A perda auditiva no idoso acarreta em dificuldade na percepção da fala. O teste comumente utilizado na logoaudiometria é a pesquisa do índice de reconhecimento de fala máximo (IR-Max) em uma única intensidade de apresentação da fala. Entretanto, o procedimento mais adequado seria a realização do teste em diversas intensidades, visto que o índice de acerto depende da intensidade da fala no momento do teste e está relacionado com o grau e configuração da perda auditiva. A imprecisão na obtenção do IR-Max poderá gerar uma hipótese diagnóstica errônea e o insucesso no processo de intervenção na perda auditiva. Objetivo: Verificar a interferência do nível de apresentação da fala, no teste de reconhecimento de fala, em idosos com perda auditiva sensorioneural com diferentes configurações audiométricas. Métodos: Participaram 64 idosos, 120 orelhas (61 do gênero feminino e 59 do gênero masculino), idade entre 60 e 88 anos, divididos em grupos: G1- composto por 23 orelhas com configuração horizontal, G2- 55 orelhas com configuração descendente, G3- 42 orelhas com configuração abrupta. Os critérios de inclusão foram: perda auditiva sensorioneural de grau leve a severo, não usuário de aparelho de amplificação sonora individual (AASI), ou com tempo de uso inferior a dois meses, e ausência de alterações cognitivas. Foram realizados os seguintes procedimentos: pesquisas do limiar de reconhecimento de fala (LRF), do índice de reconhecimento de fala (IRF) em diversas intensidades e do nível de máximo conforto (MCL) e desconforto (UCL) para a fala. Para tal, foram utilizadas listas com 11 monossílabos, para diminuir a duração do teste. A análise estatística foi composta pelo teste Análise de Variância (ANOVA) e teste de Tukey. Resultados: A configuração descendente foi a de maior ocorrência. Indivíduos com configuração horizontal apresentaram índice médio de acerto mais elevado de reconhecimento de fala. Ao considerar o total avaliado, 27,27% dos indivíduos com configuração horizontal revelaram o IR-Max no MCL, assim como 38,18% com configuração descendente e 26,19% com configuração abrupta. O IR-Max foi encontrado no UCL, em 40,90% dos indivíduos com configuração horizontal, 45,45% com configuração descendente e 28,20% com configuração abrupta. Respectivamente, o maior e o menor índice médio de acerto foram encontrados em: G1- 30 e 40 dBNS; G2- 50 e 10 dBNS; G3- 45 e 10 dBNS. Não há uma única intensidade de fala a ser utilizada em todos os tipos de configurações audiométricas, entretanto, os níveis de sensação que identificaram os maiores índices médios de acerto foram: G1- 20 a 30 dBNS, G2- 20 a 50 dBNS; G3- 45 dBNS. O MCL e o UCL-5 dB para a fala não foram eficazes para determinar o IR-Max. Conclusões: O nível de apresentação teve influência no desempenho no reconhecimento de fala para monossílabos em idosos com perda auditiva sensorioneural em todas as configurações audiométricas. A perda auditiva de grau moderado e a configuração audiométrica descendente foram mais frequentes nessa população, seguida da abrupta e horizontal. / Hearing loss in elderly causes difficulty in speech perception. The test commonly used in speech audiometry is the search for the maximum speech recognition score (PB-Max) in a single presentation intensity of speech. However, the most adequate procedure would be the test at multiple intensities considering that the correct level depends on the intensity of the speech at the moment of the test and is related to the degree and configuration of hearing loss. The imprecision in obtaining the PB-Max can produce an erroneous diagnostic hypothesis and failure in the intervention process in hearing loss. Purpose: To verify the interference of the level of speech presentation, through the speech recognition test, in elderly patients with sensorineural hearing loss with different audiometric configurations. Methods: Participants were 64 elderly, 120 ears (61 females and 59 males), ages ranging from 60 to 88, divided into three groups: G1- comprising 23 ears with flat configuration, G2- 55 ears with gradually sloping, G3- 42 ears with steeply sloping configuration. The criteria of inclusion of individuals were: sensorineural hearing loss from mild to severe degree, no hearing aid users, or period of use lower than two months, and absence of any cognitive impairment. The following procedures were performed: speech