a moderada.

Effect of conductive hearing loss on central auditory function / Efeito da perda auditiva condutiva na função auditiva central

Abstract Introduction: It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. Objective: This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. Methods: During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. Results: The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p = 0.004; left: p < 0.001). Individuals with CHL had significantly lower correct responses than individuals with normal hearing for both sides (p < 0.001). No correlation was found between GIN performance and degree of hearing loss in either group (p > 0.05). Conclusion: The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended.

Resumo Introdução: Já foi demonstrado que a perda auditiva condutiva (PAC), em longo prazo, pode influenciar na detecção precisa das características temporais dos sinais acústicos ou do processamento auditivo temporal (PAT). Pode-se argumentar que o PAT pode ser o componente subjacente de muitos recursos do processamento auditivo central, como a compreensão da fala ou localização do som. Pouco se sabe sobre as consequências da PAC nos aspectos temporais do processamento auditivo central. Objetivo: Este estudo foi projetado para avaliar a capacidade de processamento auditivo temporal em indivíduos com PAC crônica. Método: Durante este estudo transversal analítico, 52 pacientes com PAC crônica leve a moderada e 52 indivíduos com audição normal (controle), entre 18 e 45 anos, foram recrutados. Para avaliar o processamento auditivo temporal, foi usado o teste de resolução temporal Gaps-in-Noise (GIN). Os resultados obtidos para cada orelha foram analisados com base no limiar de percepção da quebra de continuidade (gap) e na porcentagem de respostas corretas. Resultados: A média dos limiares no GIN foi significativamente menor para o grupo controle do que para o grupo PAC em ambas as orelhas (direita: p = 0,004; esquerda: p < 0,001). Os indivíduos com PAC apresentaram respostas corretas significativamente mais baixas do que os indivíduos com audição normal em ambas as orelhas (p < 0,001). Não houve correlação entre o desempenho no GIN e o grau de perda auditiva em ambos os grupos (p > 0,05). Conclusão: Os resultados sugerem uma redução da capacidade de processamento auditivo temporal em adultos com PAC comparados com indivíduos que apresentam audição normal. Portanto, o desenvolvimento de um protocolo clínico para avaliar o processamento auditivo temporal nessa população é recomendado.

Achados audiológicos e eletrofisiológicos de indivíduos com a síndrome G/BBB / Auditory findings and electrophysiologics in individuals with G/BBB syndrome

A síndrome G/BBB é uma condição rara, caracterizada por hipertelorismo, fissura de lábio e palato e hipospádia. Não foram encontrados trabalhos sobre a audição em indivíduos com esta síndrome. OBJETIVO: Investigar a função auditiva em pacientes com síndrome G/BBB quanto à ocorrência ou não de perda auditiva e a condução nervosa auditiva periférica e central. MATERIAL E MÉTODO: Catorze pacientes de 7 a 34 anos, do gênero masculino, com a síndrome G/BBB, foram avaliados por meio de otoscopia, audiometria, timpanometria e potenciais evocados auditivos de tronco encefálico (PEATE). Forma de Estudo: Estudo de série clínico prospectivo. RESULTADOS: Limiares audiométricos normais em 12 (66,7 por cento) pacientes da amostra e alterados em dois (33,3 por cento), sendo um com perda condutiva e um neurossensorial. Quanto ao PEATE, foram encontrados: latências absolutas da onda I normais em todos os pacientes, aumento das latências absolutas da onda III e V em dois e seis pacientes respectivamente; latências interpicos I-III, III-V e I-V aumentadas em quatro, três e oito pacientes, respectivamente. CONCLUSÃO: Perdas auditivas periféricas podem ocorrer na síndrome G/BBB. Há evidências de comprometimento das vias auditivas centrais em nível do tronco encefálico. Estudos com exames de imagem são necessários para maior clareza dos achados clínicos.

