Made available in DSpace on 2015-05-14T12:47:12Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2059659 bytes, checksum: f3d773c696e3797e353a21eae5946320 (MD5) Previous issue date: 2012-03-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / INTRODUCTION: NIHL (Noise Induced Hearing Loss) is a condition that results from the accumulation of prolonged exposure to noise, causing a slow and progressive hearing impairment, sensorneural, not very deep, but irreversible. The dentist, individuals exposed to noise in their workplace, is susceptible to NIHL. OBJECTIVE: To analyze the auditory and possible risk factors that interfere with the hearing of the dentists from USFs (Unidades de Saúde da Família / Familiar Health Unities) in Joao Pessoa / PB. METHODOLOGY: There were interviews, audiological evaluations, instrumental and environmental noises within 65 dentists from Family Health Units in Joao Pessoa / PB to identify auditory characteristics and risk factors for hearing-surgeons dentists by using proportion measures calculation for categorical variables, and having the Statistical Logistic Regression Method. RESULTS: It was observed that 43.07% of the dentists who were evaluated had lower hearing in, at least, some of the characteristic frequencies of NIHL. It was found that the main ear symptoms cited by these professionals were to have the sensation of hearing loss (55%), and buzzer (50%), and also that the instruments which showed values above the allowed limits were turbine high rotation (61%) and the compressor (55%). The variables considered as risk factors for hearing loss based on logistic regression were: age over 45 years old, working time more than 10 years, a feeling of hearing loss, tinnitus and noise level of the compressor greater than 85 dB. CONCLUSION: The ear symptoms (tinnitus and hearing loss) are presented in a large number of dentists, and the noise emitted by the instruments used by these professionals is often high, presenting some risk factors for Noise Induced Hearing Loss and some of them may be prevented or controlled through specific strategies. / INTRODUÇÃO: A Perda Auditiva Induzida por Ruído (PAIR) é uma patologia decorrente do acúmulo de exposições a ruído prolongadas, gerando uma deterioração auditiva progressiva e lenta, sensorioneural, geralmente não muito profunda mas irreversível. Sabe-se que o cirurgião-dentista, indivíduo exposto ao ruído no ambiente de trabalho, é susceptível à PAIR. OBJETIVO: Analisar o perfil auditivo e possíveis fatores de risco que interferem na audição dos cirurgiões-dentistas das USFs (Unidades de Saúde da Família) de João Pessoa/PB. METODOLOGIA: Realizaram-se entrevistas, avaliações audiológicas e dos ruídos instrumental e ambiental com 65 cirurgiões-dentistas das Unidades de Saúde da Família de João Pessoa /PB, a fim de identificar características do perfil auditivo e de fatores de risco para a audição dos cirurgiões-dentistas, utilizando o cálculo de medidas de proporção para as variáveis categóricas, e tendo como método estatístico a Regressão Logística. RESULTADOS: Observou-se que 43,07% dos cirurgiões-dentistas avaliados apresentaram rebaixamento auditivo em pelo menos alguma das frequências características da PAIR. Verificou-se ainda que os principais sintomas otológicos citados por estes profissionais foram a sensação de déficit auditivo (55%), e o zumbido (50%). Os instrumentos que mais se apresentaram com valores de intensidade acima dos limites permitidos foram a turbina de alta rotação (61%) e o compressor (55%). As variáveis consideradas como fatores de risco para a perda auditiva com base na Regressão Logística foram: idade acima de 45 anos, tempo de trabalho maior que 10 anos e nível de ruído do compressor maior que 85 dB, além da presença dos sintomas de sensação de déficit auditivo e zumbido. CONCLUSÃO: A sintomatologia otológica (zumbido e diminuição auditiva) está presente em grande número dos cirurgiões-dentistas e o ruído emitido pelos instrumentos utilizados por estes profissionais é muitas vezes elevado. Constataram-se alguns fatores de risco para a Perda Auditiva Induzida por Ruído, podendo alguns destes ser prevenidos ou controlados por meio de estratégias específicas.

Millions of people across the world are suffering from noise induced hearing loss (NIHL), especially under working conditions of either continuous Gaussian or non-Gaussian noise that might affect human's hearing function. Impulse noise is a typical non-Gaussian noise exposure in military and industry, and generates severe hearing loss problem. This study mainly focuses on characterization of impulse noise using digital signal analysis method and prediction of the auditory hazard of impulse noise induced hearing loss by the Auditory Hazard Assessment Algorithm for Humans (AHAAH) modeling. A digital noise exposure system has been developed to produce impulse noises with peak sound pressure level (SPL) up to 160 dB. The characterization of impulse noise generated by the system has been investigated and analyzed in both time and frequency domains. Furthermore, the effects of key parameters of impulse noise on auditory risk unit (ARU) are investigated using both simulated and experimental measured impulse noise signals in the AHAAH model. The results showed that the ARUs increased monotonically with the peak pressure (both P+ and P-) increasing. With increasing of the time duration, the ARUs increased first and then decreased, and the peak of ARUs appeared at about t = 0.2 ms (for both t+ and t-). In addition, the auditory hazard of experimental measured impulse noises signals demonstrated a monotonically increasing relationship between ARUs and system voltages.

