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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

DEVELOPMENT AND MODIFICATION OF A GAUSSIAN AND NON-GAUSSIAN NOISE EXPOSURE SYSTEM

Schlag, Adam Wayne 01 December 2012 (has links)
Millions of people across the world currently have noise induced hearing loss, and many are working in conditions with both continuous Gaussian and non-Gaussian noises that could affect their hearing. It was hypothesized that the energy of the noise was the cause of the hearing loss and did not depend on temporal pattern of a noise. This was referred to as the equal energy hypothesis. This hypothesis has been shown to have limitations though. This means that there is a difference in the types of noise a person receives to induce hearing loss and it is necessary to build a system that can easily mimic various conditions to conduct research. This study builds a system that can produce both non-Gaussian impulse/impact noises and continuous Gaussian noise. It was found that the peak sound pressure level of the system could reach well above the needed 120 dB level to represent acoustic trauma and could replicate well above the 85 dB A-weighted sound pressure level to produce conditions of gradual developing hearing loss. The system reached a maximum of 150 dB sound peak pressure level and a maximum of 133 dB A-weighted sound pressure level. Various parameters could easily be adjusted to control the sound, such as the high and low cutoff frequency to center the sound at 4 kHz. The system build can easily be adjusted to create numerous sound conditions and will hopefully be modified and improved in hopes of eventually being used for animal studies to lead to the creation of a method to treat or prevent noise induced hearing loss.
62

Síndromes genéticas e ambientais em distúrbios da audição / Genetic and environmental syndromes in hearing loss disturbance

Nancy Mizue Kokitsu Nakata 18 October 2006 (has links)
Objetivos: estabelecer o diagnóstico de uma amostra de indivíduos com deficiência auditiva (DA) e comprometimento de outras estruturas anatômicas e/ou sistemas fisiológicos, cadastrados no CEDALVI/HRAC-USP-Bauru; verificar possíveis fatores etiológicos envolvidos e investigar possível correlação do tipo de DA com as diferentes síndromes encontradas. Local: Serviço de Genética Clínica do CEDALVI/HRAC-USP, Bauru-SP. Participantes: 93 indivíduos com DA e comprometimento de outras estruturas anatômicas e/ou sistemas fisiológicos. Intervenções: Avaliação genética-clínica; estudo citogenético; avaliações radiológica, oftalmológica, otorrinolaringológica, audiológica e outras. Resultados: Dos 93 indivíduos, 51 eram do sexo masculino e 42, do feminino. Recorrência familial foi observada em 31 casos e, consangüinidade parental em 8. Na amostra, 25 síndromes gênicas conhecidas, 5 síndromes cromossômicas, 5 quadros de etiologia ambiental e 2 quadros de etiologia heterogênea foram estabelecidos em 87 indivíduos. Em 1 caso, não foi possível definir entre 2 condições gênicas e em 5, não foi possível se chegar a um diagnóstico. Conclusões: a casuística se compôs de síndromes etiologicamente heterogêneas, com maior freqüência de etiologia genética; o tipo de DA nas síndromes gênicas foi condizente com o quadro diagnosticado; 3 indivíduos apresentaram síndromes ambientais clássicas, com diferentes tipos de DA; 2 indivíduos apresentaram quadro clínico, possivelmente decorrente de efeito teratogênico; implicação direta de fatores de risco para DA, na etiologia dessa, nos indivíduos com síndromes gênicas conhecidas sem DA; 1 caso, possivelmente, representa uma síndrome nova de padrão único, de etiologia desconhecida; o aconselhamento genético está na dependência da fase em que se encontra o processo de delineamento das diferentes condições estabelecidas. / Objectives: The purposes of this study were to establish the diagnostic of the individuals with hearing loss and presenting other additional anatomic structures and/or physiologic systems involvement, recorded in the CEDALVI/HRAC-USP-Bauru; to verify possible etiologic factors involved and to investigate a possible correlation of the hearing loss type with the different diagnosis syndromes. Setting: Clinical genetic service of the CEDALVI/HRAC-USP, Bauru- P. Participants: The sample was comprised of 93 individuals with hearing loss and involvement of other anatomic structures and/or physiologic systems. Interventions: Clinical genetic evaluation; cytogenetic study; radiological, ophtalmological, othorinolaryngological, audiologycal evaluation, etc. Results: From the total of the sample, 51 were male and 42 were female. Familial recurrence was observed in 31 cases and parental consanguinity in 8. In the present sample, 25 known genic syndromes, 5 chromosomal syndromes, 5 environmental conditions, and 2 heterogeneous conditions were established in 87 individuals. The diagnosis was not established in 5 individuals and in 1 case it was not possible to define between 2 genic conditions. Conclusions: The casuistic was composed of etiologically heterogeneous syndromes with greater frequency of genetic etiology; the type of hearing loss in the genic syndromes was concordant with the diagnosed condition; 3 individuals presented classic environmental syndromes with different types of hearing loss; 2 individuals presented clinical picture, possibly due to teratogenic effect; hearing impairment related to risk factors of the hearing loss in the individuals with known genic syndromes without hearing loss; probable a new unique-pattern syndrome, of unknown etiology in 1 case; the genetic counseling will depend on the step of delineation process of the different diagnosed condition.
63