recognition threshold (SRT), word recognition scores at multiple intensities, most comfortable loudness level (MCL) and uncomfortable loudness level (UCL) using speech stimuli. For the procedure above, lists of 11 monosyllabic words were presented, in order for the test duration to be reduced. Statistical analysis was made by the test Analysis of Variance (ANOVA) and Tukey\'s test. Results: The gradually sloping configuration was the most common. Subjects with flat configuration showed higher correct mean level in speech recognition. Considering the total ears assessed, 27.27% of subjects with flat configuration revealed the PB-max in MCL, as well as, 38.18% with gradually sloping and 26.19% with steeply sloping configuration. The PB-max was found in the UCL, in 40.90% of the subjects with a flat configuration, 45.45% with gradually sloping configuration and 28.20% with steeply sloping configuration. Respectively, the highest and the lowest correct mean indexes were found: G1- 30 and 40 dB SL; G2- 50 and 10 dB SL; G3- 45 and 10 dB SL. There is not a single speech intensity to be used in all types of audiometric configurations, however, the sensation levels that identified the correct mean levels were found: G1 - 20-30 dB SL, G2 - 20-50 dB SL; G3 - 45 dB SL. The MCL and UCL-5 dB using speech stimuli, were not effective to determine the PB-Max. Conclusion: The presentation level influenced the performance in speech recognition for monosyllables in elderly patients with sensorineural hearing loss in all audiometric configurations. Moderate hearing loss and gradually sloping configuration were more frequent in this population, followed by steeply sloping and flat configuration.

Os objetivos do estudo consistiram em verificar o impacto da infecção congênita por CMV ao nascer e avaliar potenciais preditores prognósticos de anormalidades tardias em uma coorte de criança s com esta infecção. Métodos: Por meio de uma triagem neonatal, 66 de 11.957 crianças foram identificadas como portadoras de infecção congênita por CMV. Todas as crianças infectadas sintomáticas e assintomáticas foram avaliadas ao nascimento por meio de exame físico detalhado, avaliação auditiva, fundoscopia ocular, neurossonografia transfontanelar (NTF) realizada por neurorradiologista infantil e quando alterada, foram submetidas à ressonância magnética de encéfalo (RMc). Análise de regressão logística foi realizada para verificar a associação de potenciais fatores de risco para ocorrência de surdez neurossensorial relacionada ao CMV e/ou presença de achados anormais em NTF e/ou RMc. A análise da Curva ROC foi utilizada para avaliar a associação da carga do DNA do CMV expresso em log10, com a presença de sintomas ao nascer, achados anormais em NTF e/ou RMc e ocorrência de surdez neurosensorial. Resultados: Em 66 crianças infectadas, os sinais clínicos sugestivos de infecção congênita ao nascer foram observados em 8/66 (12,12%; IC95%: 5,74-23,03), sendo considerados sintomáticos. As 58 crianças restantes foram considerados assintomáticos. A surdez neurossensorial foi observada em 8/66 (12,12%; IC95%: 5,74-23,03%) das crianças. Destas, 4/58 (6,9%; IC95%: 2,23- 17,54%) e 4/8 (50%; IC95%: 17,44-82,55%) crianças eram assintomáticas e sintomáticas, respectivamente. Achados de NTF e/ou RMc sugestivas de infecção congênita foram observadas em 7 de 8 crianças sintomáticas (87,5%; IC95%: 46,67-99,34%). Dentre as 58 assintomáticas, 53 (92,4%) completaram todas as avaliações e destas 29/52 apresentaram alterações sugestivas de infecção congênita em NTF e/ou RMc (55,7%; IC95%: 41,41 - 69,27%). O achado mais comum foi a vasculopatia lenticuloestriada acompanhado ou não de cistos subpendimários (13/29: 43.3%). Outros achados anormais foram os cistos subpendimários como achado isolado (11/29: 37.9%), calcificação única ou periventricular com ou sem áreas de gliose (4/29: 13,8%) e ventriculomegalia (4/29: 13,8%). Análise de regressão logística mostrou que apenas a presença de sintomas clínicos ao nascer foi preditivo para a ocorrência de surdez neurossensorial. Achados de neuroimagens (NTF e/ou RMc) foram observados em 3 de 4 crianças assintomáticas (75%) enquanto 26 (54,2%) de 48 crianças sem surdez tinham avaliações normais de NTF e/ou RMc (p=0,42; RR:2,38: IC95%: 0,26-21,39). Nenhum dos outros fatores de risco foram independentemente associados com surdez. A presença de plaquetopenia