The G/BBB syndrome is a rare condition characterized by hypertelorism, cleft lip and palate, and hypospadias. No studies were found on the hearing of individuals with this syndrome. AIM: To investigate the auditory function in patients with G/BBB syndrome, such as the occurrence of hearing loss, and central and peripheral auditory nerve conduction. METHODS: Fourteen male patients aged 7-34 years with the G/BBB syndrome were assessed by otoscopy, audiometry, tympanometry and evoked auditory brainstem response (ABR). Model: A retrospective clinical series study. RESULTS: Audiometric thresholds were normal in 12 (66.7 percent) of the sample and altered in two (33.3 percent), one with conductive and one with sensorineural loss. ABR resuts were: all patients had normal absolute wave I latencies; absolute wave III and V latencies were increased in two and six patients, respectively; interpeak latencies I-III, IV and V interpeak latencies were increased in four, three and eight patients respectively. CONCLUSION: Hearing loss can occur in the G/BBB syndrome. There is evidence of central auditory pathway involvement in the brainstem. Imaging studies are needed to clarify the clinical findings.

Estudo audiológico e genético de lactentes de alto risco / Audiological and genetics studies in high-risk infants

A audição é um dos principais meios de contato do indivíduo com o mundo externo, desempenhando papel fundamental na integração com a sociedade. OBJETIVO: Analisar os resultados obtidos na avaliação audiológica, otorrinolaringológica e genética de lactentes de alto risco que falharam na triagem auditiva neonatal. MATERIAL E MÉTODO: Estudo clínico e experimental. Foram avaliados 38 lactentes, entre 1 e 6 meses de idade cronológica. Os procedimentos utilizados foram: anamnese, imitanciometria, Potencial Evocado Auditivo de Tronco Encefálico, Emissões Otoacústicas por Transiente e avaliação otorrinolaringológica. O estudo genético foi realizado a partir da extração de DNA da mucosa bucal utilizando o método de protocolo adaptado no Laboratório de Genética Humana do CBMEG/UNICAMP. RESULTADO: Não houve diferença estatisticamente significante entre neonatos com audição normal e perda auditiva e as variáveis gênero e número de indicadores de risco. Quanto à idade gestacional, neonatos a termo foram mais afetados. A perda auditiva esteve presente em 58 por cento da amostra, sendo do tipo condutiva em 31,5 por cento, e neurossensorial em 28,9 por cento dos casos. Não foram encontradas as mutações genéticas mais comumente observadas em casos com etiologia genética. CONCLUSÃO: A perda auditiva foi diagnosticada na maioria dos lactentes de risco com provável etiologia ambiental.

Hearing is one of the main ways with which one person can contact the external world; it plays a key role in their integration with society. AIM: The objective of this study was to analyze the results of the hearing, medical and genetic evaluation of high-risk infants who failed the newborn hearing screening. MATERIALS AND METHODS: Clinical and experimental study. We assessed thirty-eight neonates, with ages between one and six months. The infants underwent the following procedures: medical interview; immittance testing; Brainstem Auditory Evoked Potential; Transient Evoked Otoacoustic Emission and otorhinolaryngological evaluation. DNA extraction from the oral mucosa was performed for genetic studies using the protocol method adapted from the Human Genetics Lab of the CBMEG/UNICAMP. RESULTS: Regarding gender and presence of risk factors, significant statistically differences were not found in normal hearing infants and in those with hearing loss. Concerning gestational age, term infants were more affected by hearing loss. Hearing loss was identified in 58 percent of the sample, conduction hearing loss represented 31.5 percent (12/38) and neurossensory 28.9 percent of cases. There were none of the genetic mutations most commonly seen in cases with a genetic etiology. CONCLUSION: Hearing loss was identified in the majority of High-risk infants.