Desempenho de crianças com perda auditiva leve no teste da habilidade de atenção auditiva sustentada - THAAS / Performance of children with a mild hearing loss in Sustained Auditory Attention Ability Test.

Maria Fernanda Capoani Garcia Mondelli 15 October 2007 (has links)
Objetivo: Verificar o desempenho de crianças diagnosticadas com deficiência auditiva, de grau leve, condutiva e sensorioneural, no Teste da Habilidade de Atenção Auditiva Sustentada (THAAS) visando constatar se este teste sofre influência da presença de uma deficiência auditiva. Modelo: Estudo do Teste da Habilidade de Atenção Auditiva Sustentada-THAAS em três grupos: grupo 1 (G1) grupo controle, formado por crianças com audição normal; grupo 2 (G2) crianças com deficiência auditiva sensorioneural bilateral de grau leve e grupo 3 (G3) composto por crianças com perda auditiva condutiva bilateral de grau leve. Local: Divisão de Saúde Auditiva ? Hospital de Reabilitação de Aanomalias Craniofaciais ?Universidade de São Paulo (HRAC/USP). Participantes: 90 crianças com idade entre 7 e 11 anos de idade, sendo 30 de cada grupo. Intervenções: Audiometria Tonal Limiar, Imitanciometria e THAAS Resultados: não houve indícios estatisticamente significativos entre sexo e idade, em todos os grupos estudados. Os grupos sensorioneural e condutivo apresentaram desempenho inferior ao grupo controle, em todas as respostas do THAAS. Conclusões: o teste THAAS sofreu influência das perdas auditivas de grau leve, condutivas e sensorioneurais na população estudada, sendo o pior comprometimento para perdas sensorioneurais. / Objective: To verify the performance of children diagnosed with a hearing loss of mild degree, conductive and sensorineural, at Sustained Auditory Attention Ability Test (SAAAT), aiming to observe if this test suffers the influence of the presence of a hearing loss. Model: A study of the Sustained Auditory Attention Ability Test ? SAAAT in three groups: group 1 (G1) control group comprising children with normal hearing, group 2 (G2) children with a bilateral sensorineural hearing loss of a mild degree and group 3 (G3), comprising children with a bilateral conductive hearing loss of a mild degree. Place: Division for Hearing Health ? Craniofacial Anomaly Rehabilitation Hospita, University of São Paulo (HRAC/USP). Participants: 7 to 11 year old children, 30 for each group. Interventions: Pure Tone Audiometry, Immitance Acoustic and SAAAT. Results: There were not any statistically significant indications between sex and age in all studied groups. Sensorineural and conductive groups showed a lower performance related to control group in all answers for SAAAT. Conclusions: SAAAT test suffered the influence of conductive and sensorineural hearing losses of light degree in studied population, the worse compromise occurring for sensorineural losses.
64

Incidence of hearing loss in young and elderly patients following spinal anaesthesia for cystoscopy

