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.

Excerpt: It is often the case that veterans who experience hyperacusis have hearing loss and tinnitus; what sets the patient with PTSD apart is an increased likelihood that will rate sound tolerance problems as more severe than tinnitus and hearing loss.

Thesis--University of Oklahoma. / Includes bibliographical references (leaves 52-53).

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.

Auditory filters were derived in 20 normal-hearing human listeners at center frequencies (CFs) of 913, 1095, 3651, and 4382 Hz using the roex (p,r) method. Comparisons were made between slopes of the filters' skirts at the neighboring CFs with filter output levels of 45 and 70 dB. The same comparisons were made with regard to filter equivalent rectangular bandwidth (ERB). In the 1000-Hz region, the low-frequency slopes (Pl) of filters centered at 913 and 1095 Hz were significantly correlated at both stimulus levels, while the high-frequency slopes (Pu) were similar only at the high test level. In the 4000-Hz region, for sinusoids of 3651 and 4382 Hz, the level effect was clearer as both Pu and Pl values diverged at the low level but were related at high levels. The ERBs centered at the same CFs displayed a similar level dependence. At the stimulus level most likely to be affected by an active feedback mechanism, auditory filters centered at nearly the same frequency displayed quite distinct frequency selectivity, and this trend was stronger in the 4000-Hz region than the 1000-Hz region. The findings suggest that a saturating, active cochlear mechanism may not be distributed evenly, or contribute to peripheral tuning with equal effectiveness throughout the length of the partition.

Effective cochlear implant fitting (or programming) is essential for providing good hearing outcomes, yet it is a subjective and error-prone task. The initial objective of this research was to automate the procedure using the auditory nerve electrically evoked compound action potential (the ECAP) and machine intelligence. The Nucleus?? cochlear implant measures the ECAP via its Neural Response Telemetry (NRT™) system. AutoNRT™, a commercial intelligent system that measures ECAP thresholds with the Nucleus Freedom™ implant, was firstly developed in this research. AutoNRT uses decision tree expert systems that automatically recognise ECAPs. The algorithm approaches threshold from lower stimulus levels, ensuring recipient safety during postoperative measurements. Clinical studies have demonstrated success on approximately 95% of electrodes, measured with the same efficacy as a human expert. NRT features other than ECAP threshold, such as the ECAP recovery function, could not be measured with similar success rates, precluding further automation and loudness prediction from data mining results. Despite this outcome, a better application of the ECAP threshold profile towards fitting was established. Since C-level profiles (the contour of maximum acceptable stimulus levels across the implant array) were observed to be flatter than T-level profiles (the contour of minimum audibility), a flattening of the ECAP threshold profile was adopted when applied as a fitting profile at higher stimulus levels. Clinical benefits of this profile scaling technique were demonstrated in a 42 subject study. Data mining results also provided an insight into the ECAP recovery function and refractoriness. It is argued that the ECAP recovery function is heavily influenced by the size of the recruited neural population, with evidence gathered from a computational model of the cat auditory nerve and NRT measurements with 21 human subjects. Slower ECAP recovery, at equal loudness, is a consequence of greater neural recruitment leading to lower mean spike probabilities. This view can explain the counterintuitive association between slower ECAP recovery and greater temporal responsiveness to increasing stimulation rate. This thesis presents the first attempt at achieving completely automated cochlear implant fitting via machine intelligence; a future generation implant, capable of high fidelity auditory system measurements, may realise the ultimate objective.

Effective management of the potential environmental impacts of naval sonar requires quantitative data on the behaviour and hearing physiology of cetaceans. Here, novel experimental and analytical methods were used to obtain such information and to test the effectiveness of an operational mitigation method for naval sonar. A Bayesian method was developed to estimate whale locations through time, integrating visual observations with measurements from on-animal inertial, acoustic, depth, and Fastloc-GPS sensors. The track reconstruction method was applied to 13 humpback whale (Megaptera novaeangliae) data sets collected during a multi-disciplinary behavioural response study in Norwegian waters. Thirty-one controlled exposure experiments with and without active transmissions of 1.3-2 kHz sounds were conducted using a moving vessel that towed a sonar source. Dose-response functions, representing the relationships between measured sonar dose and behavioural responses identified from the reconstructed tracks, predicted that 50% of the humpbacks would initiate avoidance at a relatively high received sound pressure level of 166 dB re 1 µPa. Very similar dose-response functions were obtained for cessation of feeding. In a laboratory study, behavioural reaction times of a harbour porpoise (Phocoena phocoena) to sonar-like sounds were measured using operant conditioning and a psychoacoustic method. Auditory weighting functions, which can be used to improve dose-response functions, were obtained for the porpoise based on the assumption that sounds of equal loudness elicit equal reaction time. Additional analyses of the humpback whale data set provided evidence that ramp-up of naval sonar mitigates harmful sound levels in responsive cetaceans located directly in the path of the source, and suggested that a subset of the humpback whale population, such as mother-calf pairs, and more responsive species would benefit from the use of sonar ramp-up. The findings in this thesis are intended to inform sound exposure criteria and mitigation guidelines for anthropogenic noise exposure to cetaceans.