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The relationship between Cantonese tonal confusions and audiometric configuration and sensitivity in the elderlyLeung, Kwok-shun, Eric. January 1900 (has links)
Thesis (B.Sc)--University of Hong Kong, 1992. / A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), University of Hong Kong, April 30, 1992. Also available in print.
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Histomorphologische und immunhistologische Charakterisierung altersassoziierter Veränderungen der Cochlea bei HundenScheil, Katrin 13 April 2010 (has links)
Eine der häufigsten Behinderungen des alternden Menschen stellt die Beeinträchtigung der Hörfunktion
durch degenerative Veränderungen der Cochlea, beispielsweise am Ganglion spirale,
am CORTI-Organs oder an der Stria vascularis dar. Basierend auf histologischen und funktionellen
Untersuchungen, wird die Altersschwerhörigkeit (Presbycusis) beim Menschen durch
SCHUKNECHT und GACEK (1993) in sechs verschiedenene Typen eingeteilt: sensorisch,
strial/metabolisch, neural, cochlear-konduktiv, gemischt, unbestimmt. Die in diesem Rahmen
auftretenden pathophysiologischen und pathomorphologischen Veränderungen der Cochlea sind
bedingt durch hörschädigende Faktoren (u.a. Lärm, ototoxische Substanzen, Infektionen sowie
genetische Ursachen), die im Laufe des Lebens im Bereich des peripheren Hörorgans und der
zentral auditiven Verarbeitung gewirkt haben.
Die meisten in der Literatur beschriebenen Untersuchungen, die sich mit cochleären Alterationen
mit zunehmendem Alter befassen, wurden an Labortieren unternommen und beschreiben oft nur
Alterationen einzelner Strukturen, nicht aber der gesamten Cochlea. Bei Hunden sind in der Literatur
überwiegend ausführliche Untersuchungen bezüglich der kongenitalen vererbten Taubheit,
z.B. bei Dalmatinern, beschrieben. Es existieren jedoch kaum Studien über altersbedingte morphologische
und funktionelle Veränderungen der Cochlea bei Hunden.
Das Ziel dieser Arbeit besteht daher in der (immun-) histologischen Untersuchung der Cochlea
von 50 Hunden im Alter von 7 Tagen bis 16 Jahren, um altersbedingte morphologische und
funktionelle Veränderungen in der Cochlea von Hunden, die nicht unter Laborbedingungen gehalten
wurden, zu charakterisieren und sie mit den Befunden an Innenohren von anderen Tierarten
und des Menschen zu vergleichen.
Anhand der erhobenen Befunde sollen anschließend eventuelle Rückschlüsse auf intra vitam
vorhandene Hörstörungen gezogen werden.
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Reconhecimento de monossílabos em idosos: análise do nível de apresentação da fala / Monosyllabic words recognition in elderly: analysis of the speech presentation levelSantana, Bruna Antonini 26 February 2016 (has links)
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.