Mpholo, Lebogang Thateng January 2011 (has links)
Thesis (M.Med. ( Anaesthesiology)) --University of Limpopo (Medunsa Campus), 2011 / Introduction: Multiple studies have described a variable incidence of transient hearing loss (hypoacousis) from 0.4% to 40% after subarachnoid block, especially in the low-frequencies range (125 – 500 Hz) (1, 2). The mechanism of transient hypoacousis is attributed to leakage of cerebrospinal fluid, which leads to a decrease in perilymph pressure within the cochlear. Hypothesis: The study hypothesis was based on an assumption that hearing loss is more frequent in young patients who undergo spinal anaesthesia in comparison with elderly patients. Objective: 1) To determine the incidence of hearing loss after spinal anaesthesia in the young versus elderly patients. Materials and Methods: Ninety-eight male patients (ASA 1 - 11) scheduled for cystoscopy under spinal anaesthesia were recruited for the study. Recruitment of patients for the study was age dependent and was divided into two groups: One group (49 patients) had patients aged between 17 and 44 years (Group Y) and the other group had 49 patients aged between 45 and 77 years made up group two (GROUP E). Subarachnoid injection at L3-4 was performed using a standard 22-gauge Quincke spinal needle with patients in the sitting position and 2,5 ml to 3 ml of 0.5% isobaric bupivacaine was administered. Patients were evaluated on the day before spinal anaesthesia by pure tone audiometry at three different frequency sounds viz. 125 – 500 Hz (Low frequency), 500 – 2000 Hz (Speech frequency) and at 2000 – 4000 Hz (High frequency). This assessment was repeated 48 hours after the spinal block was given Statistical Analysis: Analysis was descriptive providing information on the mean (or median) and standard deviation of the variables for each of the two groups. The results of the audiometry were analyzed using repeated measures analysis of variance and transformation to p-value. Differences in outcomes of the study between the two groups were recorded as being statistically significant if p-value is ≤ 0.05. Results: No patient from the two groups developed hearing loss either at low or high frequencies. However, there was a statistically significant improvement in audiometric results (p-value ranging from 0.0001 and 0.063) 48 hours post-surgery in the elderly group as compared with patients in the younger group. Conclusion: The study revealed no hearing loss post-spinal anaesthesia in both groups. It did, however, show that the elderly group have better hearing acuity at all three frequency levels of sound compared to the younger group after spinal anaesthesia
65

Bilateral Idiopathic Sensorineural Hearing Loss Following Dental Surgery

Wilson, Richard H., Witkowski, Charles E., Wilson, Ashley A. 27 November 2009 (has links)
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.
66

Process Review of <I>GJB6</i> Reflex Testing in Individuals with 0 or 1 <i>GJB2</i> Pathogenic Variants and Non-Syndromic Hearing Loss

Supinger, Rachel Christine 10 August 2017 (has links)
No description available.
67

Estudo da heterogeneidade genética da surdez por sequenciamento de nova geração / Study of genetic heterogeneity of deafness by next-generation sequencing