e/ou níveis altos de gama glutamil transferase (?GT) foi associado com a presença de achados anormais em NTF e/ou RMc uma análise univariada. O poder discriminatório pela determinação do ponto de corte do valor da carga do DNA do CMV foi avaliada pela área abaixo da curva ROC (AUC) e não houve associação entre a carga viral e a ocorrência de surdez e/ou achados anormais de NTF e/ou RMc. Conclusões: Embora a triagem neonatal da infecção congênita por CMV permita identificar a maioria das crianças infectadas que são clinicamente assintomáticas ao nascer, uma proporção significante destas crianças poderá ser beneficiada por uma avaliação do sistema nervoso central através de NTF, uma vez que, achados anormais são muito frequentes. Embora não tenha sido possível determinar fatores independentemente preditivos de ocorrência de surdez neurossensorial, os achados de NTF podem ser potenciais fatores preditivos de anormalidades tardias em crianças assintomáticas. / The objectives of this study were to verify the impact of congenital cytomegalovirus (CMV) infection at birth and to evaluate potential prognostic predictors of late abnormalities in a cohort of children with this infection. Methods: By means of a CMV neonatal screening, 66 of 11.957 infants were identified as congenitally infected. Infants with and without clinical abnormalities detectable at birth underwent physical examination, cranial ultrasound performed by a paediatric radiologist and/or cranial magnetic resonance imaging, ocular fundoscopy, and hearing evaluation using evoked otoacoustic emissions and auditory brainstem response. Logistic regression analysis was carried out to verify the association between the risk factors for occurrence of hearing loss related to CMV and/ or abnormal cranial ultrasound findings. ROC curve was plotted using the log10 value of CMV DNA load to evaluate the association between viral load and clinical symptoms at birth, abnormal cranial ultrasound findings and hearing loss. Results: Of all 66 infected children, the clinical signs suggestive of congenital infection at birth were observed in 8/66 (12.12%; IC95%: 5.74- 23.03) symptomatic infants. Sensorineural hearing loss was observed in 8/66 (12,12%; IC95%: 5.74-23.03%) children. Of these, 4/58 (6,9%; IC95%: 2.23-17.54%) and 4/8 (50%; IC95%: 17,44-82.55%) children were asymptomatic and symptomatic, respectively. Cranial ultrasound findings suggestive of congenital infection were observed in 7 of the 8 symptomatic children (87.5%; IC95%: 46.67-99.34%). Among the 58 asymptomatic infants, 53 underwent complete evaluation and 29/52 had abnormal cranial ultrasound results (55,7%; IC95%: 41.41 - 69,27%). The most prevalent findings was lenticulostriate vasculopathy with subependymal pseudocysts present in 13 of the /29 (43.3%) infants with cranial ultrasound. Other abnormal findings were isolated subependymal pseudocysts (11/29: 37.9%); single or periventricular calcifications and/or gliosis (4/29: 13.8%); and ventriculomegaly (4/29: 13,8%). Logistic regression analysis showed that only the presence of clinical findings predicted the occurrence of hearing loss. Cranial ultrasound findings were observed in 3 of asymptomatic infants (75.0%) while 26 (54.2%) of 48 infants with no hearing loss had abnormal imaging features (p=0,42; RR:2,38: IC95%: 0,26-21,39). None of the other factors risk were independely associated with development of hearing loss. The presence of thrombocytopenia and/or high level of gamma-glutamyltranspeptidase (?GT) was associated with cranial ultrasound findings on univariated analysis. No discrimination power was achieved using the area under the ROC curve to verify the association between CMV DNA load in the urine of the infected children and the developing of hearing loss, presence of cranial ultrasound findings and clinical signs at birth. Conclusions: Although a neonatal screening of cCMV will identify the majority of infected infants who are clinically asymptomatic, a significant proportion of them could benefit from a central nervous system image evaluation, since abnormal findings are frequent. Althoug it was not possible to determine risk factors that are independently associated to development of sensorineural hearing loss, cranial ultrasound findings could be a potential prognostic markers of adverse outcomes of congenital CMV in asymptomatic infants.