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O sentido da audição e as dificuldades auditivas atribuídas por um grupo de idosos / The meaning of hearing and auditory difficulties for a group of elderly peopleSousa, Maria da Glória Canto de 09 October 2007 (has links)
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Previous issue date: 2007-10-09 / Hearing is one of the human senses that contribute the most for social interaction. The hearing loss in the elderly, known as presbycusis, involves the decrease in speech intelligibility, restraining communication and the social life of the elder. Communicative limitations may lead to isolation, harming their social relations, and interfering in their quality of life. Purpose: Characterize the perception that old adults have of their own hearing, plus the identification of aspects involved in their process of communication. Method: This study was done through the use of a descriptive and exploratory research, having 40 students, being 34 females and 6 males, with ages varying between 61 and 88 years old, from an university called: Universidade Aberta à Terceira Idade (UATI), located in the city of Salvador, in the state university, named Universidade do Estado da Bahia (UNEB). Foi aplicado um questionário denominado Inventário Auditivo para Idosos (IAPI) e realizado o exame audiométrico nos sujeitos. A análise dos dados foi feita a partir das variáveis: sexo, faixa etária e pela computação das respostas dadas pelos indivíduos ao Inventário Auditivo para Idosos - IAPI (Mesquita, 2001).The subjects answered to a questionnaire and undergo audiometric tests. The data analysis was done considering the variables: gender, age and the computed answers for the questionnaire (Mesquita, 2001). Results: 37.5% of the subjects presented normal hearing and 62.5% hearing loss, being 30% symmetrical and 32.5% asymmetrical. Out of 25 subjects with hearing loss, only 04 (16%) were aware of it with a score for the questionnaire over 10 and 21 (84%) under 10. Related to gender, 8% of men and women scored over 10; 16% of men and 68% of women had scores over 10. There was a descending audiometric configuration in 88% of the subjects. Conclusion: In relation to age and degree of hearing loss, the greater the age, the greater the hearing loss, being proportionally higher for males than for females. It is fundamental to be in harmony with this population in order to contribute with our portion of knowledge and help the ones who are in our tomorrow´s place / A audição é um dos sentidos humanos que mais contribui para a interação social. A perda auditiva na terceira idade, conhecida como presbiacusia, implica redução da inteligibilidade de fala, comprometendo a comunicação e a vida social do idoso. As limitações da comunicação podem levar o idoso a se isolar, prejudicando suas relações sociais, interferindo, assim, em sua qualidade de vida. Objetivo: caracterizar a percepção que os indivíduos idosos têm da sua audição, além da identificar os aspectos envolvidos no seu processo comunicativo. Método: Foi realizada uma pesquisa descritiva e exploratória, tendo como sujeitos 40 alunos, sendo 34 do sexo feminino e 06 do sexo masculino, com idades variando entre 61 anos e 88 anos, de uma Universidade Aberta à Terceira Idade (UATI), localizada na cidade do Salvador, na Universidade do Estado da Bahia (UNEB). Foi aplicado um questionário denominado Inventário Auditivo para Idosos (IAPI) e realizado o exame audiométrico nos sujeitos. A análise dos dados foi feita a partir das variáveis: sexo, faixa etária e pela computação das respostas dadas pelos indivíduos ao Inventário Auditivo para Idosos - IAPI (Mesquita, 2001). Resultados: 37,5% dos sujeitos apresentaram audição normal e 62,5% perda auditiva, sendo 30% perda auditiva assimétrica e 32,5% simétrica. Dos 25 sujeitos com perda auditiva apenas 04 (16%) tiveram percepção da mesma com um IAPI superior a dez pontos e 21 (84%) com uma pontuação inferior a dez. Quanto ao sexo, 8% de homens e mulheres tiveram uma pontuação superior a dez no IAPI; 16% dos indivíduos do sexo masculino e 68% do feminino apresentaram pontuação inferior a dez. Houve um predomínio da configuração audiométrica do tipo descendente em 88% dos sujeitos Conclusão: Com relação à faixa etária e ao grau da perda auditiva, quanto maior a idade maior a perda auditiva, sendo, proporcionalmente maior para o sexo masculino do que para o feminino. É necessário que estejamos em sintonia com essa população a fim de contribuir com nossa parcela de conhecimento e ajuda aos que estão hoje em nosso lugar amanhã
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Word Recognition in Noise among Young and Older Listeners: A Combined Behavioral and Electrophysiological StudyWilliams-Sanchez, Victoria Ann 17 November 2014 (has links)
Word recognition is based on the complex interplay of bottom up processing of acoustic input and corresponding top-down processing based on linguistic redundancies (i.e., contextual cues). Friedrich and Kotz (2007) investigated the timeline of integrating top-down and bottom-up processes among young adults with normal hearing using sentences presented in quiet. As a follow-up study, also with young adults with normal hearing (Experiment 1 of this dissertation), we used sentences embedded in multi-talker background noise and found similar results to Friedrich and Kotz (2007); but, with the use of principal component analysis (PCA) unveiled additional effects of phonological and semantic integration of spoken sentences presented in background noise. These past studies provide evidence of the time course of bottom-up and top-down mechanisms among young adult listeners in quiet and in noise; however, it is unknown if a similar pattern would be present among older adult listeners, which was the primary goal of the dissertation.