Dias, Alex Marcel Moreira 04 December 2018 (has links)
Surdez e perda auditiva são termos utilizados para designar distúrbios da audição, o tipo de deficiência sensorial mais frequente em humanos e decorrente de alterações genéticas em cerca de 50% dos casos. A heterogeneidade de lócus, de alelos e de manifestações fenotípicas na surdez é impressionante. O lócus DFNB1, que contém os genes GJB2 e GJB6, é responsável por cerca de 40% dos casos de surdez não-sindrômica de origem genética, porém, variantes patogênicas em cerca de 150 genes são descritas como causa de surdez, que pode ser sindrômica ou não-sindrômica. Por permitirem o sequenciamento simultâneo de diversos genes em uma mesma análise, as técnicas de sequenciamento de nova geração têm sido empregadas para o diagnóstico molecular de condições geneticamente heterogêneas, incluindo a surdez. O objetivo desse estudo foi contribuir para o estudo da heterogeneidade genética da surdez por meio do sequenciamento de nova geração de um painel com 99 genes relacionados à perda auditiva. Indivíduos não aparentados de 91 famílias brasileiras, com provável causa genética de surdez, foram avaliados com o intuito de identificar as causas moleculares da surdez, detectar novas variantes e promover aconselhamento genético das famílias participantes do estudo. Variantes provavelmente causais foram detectadas em 41 dos 91 probandos analisados (45,1%), dos quais 34 (37,4%) apresentaram variantes patogênicas ou provavelmente patogênicas. Nos outros 7 casos, foram detectadas variantes de efeito desconhecido com elevado potencial de explicar a perda auditiva dos probandos. As taxas de detecção nos casos de provável surdez sindrômica foram de 44,4% no grupo com suspeita de síndrome de Waardenburg (4 de 9 casos) e de 61,5% no grupo com suspeita de síndrome de Usher (8 de 13 casos). Nos casos de surdez não-sindrômica, as taxas de detecção foram de 53,9% no grupo com provável surdez autossômica dominante, 35,1% no grupo com provável surdez autossômica recessiva e de 45,0 % no grupo com mais de um mecanismo de herança possível. Das 43 variantes classificadas como patogênicas ou provavelmente patogênicas detectadas nesse estudo, 15 nunca haviam sido descritas. Contribuições científicas importantes foram obtidas com a identificação de uma nova variante de perda de função no gene CEACAM16 como causa de surdez não-sindrômica autossômica recessiva e com a confirmação de uma variante no gene MYO3A como causa de surdez não-sindrômica autossômica dominante recém-descrita em famílias brasileiras. Os resultados obtidos permitiram concluir que o sequenciamento de nova geração de paineis multigênicos é uma estratégia eficaz para o estudo da heterogeneidade genética da surdez, contribuindo para a detecção de novas variantes, ampliando o conhecimento científico a respeito dos genes analisados, e para o aconselhamento genético dos indivíduos estudados e seus familiares / Deafness and hearing loss are terms used to describe hearing disorders, the most common type of sensory impairment in humans, which occurs due to genetic alterations in about 50% of cases. The heterogeneity of locus, alleles and phenotypic manifestations of deafness is striking. The DFNB1 locus, which contains the genes GJB2 and GJB6, is responsible for about 40% of cases of non-syndromic genetic hearing loss, but pathogenic variants in near 150 genes are described as causing deafness, which may be syndromic or non-syndromic. By allowing the simultaneous sequencing of several genes in the same analysis, next-generation sequencing techniques have been employed for the molecular diagnosis of genetically heterogeneous conditions, including deafness. The aim of this study was to contribute to the study of the genetic heterogeneity of deafness employing the next-generation sequencing of a panel with 99 genes related to hearing loss. Individuals from 91 unrelated Brazilian families, with a probable genetic cause for deafness, were evaluated with the purpose of identifying the molecular causes of deafness, to detect new variants and to provide genetic counseling to the families enrolled in the study. Probably causal variants were detected in 41 of the 91 probands analyzed (45.1%), of which 34 (37.4%) had pathogenic or likely pathogenic variants. In the other 7 cases, variants of unknown significance with high potential to explain the hearing loss were detected. Detection rates in cases of probable syndromic deafness were 44.4% in the group with suspected Waardenburg syndrome (4 of 9 cases) and 61.5% in the group with suspected Usher syndrome (8 of 13 cases). In cases of non-syndromic deafness, detection rates were 53.9% in the group with probable autosomal dominant inheritance, 35.1% in the group with probable autosomal recessive inheritance and 45.0% in the group with more than one possible mechanism of inheritance. Among the 43 variants classified as pathogenic or probably pathogenic detected in this study, 15 had never been described. Important scientific contributions were obtained such as the identification of a novel loss-of-function variant in the CEACAM16 gene as causing autosomal recessive non-syndromic deafness and the confirmation of a recently described variant in the MYO3A gene as causing autosomal dominant non-syndromic deafness in Brazilian families. The results obtained allowed us to conclude that next-generation sequencing of multigenic panels is an effective strategy for the study of the genetic heterogeneity of deafness, contributing to the detection of new variants, expanding scientific knowledge about the genes analyzed, and also to the genetic counseling of the individuals studied and their relatives
68

Noise-induced hearing loss : prevalence, degree and impairment criteria in South African gold miners

Strauss, Susan 15 January 2013 (has links)
Despite the preventability of noise-induced hearing loss (NIHL) a high prevalence is still reported in South African mines. The study aimed to describe the hearing of gold miners pertaining to the prevalence and degree of NIHL and effectiveness of current RSA impairment criteria to identify NIHL. The audiological data, collected between 2001 and 2008, of 57 714 mine workers were investigated in this retrospective cohort study. Data was accessed through the mine’s electronic database and exported to Microsoft Excel 2007 worksheets. Participants were categorised in terms of noise exposure (level and working years), age, race and gender. Noise exposure levels were described in terms of a specific occupation and categorized into four groups based on dosimeter data received from the mine’s noise hygienist, namely: 1) Below surface (underground) noise exposure, ≥85 dB A, classified according to the South African regulations on the daily permissible dose of noise exposure8, named Noise Group 1; 2) Surface noise exposure, ≥85 dB A, named Noise Group 2; 3) No known occupational noise exposure, named control group; and 4) Uncertain levels of noise exposure, e.g. students and trainees, named Noise Group 4. The control group was matched with participants of noise group 1 and 2 based on gender, race and age at the most recent audiogram test. Descriptive and inferential statistics were employed. Measures of central tendency and variability were used with analysis of covariance (ANCOVA) and pairwise comparisons according to Fisher’s Least Squares Differences Approach (F test). Results indicated that noise exposed groups had significantly higher prevalence of high and low frequency hearing loss than the control group. High-frequency hearing loss was also present in the control group. The greatest differences in prevalence of hearing loss were observed at 3, 4 kHz and age group 36 to 45 years. Thresholds at 8 kHz were worse than expected and decline slowed down with age. High-frequency thresholds showed a non-linear growth pattern with age with a greater decline at 2 kHz with age in the noise-exposed population compared to the control group. Hearing deteriorated more across age groups with more noise-exposed years, and this deterioration was most visible after 10 to 15 working years and at 3 kHz. Females had better hearing than males across the frequency spectrum. Black males had significantly better high-frequency hearing than white males but significantly worse low-frequency hearing than white male counterparts. PLH values showed poor correlation (through statistical analyses) with other well-accepted hearing impairment criteria. To date this was the largest study conducted on the hearing of gold miners and the sample included a very large number of black males exposed to occupational noise (N=17 933). Values supplied in distribution table format are therefore unique and contribute greatly to the knowledge base. / Thesis (PhD)--University of Pretoria, 2012. / Speech-Language Pathology and Audiology / unrestricted
69