Os objetivos do estudo consistiram em verificar o impacto da infecção congênita por CMV ao nascer e avaliar potenciais preditores prognósticos de anormalidades tardias em uma coorte de criança s com esta infecção. Métodos: Por meio de uma triagem neonatal, 66 de 11.957 crianças foram identificadas como portadoras de infecção congênita por CMV. Todas as crianças infectadas sintomáticas e assintomáticas foram avaliadas ao nascimento por meio de exame físico detalhado, avaliação auditiva, fundoscopia ocular, neurossonografia transfontanelar (NTF) realizada por neurorradiologista infantil e quando alterada, foram submetidas à ressonância magnética de encéfalo (RMc). Análise de regressão logística foi realizada para verificar a associação de potenciais fatores de risco para ocorrência de surdez neurossensorial relacionada ao CMV e/ou presença de achados anormais em NTF e/ou RMc. A análise da Curva ROC foi utilizada para avaliar a associação da carga do DNA do CMV expresso em log10, com a presença de sintomas ao nascer, achados anormais em NTF e/ou RMc e ocorrência de surdez neurosensorial. Resultados: Em 66 crianças infectadas, os sinais clínicos sugestivos de infecção congênita ao nascer foram observados em 8/66 (12,12%; IC95%: 5,74-23,03), sendo considerados sintomáticos. As 58 crianças restantes foram considerados assintomáticos. A surdez neurossensorial foi observada em 8/66 (12,12%; IC95%: 5,74-23,03%) das crianças. Destas, 4/58 (6,9%; IC95%: 2,23- 17,54%) e 4/8 (50%; IC95%: 17,44-82,55%) crianças eram assintomáticas e sintomáticas, respectivamente. Achados de NTF e/ou RMc sugestivas de infecção congênita foram observadas em 7 de 8 crianças sintomáticas (87,5%; IC95%: 46,67-99,34%). Dentre as 58 assintomáticas, 53 (92,4%) completaram todas as avaliações e destas 29/52 apresentaram alterações sugestivas de infecção congênita em NTF e/ou RMc (55,7%; IC95%: 41,41 - 69,27%). O achado mais comum foi a vasculopatia lenticuloestriada acompanhado ou não de cistos subpendimários (13/29: 43.3%). Outros achados anormais foram os cistos subpendimários como achado isolado (11/29: 37.9%), calcificação única ou periventricular com ou sem áreas de gliose (4/29: 13,8%) e ventriculomegalia (4/29: 13,8%). Análise de regressão logística mostrou que apenas a presença de sintomas clínicos ao nascer foi preditivo para a ocorrência de surdez neurossensorial. Achados de neuroimagens (NTF e/ou RMc) foram observados em 3 de 4 crianças assintomáticas (75%) enquanto 26 (54,2%) de 48 crianças sem surdez tinham avaliações normais de NTF e/ou RMc (p=0,42; RR:2,38: IC95%: 0,26-21,39). Nenhum dos outros fatores de risco foram independentemente associados com surdez. A presença de plaquetopenia e/ou níveis altos de gama glutamil transferase (?GT) foi associado com a presença de achados anormais em NTF e/ou RMc uma análise univariada. O poder discriminatório pela determinação do ponto de corte do valor da carga do DNA do CMV foi avaliada pela área abaixo da curva ROC (AUC) e não houve associação entre a carga viral e a ocorrência de surdez e/ou achados anormais de NTF e/ou RMc. Conclusões: Embora a triagem neonatal da infecção congênita por CMV permita identificar a maioria das crianças infectadas que são clinicamente assintomáticas ao nascer, uma proporção significante destas crianças poderá ser beneficiada por uma avaliação do sistema nervoso central através de NTF, uma vez que, achados anormais são muito frequentes. Embora não tenha sido possível determinar fatores independentemente preditivos de ocorrência de surdez