Occupational hearing loss resulting from noise exposures encountered in the workplace affects millions of workers and costs hundreds of millions of dollars annually in Workers’ Compensation costs in the United States alone. Some industries have been well studied, and the presence of hazardous noise in the work environment established and documented. The restaurant industry is one in which little current data exists, but in which there may be cause for concern. This work sought to quantify noise exposures for cooks, servers, and dishwashers and to determine whether or not any of these workers are at risk for Noise Induced Hearing Loss. Further, the researchers wanted to know what environmental factors present in the restaurants had the greatest impact on noise exposures for each exposure group. Statistical analysis was conducted on selected factors, and while nearly all were found to have significant effects on noise exposure for servers, only the number of minutes worked explained variance in exposures for cooks and dishwashers when all factors were included in analysis. These two groups are the ones most likely to be overexposed and they typically worked more than 480 minutes on the day the sample was collected. Efforts to control exposure must take these extended shifts into careful account. The study was limited by relatively small sample size, with 124 cooks, 119 servers, and 91 dishwashers employed at nine different restaurants participating. Future efforts to explain and characterize the sources of variation in noise exposure for these three groups should include greater numbers of participants and structure the data in a way that allows the effects of selected factors to be more clearly seen.

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

<p>  </p> <p>Noise-induced hearing loss (NIHL) is a significant occupational health concern in the construction industry, necessitating effective hearing protection for workers. This project explores the detrimental consequences of environmental pollutants, specifically noise pollution common in construction settings. The research incorporates user interviews with construction workers and managers to identify challenges and motivations surrounding the use of hearing protection devices.</p> <p>My findings underscore the necessity of addressing pollution in the construction industry to safeguard the well-being of workers. Noise pollution emerges as a primary concern, leading to hearing loss, stress, decreased productivity, and safety hazards. The research revealed that workers grapple with obstacles, including discomfort, lack of awareness, and cost barriers, while also recognizing driving forces, including fear of hearing loss and the encouragement of supervisors. The design process involved thorough research, including a literature review, competitive analysis, and semi-structured user interviews, resulting in an advanced hearing protection device that prioritizes effective communication, cleanliness, and user comfort. The final product incorporates innovative features such as lighting indicators, a compact charging case, strategically positioned buttons, secure fit with magnets, and a range of color options. Furthermore, the accompanying application features customizable ambient sounds, performance feedback, and gamification elements.</p>

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In der vorliegenden Arbeit sind physiologische und anatomische Auswirkungen einer Lärmexposition auf subcortikale Strukturen des zentralen auditorischen Systems zu unterschiedlichen Zeitpunkten posttraumatisch untersucht worden. Dabei sollte zwischen akuten (TTS-Gruppe) und langfristigen Effekten (PTS-Gruppe) unterschieden werden. Normalhörende Mäuse wurden für 3 Stunden mit einem Bandrauschen (5-20 kHz) bei 115 dB SPL beschallt und mittels Hirnstammaudiometrie der Hörverlust bestimmt. In der TTS- und der PTS-Gruppe lag im Vergleich zur Kontrolle eine signifikante Hörschwellenverschiebung mit einem höheren Hörverlust in der TTS-Gruppe vor. Zur Untersuchung zentraler Veränderungen wurden neuronale Spontanaktivitäten mittels Einzelzellableitungen im Hirnschnitt ermittelt. Weiterhin sind histologisch die Zelldichten in den Versuchsgruppen bestimmt worden. Außerdem wurde ein manganverstärktes MRT durchgeführt, um die calciumabhängige Aktivität darzustellen. Die untersuchten auditorischen Strukturen waren der Nucleus cochlearis (CN), der inferiore Colliculus (IC) und der mediale Kniehöckers (MGB). Die Ergebnisse zeigen, dass es einen Unterschied in den akuten und langfristigen Auswirkungen einer Lärmexposition gibt. In der TTS-Gruppe sind ausschließlich die Kerngebiete des CN im Hirnstamm betroffen, was auf direkte Einwirkungen der Lärmexposition hindeutet und akute toxische Exzitation im Gewebe auslösen kann. In der PTS-Gruppe treten physiologische und anatomische Veränderung in höheren Strukturen der Hörbahn auf. Dabei kann es sich sowohl um späte direkte Lärmauswirkungen als auch um plastische Veränderungen handeln, die durch die lärminduzierte Deprivation ausgelöst wurden. Einerseits kommt es zu einem dramatischen Zellverlust in den untersuchten Gebieten. Zum anderen steigt die calciumabhängige Aktivität in einigen Strukturen stark an. Dies kann sowohl durch veränderte neuronale Aktivitätsmuster, aber auch durch plastische und neurodegenerative Prozesse bedingt sein. / In the present study, noise-induced physiological and anatomical changes in subcortical structures of the central auditory system were investigated at different posttraumatic stages. Thus, it should be distinguished between acute (TTS group) and long-term (PTS group) effects of noise damage. Normal hearing mice were exposed to a band noise (5-20 kHz) for 3 hours at 115 dB SPL. Auditory brainstem responses were measured to determine the produced hearing loss. A significant threshold shift was detectable in the TTS as well as in the PTS group. This effect was greater in TTS animals. To investigate central changes, neuronal spontaneous activities were recorded from single units in brain slices. Further, cell densities were determined by histological techniques. In addition, calcium dependent activity was measured using manganese enhanced MRI. Investigations were carried out in central auditory structures of the cochlear nucleus (CN), the inferior colliculus (IC) and the medial geniculate body (MGB). The results demonstrate a difference in acute and long-term effects of noise exposure. In the TTS group, only the CN in the brainstem was affected, indicating a direct noise impact leading to acute excitotoxicity. In the PTS group, physiological and anatomical changes could also be observed in higher structures of the auditory pathway. The effects can be related to long-lasting noise damage as well as neural plasticity caused by deprivation of auditory input. The results show a dramatic cell loss within the investigated structures. Further, there is an increase in calcium dependent activity in several auditory brain regions which can be caused by changes in neuronal activity patterns, neuroplasticity and neurodegenerative processes.