Communicating with a Patient with Hearing Loss: Development of a Health Care Provider's Guide and Interprofessional Training

Dunne, Melanie C. January 2016 (has links)
Communication between a patient with hearing loss and a health care provider can be challenging and potentially contribute to poor health outcomes. This document describes an audiology doctoral project with clinical innovation emphasis on the development of a guide and interprofessional training for health care providers to communicate effectively with patients with hearing loss. A preliminary assessment of provider needs for training was followed by the development and implementation of an interprofessional training on hearing loss and communication strategies for the University of Arizona-St. Luke's Home Interprofessional Education and Practice Program (Spring, 2015). Additionally, video training segments on effective communication in a health care setting were developed. Evaluation of the interprofessional training included administration of pre- and post-training questionnaires (n = 11). Results indicated a significant change in trainee confidence levels in screening for hearing loss and the use of appropriate communication strategies for communicating with hard of hearing patients. These results support further development and research on hearing loss and communication training for health care curriculums, interprofessional education, and in-service training meetings. Implementation of communication trainings may lead to improved patient-provider communication, with positive impact on health care experiences and outcomes for patients with hearing loss.
70

Functioning and disability in adults with hearing loss : the preparatory studies in the ICF Core sets for hearing loss project

Granberg, Sarah January 2015 (has links)
Hearing loss (HL) is a health condition that affects more than 360 million people worldwide. The findings from previous research point at the adverse relationship between adults with hearing loss and important aspects of everyday life such as social relations, communication and work-related tasks. However, the overall picture concerning the functional and disabling aspects of adults with HL re- mains incomplete. To identify the functional and disabling aspects, a conceptual and/or theoretical framework is required. The International Classification of Functioning, Disability and Health (ICF) offer a multidimensional framework based on bio-psycho-social assumptions about health. In previous research inves- tigations in which the ICF has been used, some utility problems in the linking (relating) of data to the classification have been highlighted. The aims of the present thesis were to explore the areas of functioning and disability of relevance for adults with HL and to explore how audiological data can be linked to ICF. The aims were explored by applying the methodology of the ‘interdisciplinary evidence-based approach to functioning and disability in adults with HL’, acknowledging the merging of three perspectives designated the Researcher, the Patient and the Professional perspective. Four studies that focus on the three perspectives were conducted. All results were linked to the ICF classification. The results were merged into a model designated ‘the integrative model of functioning and disability in adults with HL’. When the three perspectives were linked, the results revealed several aspects of relevance for the target group. Bodily (individual) dimensions, such as hear- ing, auditory perception, memory, attention, energy, and emotions, were acknowledged. Aspects of everyday life such as conversations, the usage of communication strategies, family relationships and work, were highlighted. Influential environmental factors, such as noise, assistive technical devices, the design of public buildings, social support and the attitudes of people in the envi- ronment, were also identified. In conclusion, interactions seemed to be vital as almost all identified aspects highlighted or were tied to this dimension of human functioning. Further, concerning the linking of the data it was acknowledged that the ICF and the research area of adult HL do not fully comply. Suggestions for improvements in future revisions of the ICF were highlighted and discussed. / <p>Funding agency: Oticon Foundation; Hörselforskningsfonden (Swedish HearingResearch Foundation); the Foundation for Audiological Research (FAR) Forskningskommitten, Region Örebro County</p>

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