neurossensorial, os achados de NTF podem ser potenciais fatores preditivos de anormalidades tardias em crianças assintomáticas. / The objectives of this study were to verify the impact of congenital cytomegalovirus (CMV) infection at birth and to evaluate potential prognostic predictors of late abnormalities in a cohort of children with this infection. Methods: By means of a CMV neonatal screening, 66 of 11.957 infants were identified as congenitally infected. Infants with and without clinical abnormalities detectable at birth underwent physical examination, cranial ultrasound performed by a paediatric radiologist and/or cranial magnetic resonance imaging, ocular fundoscopy, and hearing evaluation using evoked otoacoustic emissions and auditory brainstem response. Logistic regression analysis was carried out to verify the association between the risk factors for occurrence of hearing loss related to CMV and/ or abnormal cranial ultrasound findings. ROC curve was plotted using the log10 value of CMV DNA load to evaluate the association between viral load and clinical symptoms at birth, abnormal cranial ultrasound findings and hearing loss. Results: Of all 66 infected children, the clinical signs suggestive of congenital infection at birth were observed in 8/66 (12.12%; IC95%: 5.74- 23.03) symptomatic infants. Sensorineural hearing loss was observed in 8/66 (12,12%; IC95%: 5.74-23.03%) children. Of these, 4/58 (6,9%; IC95%: 2.23-17.54%) and 4/8 (50%; IC95%: 17,44-82.55%) children were asymptomatic and symptomatic, respectively. Cranial ultrasound findings suggestive of congenital infection were observed in 7 of the 8 symptomatic children (87.5%; IC95%: 46.67-99.34%). Among the 58 asymptomatic infants, 53 underwent complete evaluation and 29/52 had abnormal cranial ultrasound results (55,7%; IC95%: 41.41 - 69,27%). The most prevalent findings was lenticulostriate vasculopathy with subependymal pseudocysts present in 13 of the /29 (43.3%) infants with cranial ultrasound. Other abnormal findings were isolated subependymal pseudocysts (11/29: 37.9%); single or periventricular calcifications and/or gliosis (4/29: 13.8%); and ventriculomegaly (4/29: 13,8%). Logistic regression analysis showed that only the presence of clinical findings predicted the occurrence of hearing loss. Cranial ultrasound findings were observed in 3 of asymptomatic infants (75.0%) while 26 (54.2%) of 48 infants with no hearing loss had abnormal imaging features (p=0,42; RR:2,38: IC95%: 0,26-21,39). None of the other factors risk were independely associated with development of hearing loss. The presence of thrombocytopenia and/or high level of gamma-glutamyltranspeptidase (?GT) was associated with cranial ultrasound findings on univariated analysis. No discrimination power was achieved using the area under the ROC curve to verify the association between CMV DNA load in the urine of the infected children and the developing of hearing loss, presence of cranial ultrasound findings and clinical signs at birth. Conclusions: Although a neonatal screening of cCMV will identify the majority of infected infants who are clinically asymptomatic, a significant proportion of them could benefit from a central nervous system image evaluation, since abnormal findings are frequent. Althoug it was not possible to determine risk factors that are independently associated to development of sensorineural hearing loss, cranial ultrasound findings could be a potential prognostic markers of adverse outcomes of congenital CMV in asymptomatic infants.