In Experiment 2, we aimed to elucidate the time-course, and behavioral and neural correlates of word recognition primed by speech-in-noise in older adults with near normal hearing (i.e., thresholds ≤ 25 dB-HL through 3000 Hz and minimal high frequency hearing loss). Older adults often report difficulty understanding speech in the presence of background noise. Degradation in peripheral and central auditory processing along with age-related cognitive decline has been hypothesized as reasons why older adults struggle in the presence of noise.
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The relationship between self-perceived benefit as measured by the APHAB, COSI and CPHI and the presence of ADP in an elderly population. [electronic resource] / by Michelle L. Bleiweiss.Bleiweiss, Michelle L. January 2002 (has links)
Professional research project (Au.D.)--University of South Florida, 2002. / Title from PDF of title page. / Document formatted into pages; contains 34 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The self-perceived hearing aid benefit of 38 participants was examined. Of the 38 subjects, 8 were found to have an auditory processing disorder as measured by the Dichotic Sentence Identification (DSI). When compared to the non-APD subjects, there were essentially no significant differences on the APHAB or COSI outcome measures. However, two of the 5 scales of the CHPI did show significant differences. In conclusion, these results do not support the notion of APD having a negative effect on hearing aid benefit. No finding in this study was robust and although there were several trends supporting that APD may impede an individual from receiving their full potential of benefit, this finding is not necessarily so. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
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Reconhecimento de monossílabos em idosos: análise do nível de apresentação da fala / Monosyllabic words recognition in elderly: analysis of the speech presentation levelBruna Antonini Santana 26 February 2016 (has links)
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.
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Neuropeptide Modulation of the Large Conductance Potassium (BK) Channel in the Auditory System: Therapeutic Implications for Age-Related Hearing LossBrecht, Ellliott James 04 April 2017 (has links)
The auditory temporal processing deficits associated with age-dependent hearing decline have been increasingly attributed to issues beyond peripheral hearing loss. Age-related hearing loss (ARHL), also known as presbycusis, is linked with changes in the expression of both excitatory and inhibitory neurotransmitters in the central auditory system. There are also age-related changes in the expression and function of the ion channels which mediate action potential firing. The slow, Ca2+ activated, K+ channels of the BK-type are essential in controlling both neurotransmitter release and neural communication via alteration of action potential durations, firing frequency, and neural adaptation. There are many subsets of this type of ion channel located throughout the body, and though it is evident that these channels are involved in cellular activation within the peripheral auditory system, little is known about their contribution to auditory processing in the brain. There is a need for further understanding of the functional involvement and mechanisms of neurotransmitter loss and how this relates to the BK channel and auditory disorders such as presbycusis and tinnitus (the perception of a phantom sound). My research focused on investigating how the downregulation of neurotransmitter production and the reductions in BK channel expression affect ARHL. I also evaluated a custom BK-channel modulating peptide as a path towards a possible therapeutic intervention for age-related hearing loss. This custom peptide is especially useful because it reduces the potential for serious side effects, due to mechanisms which best mimic natural occurring peptide systems.
The initial investigation described in this dissertation measured auditory system changes in aged mice that occurred following a drug-induced increase in the availability of the inhibitory neurotransmitter GABA. This increase in GABA decreased minimum response thresholds in the auditory midbrain of aged mice, bringing them to levels seen in young adult animals. The other changes that occurred following increased GABA availability were increased acoustically driven neuronal firing rates, frequency-dependent decreases in spontaneous rates, and increases in the symmetry of the receptive fields. The return of clear and fine-tuned acoustically-evoked responses in aged mice was a major finding of this experiment.