Resolução temporal de crianças: comparação entre audição normal, perda auditiva condutiva e distúrbio do processamento auditivo / Temporal resolution in children: comparing normal hearing, conductive hearing loss and auditory processing disorder

A resolução temporal é essencial na percepção acústica da fala, podendo estar alterada nos distúrbios auditivos gerando prejuízos no desenvolvimento da linguagem. OBJETIVO: Comparar a resolução temporal de crianças com audição normal, perda auditiva condutiva e distúrbios do processamento auditivo. CASUÍSTICA E MÉTODO: A amostra foi de 31 crianças de 07 a 10 anos, divididas em três grupos: G1: 12 com audição normal, G2: sete com perda auditiva condutiva e G3: 12 com distúrbio do processamento auditivo. Os procedimentos de seleção foram: questionário aos responsáveis, avaliação audiológica e do processamento auditivo. O procedimento de pesquisa foi o teste de detecção de intervalos no silêncio realizado a 50 dB NS acima da média de 500, 1000 e 2000Hz na condição binaural em 500, 1000, 2000 e 4000Hz. Na análise dos dados foi utilizado o Teste de Wilcoxon, com nível de significância de 1%. RESULTADO: Observou-se que houve diferença entre os G1 e G2 e entre os G1 e G3 em todas as freqüências. Por outro lado, esta diferença não foi observada entre os G2 e G3. CONCLUSÃO A perda auditiva condutiva e o distúrbio do processamento auditivo têm influência no limiar de detecção de intervalos.

Temporal resolution is essential to speech acoustic perception. It may be altered in subjects with auditory disorders, thus impairing the development of spoken and written language. AIM: The goal was to compare temporal resolution of children with normal hearing, with those bearing conductive hearing loss and auditory processing disorders. MATERIALS AND METHODS: The sample had 31 children, between 7 and 10 years of age, broken down into three groups: G1: 12 subjects with normal hearing; G2: 7 with conductive hearing loss and G3: 12 subjects with auditory processing disorders. This study was clinical and experimental. Selection procedures were: a questionnaire to be answered by the parents/guardians, audiologic and hearing processing evaluation. The study procedure was the test to detect breaks in silence at 50 dB HL above the mean values of 500, 1000 and 2000 Hz in both ears in 500, 1000, 2000 and 4000 Hz. To analyze the data we used the Wilcoxon Test with a 1% significance level. RESULTS: We noticed a difference between G1 and G2 and between G1 and G3 in all the frequencies. On the other hand, this difference was not seen between G2 and G3. CONCLUSION: conductive hearing loss and auditory processing disorders can impact break detection thresholds.

Fisiología de la estimulación sonora por vía ósea y la importancia de la transmisión de las frecuencias agudas por vía ósea / Physiology of bone conduction acoustic stimulation and the importance of high-frequency bone conduction

Se considera que el fenómeno de la transmisión de los sonidos por vía ósea no es tan simple como que únicamente la vibración de los huesos del cráneo pone en movimiento los líquidos laberínticos. Se conoce que esta energía mecánica se reparte en el oído externo, el medio y el interno, y es difícil precisar cuál es la contribución de cada una de estas partes al total de la conducción. La inercia de los fluidos cocleares es la contribución más importante a la audición por vía ósea, la inercia de los huesecillos contribuye en la conducción de las frecuencias medias, mientras que la compresión de las paredes cocleares influye en la conducción de las frecuencias agudas. (AU)

The phenomenon of bone-conducted sound transmission involves more than just vibration of the skull bones to induce movement of the labyrinthine fluid. This mechanical energy is known to be distributed through the outer, middle and inner ear and identifying the precise contribution of each of these parts to total conductance is difficult. Cochlear fluid inertia is the most important contributing factor to bone-conduction hearing, inertia of the ossicles plays a role in medium-frequency conduction, while cochlear wall compression plays a role in high frequencies (AU)

Fisiopatologia da surdez de conduçäo / Physiopathology conductive deafness

A fisiopatologia da surdez de conduçäo é explicada pelos diversos tipos de alteraçöes que podem ocorrer no mecanismo tímpano-ossicular. O tema avulta em importância porque a surdez de conduçäo representa deficiência auditiva que pode ser recuperada por cirurgia na grande maioria dos casos. O conhecimento da fisiologia da audiçäo e os recursos empregados no exame otológico permiten diagnósticos da causa da surdez e a aplicaçäo de métodos capazes de promover, com sucesso, a transmissäo sonora dos pacientes