<p>According to the World Health Organization, disabling hearing loss affects nearly 466 million people worldwide. Sensorineural hearing loss (SNHL), which is characterized as damage to the inner ear (e.g., cochlear hair cells) and/or to the neural pathways connecting the inner ear and brain, accounts for 90\% of all disabling hearing loss. One important clinical measure of SNHL is an auditory evoked potential called the auditory brainstem response (ABR). The ABR is a non-invasive measure of synchronous neural activity across the peripheral auditory pathway (auditory nerve to the midbrain), comprised of a series of multiple waves occurring within the first 10 milliseconds after stimulus onset. In humans, oftentimes ABRs are recorded using a high-density EEG electrode cap (e.g., with 32 channels). In our lab, a long-term goal is to establish and characterize reliable and efficient non-invasive measures of hearing loss in our pre-clinical chinchilla models of SNHL that can be directly related to human clinical measures. Thus, bridging the gap between chinchilla and human data collection by using analogous measures is imperative. \par</p><p><br></p><p>For this project, a 32-channel EEG electrode mini-cap for recording ABRs in chinchillas was studied. Firstly, the feasibility of this new method to record ABRs demonstrated. Secondly, the sources of bias and variability relevant to the mini cap were investigated. In this investigation, the ability of the mini cap to produce highly reliable, repeatable, reproducible, and valid ABRs was verified. Finally, the benefits of this new method, in comparison to our current approach using three subdermal electrodes, were characterized. It was found that ABR responses were comparable across channels both in magnitude and morphology when referenced to a tiptrode in the ipsilateral ear canal. Consequently, averaging across several channels led to a reduction in overall noise and the need for fewer repetitions (in comparison to the subdermal method) to obtain reliable response. Other methodological benefits of the mini cap included closer alignment with human ABR data collection, more efficient data collection, and capability for more in-depth data analyses, like source localization (e.g., in cortical responses). Future work will include collecting ABRs using the EEG mini-cap before and after noise exposure, as well as exploring the potential to leverage different channels to isolate brainstem and midbrain contributions to evoked responses from simultaneous recordings. </p>

<p>Disabling hearing loss is a problem around the world, with the World Health Organization estimating that 466 million people worldwide have disabling loss, and that this number is expected to increase to over 900 million people by 2050. There are different types of hearing loss, but sensorineural hearing loss (SNHL) is the most common and results from damage to the inner ear. The audiogram is the most common test used to diagnose hearing loss, but it is limited in that it can only identify a shift in hearing sensitivity (thresholds), i.e., it cannot identify the cochlear location causing SNHL. The electrocochleogram (ECochG) is an evoked response consisting of several summed responses of electrical potentials from within the inner ear. Several components represent activity from different places in the inner ear: the compound action potential (CAP) is the summed onset response of auditory nerve fibers, the cochlear microphonic (CM) is the AC response of the hair cells (primarily outer hair cells), and the summating potential (SP) is the DC hair cell response (primarily inner hair cells). Most ECochG responses in humans are collected non-invasively (e.g., from the ear canal or ear drum), whereas most ECochG responses in animal models are collected invasively (e.g., from the cochlear round window). <br></p><p></p><p>In this project, we aimed to bridge this gap by recording non-invasive ECochG responses from awake chinchillas. We first started by calculating standard ECochG metrics from existing data across different forms of SNHL. Next, we tested the feasibility of recording non-invasive ECochG responses from the ear canals of awake chinchillas. Finally, we defined and calculated additional metrics from ECochG responses to further help in identifying location(s) of SNHL. The ability demonstrated here to record non-invasive ECochG responses from awake animals increases the translational applicability of pre-clinical SNHL animal models by permitting detailed cochlear assessments at multiple time points post exposure. Detailed ECochG measures can advance hearing science and audiology by helping to identify the location of damage causing the hearing loss, which can ultimately allow for more individualized treatment. </p><br>

The ability to resolve rapid intensity and frequency fluctuations in sound is important for understanding speech, especially in real-world environments that include background noise and reverberation. Older listeners often complain of difficulties understanding speech in such real-world environments. One factor thought to influence speech understanding in noisy and reverberant environments is temporal resolution, the ability to follow rapid acoustic changes over time. Temporal resolution is thought to help listeners resolve rapid acoustic changes in speech as well as use small glimpses of speech available in the dips or gaps in the background sounds. Temporal resolution is an ability that is known to deteriorate with age and hearing loss, negatively affecting the ability to understand speech in noisy real-world environments. Measures of temporal resolution, including temporal masking, gap detection, and speech in interrupted noise, use a silent gap as the cue of interest. Temporal masking and speech in interrupted noise tasks measure how well a listener resolves a stimulus before, after, or between sounds (i.e., within a silent gap), while gap detection tasks measure how well the listener resolves the timing of a silent gap itself. A listener needs to resolve information within the gap and the timing of the gap when listening to speech in background sounds. This study examined the role of aging and hearing loss on three measures of temporal resolution: temporal masking, gap detection, and speech understanding in interrupted noise. For all three measures, participants were young listeners with normal hearing (n = 8, mean age = 25.4 years) and older listeners with hearing loss (n = 9, mean age = 72.1 years). Results showed significant differences between listener groups for all three temporal measures. Specifically, older listeners with hearing loss had higher temporal masked thresholds, larger gap detection thresholds, and required a higher signal-to-noise ratio for speech understanding in interrupted noise. Relations between temporal tasks were observed. Temporal masked thresholds and gap detection thresholds accounted for a significant amount of the variance in speech-in-noise scores. Findings suggest that deficits in temporal resolution abilities may contribute to the speech-in-noise difficulties reported by older listeners.