The second phase of the dissertation built on this demonstration that modulation of the aged auditory system was possible by changing neurotransmitter levels. This second portion of the study focused on how a novel potent neuropeptide (LS3), which increases the probability of the BK channel remaining in the closed conformational state, might invoke alterations in auditory-evoked responses. First, the LS3 neuropeptide was used to modify addictive behavior in the C. Elegans; followed by evaluation of in vitro changes to a human cell line. This study then confirmed that LS3 is a potent BK channel modulator with a greater affinity than those known toxins classified as high-affinity toxins. In vivo testing demonstrated that LS3 could rapidly cross the blood-brain barrier (BBB) following systemic injections, where it altered auditory evoked activity in a manner similar to that of the direct application to the dura over the midbrain. This work demonstrates that the BK channel is highly responsible for the control of auditory-evoked neurological processes, and that a potent BK channel modulator may be useful for the treatment of certain neurological disorders.
The third study was designed to confirm that the BK channel plays an important role in sound-evoked activity generated in the auditory midbrain, by testing the effects of a general BK channel pore blocker, PAX. The results established that the BK channel is vital for sound processing in the midbrain of young adult mice, and is responsible for the maintenance of receptive field properties. I also evaluated the role it plays in temporal processing, which is an underlying mechanism for the processing of neurologically-relevant complex acoustic signals such as speech. Here, blocking of the channel increased (worsened) the threshold for the detection of a silent gap-in-noise and the neural recovery functions that occurred following the stimuli.
The fourth study significantly expanded the in vivo testing of the custom peptide channel blocker, LS3, and added a behavioral measure of changes to auditory perception in addition to the electrophysiology recordings. The auditory-evoked receptive fields from midbrain neurons were modulated in a dose-dependent manner following the application of LS3. The neural recordings took place in the inferior colliculus, where the dorsal region responds to low-frequency sounds and ventral areas to high frequencies. The LS3-induced suppression or enhancement of evoked responses was different for the various tonotopic regions of the auditory midbrain. The improvements shown in receptive fields and improvement in auditory perception indicates a plausible route for direct translational treatment of auditory disorders through small custom peptide therapeutics. These studies provide supportive information about how auditory evoked responses in the midbrain, including the coding of different sound features, are affected by the down-regulation of a key inhibitory neurotransmitter (GABA), and how GABA-dependent neural evoked responses are altered in older mice through the modulation of BK channel activity.
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The Effects of Aging on Temporal MaskingFulton, Susan E 30 June 2010 (has links)
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.
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The 500 Hz Masking-Level Difference and Word Recognition in Multitalker Babble for 40- to 89-Year-Old Listeners With Symmetrical Sensorineural Hearing LossWilson, Richard H., Weakley, Deborah G. 01 December 2005 (has links)
The purpose of this study was to determine if performances on a 500 Hz MLD task and a word-recognition task in multitalker babble covaried or varied independently for listeners with normal hearing and for listeners with hearing loss. Young listeners with normal hearing (n = 25) and older listeners (25 per decade from 40-80 years, n = 125) with sensorineural hearing loss were studied. Thresholds at 500 and 1000 Hz were ≤30 dB HL and ≤40 dB HL, respectively, with thresholds above 1000 Hz <100 dB HL. There was no systematic relationship between the 500 Hz MLD and word-recognition performance in multitalker babble. Higher SoNo and SπNo thresholds were observed for the older listeners, but the MLDs were the same for all groups. Word recognition in babble in terms of signal-to-babble ratio was on average 6.5 (40- to 49-year-old group) to 10.8 dB (80- to 89-year-old group) poorer for the older listeners with hearing loss. Neither pure-tone thresholds nor word-recognition abilities in quiet accurately predicted word-recognition performance in multitalker babble.
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