Background: This is a case study of an 18-year-old female who suffered a bilateral idiopathic sensorineural hearing loss that was coincident with the removal of four impacted wisdom teeth. Throughout childhood the patient had normal hearing for pure tones bilaterally as measured at the pediatrician's office. One month prior to dental surgery (May) the patient volunteered to participate in an auditory experiment at which time her pure-tone audiogram was normal. Immediately following surgery (June), the patient had substantial swelling of the face and complained of some hearing loss with no other auditory/vestibular complaints. The following month (July) during the course of a routine physical examination a pure-tone audiogram revealed bilateral, air-conduction thresholds of 30-35 dB HL (500-4000 Hz) and 20 dB HL (8000 Hz). Because bone conduction was not tested, it is impossible to know whether the hearing loss was conductive, mixed, or sensorineural. The pediatrician thought that the hearing loss was conductive and would resolve as the edema subsided. A month later (August) the subject again volunteered for an auditory experiment at which time her hearing again was tested. Purpose: The purpose of this report is to detail the dental procedures involved in the extraction of the wisdom teeth, to report the results of a variety and series of post-op hearing tests, and to discuss the possible mechanisms that might be involved in the ''idiopathic'' bilateral sensorineural hearing loss. Research Design: Case report. Results: During the August visit to the laboratory, hearing for pure tones bilaterally was 0 to 5 dB HL at 250-1000 Hz with a 40-45 dB HL notch at 2000 Hz with a return to 10 dB HL at 8000 Hz. Air conduction and bone conduction thresholds were equivalent. Word recognition in quiet was ≥92 percent correct for both ears, whereas the signal-to-noise ratio (SNR) hearing loss measured with the Words-in-Noise test was high normal in the left ear with a mild SNR hearing loss in the right ear. Tympanometry and acoustic reflex thresholds were normal. Distortion product otoacoustic emissions were reduced in the 1000-3000 Hz region for both ears, which is consistent with cochlear hearing loss. The hearing loss has remained unchanged for the past 19 months. Conclusions: The possible etiologies, including insults to the cochleae by vibration trauma and through alterations in the blood supply to the cochleae, are considered.

Background: Two previous experiments from our laboratory with 70 interrupted monosyllabic words demonstrated that recognition performance was influenced by the temporal location of the interruption pattern. The interruption pattern (10 interruptions/sec, 50% duty cycle) was always the same and referenced word onset; the only difference between the patterns was the temporal location of the onand off-segments of the interruption cycle. In the first study, both young and older listeners obtained better recognition performances when the initial on-segment coincided with word onset than when the initial on-segment was delayed by 50 msec. The second experiment with 24 young listeners detailed recognition performance as the interruption pattern was incremented in 10-msec steps through the 0-To 90-msec onset range. Across the onset conditions, 95% of the functions were either flat or U-shaped. Purpose: To define the effects that interruption pattern locations had on word recognition by older listeners with sensorineural hearing loss as the interruption pattern incremented, re: Word onset, from 0 to 90 msec in 10-msec steps. Research Design: A repeated-measures design with ten interruption patterns (onset conditions) and one uninterruption condition. Study Sample: Twenty-four older males (mean = 69.6 yr) with sensorineural hearing loss participated in two 1-hour sessions. The three-frequency pure-Tone average was 24.0 dB HL and word recognition was $80% correct. Data Collection and Analyses: Seventy consonant-vowel nucleus-consonant words formed the corpus of materials with 25 additional words used for practice. For each participant, the 700 interrupted stimuli (70 words by 10 onset conditions), the 70 words uninterrupted, and two practice lists each were randomized and recorded on compact disc in 33 tracks of 25 words each. Results: The data were analyzed at the participant and word levels and compared to the results obtained earlier on 24 young listeners with normal hearing. The mean recognition performance on the 70 words uninterrupted was 91.0% with an overallmean performance on the ten interruption conditions of 63.2% (range: 57.9-69.3%), compared to 80.4% (range: 73.0-87.7%) obtained earlier on the young adults. The best performances were at the extremes of the onset conditions. Standard deviations ranged from 22.1% to 28.1% (24 participants) and from 9.2% to 12.8% (70 words). An arithmetic algorithm categorized the shapes of the psychometric functions across the ten onset conditions.With the older participants in the current study, 40% of the functions were flat, 41.4% were U-shaped, and 18.6% were inverted U-shaped, which compared favorably to the function shapes by the young listeners in the earlier study of 50.0%, 41.4%, and 8.6%, respectively. There were two words on which the older listeners had 40% better performances. Conclusion: Collectively, the data are orderly, but at the individual word or participant level, the data are somewhat volatile, which may reflect auditory processing differences between the participant groups. The diversity of recognition performances by the older listeners on the ten interruption conditions with each of the 70 words supports the notion that the term hearing loss is inclusive of processes well beyond the filtering produced by end-organ sensitivity deficits.

The auditory brainstem response is an evoked potential that can be clinically used to estimate hearing sensitivity and to identify auditory nervous system pathology. Recently, there has been an increase in the implementation of the CE-Chirp stimulus in AABR equipment for neonatal hearing screening. The purpose of this study is to evaluate the diagnostic accuracy of the LS CE-Chirp-evoked ABR compared to the traditionally used click-evoked ABR for the identification of different degrees and configurations of sensorineural (SNHL) hearing loss. An exploratory within-subject comparative research design was used. 49 ears with mild to moderate sensorineural hearing loss were assessed. Participants were assessed in a single session. Audiometric pure tone thresholds were obtained at 125-8000 Hz and ABR thresholds were measured using the click and LS CE-Chirp stimuli respectively. Click- and LS CE-Chirp-evoked thresholds were compared with each other and with behavioural pure tone average (PTA), high frequency average (HFA) and low frequency average (LFA). Diagnostic accuracy of the two ABR stimuli was also compared by using ROC curves. Differences between click- and LS CE Chirp-evoked ABR, and behavioural thresholds were not statistically significant (p>0.05). The strongest significant correlation for ABR using clicks to behavioural thresholds was found at 2000 and 4000 Hz, whereas, the strongest correlation for LS CE-Chirp ABRs to behavioural thresholds was found at 1000, 2000 and 4000 Hz (r>0.7, p<0.001). A very strong, positive correlation was found between both click (r=0.805) and LS CE-Chirp (r=0.825) and the behavioural PTA (p<0.001). The mean differences for LS CE-Chirp were smaller than those of the click for PTA and low frequency range. ROC curves indicated better AUC values for the LS CE-Chirp at LFA and HFA compared to the click, also showing a narrower confidence interval and less variance than the click. The predictive accuracy of the LS CE-Chirp-evoked ABR was slightly better than that of the click with reference to PTA, HFA and LFA thresholds; furthermore, it is less variable and more accurate than the click-evoked ABR with reference to HFA. Thus, the LS CE-Chirp is an accurate stimulus for estimation of hearing sensitivity using ABR when compared to the gold standard click stimulus for the purpose of identification of different configurations of SNHL. / Dissertation (MA Audiology) University of Pretoria, 2019. / Speech-Language Pathology and Audiology / MA (Audiology) / Unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20798号 / 医博第4298号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 辻川 明孝, 教授 清水 章, 教授 戸口田 淳也 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM