Thesis (Doctoral)--Uppsala University, 1983. / Includes bibliographical references (p. 33-34).

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-15T14:14:47Z No. of bitstreams: 1 jacquelinedeassispinto.pdf: 1415006 bytes, checksum: 5007465a343c99ebcadca2bdb8d70d84 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-07-19T15:56:03Z (GMT) No. of bitstreams: 1 jacquelinedeassispinto.pdf: 1415006 bytes, checksum: 5007465a343c99ebcadca2bdb8d70d84 (MD5) / Made available in DSpace on 2016-07-19T15:56:03Z (GMT). No. of bitstreams: 1 jacquelinedeassispinto.pdf: 1415006 bytes, checksum: 5007465a343c99ebcadca2bdb8d70d84 (MD5) Previous issue date: 2011-03-28 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / OBJETIVOS: Estimar a presença de perda auditiva típica para ototoxicidade por uso disfuncional de alcoólicos — nomeadamente o uso freqüente de altas doses, por longo tempo — controladas por exposição a ruído ocupacional e idade; comparar os grupos de estudo a variáveis relativas a dados sociodemográficas; uso de alcoólicos, tabaco, outras substâncias psicoativas e saúde auditiva. MÉTODOS: Estudo de corte transversal, com homens em idade entre 30 até 50 anos, com histórico negativo de exposição a ruído ocupacional; exame otorrinolaringológico normal, incluídos em dois grupos: indivíduos com uso prévio disfuncional de alcoólicos e indivíduos que nunca fizeram uso disfuncional de alcoólicos. Submetidos a questionário para coleta de dados, exame otorrinolaringológico e avaliação audiológica básica. RESULTADOS: ocorreram diferenças significativas entre os dois grupos estudados para as variáveis: nível de escolaridade (p=0,007); remuneração (p=0,039) e presença de perdas auditivas típicas para ototoxicidade (p=0,002). 87,5% das perdas auditivas no grupo de alcoolistas foram perdas típicas para ototoxicidade, enquanto esta prevalência foi de apenas 25,0% dentre os indivíduos que nunca fizeram uso disfuncional de alcoólicos. As variáveis que apresentaram diferença significativa em relação a presença de perda auditiva típica para ototoxicidade foram: uso-na-vida de drogas (p=0,017), uso-na-vida de tabaco (p=0,000), relato de dificuldade para ouvir (p=0,00), presença de zumbido (p=0,004) e freqüência a cultos religiosos (p=0,034). No processo de regressão logística, o modelo final de regressão indicou que o uso prévio disfuncional de alcoólicos aumentou o risco em 990% e o uso-de-tabaco na vida aumentou o risco em 702%. CONCLUSÕES: os resultados reforçam a evidência de que o uso disfuncional de alcoólicos seja capaz de desencadear quadros de perda auditiva típica para Ototoxicidade. / OBJECTIVES: To estimate the presence of hearing loss for ototoxicity by typical dysfunctional use of alcohol - including the frequent use of high doses for a long time - controlled by occupational noise exposure and age, to compare the study groups with variables related to sociodemographic data, use of alcohol, tobacco and other psychoactive substances and hearing health. METHODS: Cross-sectional study, men aged between 30 to 50 years, with a negative history of exposure to occupational noise; normal ENT examination, included in two groups: patients with previous use of alcoholics and dysfunctional individuals who had never used dysfunctional alcoholics. Submitted the questionnaire for data collection, otolaryngologic and audiometric. RESULTS: significant differences between the two groups for the variables: education level (p=0,007), pay (p=0,039) and presence of hearing loss typical for ototoxicity (p=0,002). 87,5% of hearing losses in the group of alcoholics were typical loss for ototoxicity, while this rate was only 25,0% among individuals who had never used dysfunctional alcoholics. The variables that showed significant difference in the presence of typical hearing loss for ototoxicity were use-in-life drugs (p=0,017), use-on-life tobacco (p=0,000), reported hearing difficulty (p=0,00), tinnitus (p=0,004) and attendance at religious services (p=0,034). In the process of logistic regression, the final regression model indicated that prior use of dysfunctional alcohol increased the risk by 990% and use-of-life in tobacco increased the risk by 702%. CONCLUSIONS: The results support the evidence that the use of dysfunctional alcoholics are able to unleash the typical hearing loss ototoxicity.

This study aimed to investigate the effectiveness of the Quiet earplug noise protectors worn by a group of South African industrial workers exposed to excessive noise in the workplace. This was achieved by investigating the prevalence and amplitudes of distortion product otoacoustic emissions (DPOAEs), as they have been found to be sensitive to the effects of noise on the cochlea (Vinck, Van Cauwenberge, Leroy,&Corthals, 1999, p. 52). DPOAEs were recorded before and after noise exposure and were compared in order to determine whether the earplugs are providing sufficient protection against cochlear damage. DPOAEs were recorded using a test protocol where the primaries are fixed at L1 = 60dB SPL and L2 = 35dB SPL (L1 - L2 = 25dB) with an f2/f1 ratio of 1.18. The f2 frequencies were selected to correspond closely to the audiometric test frequencies of 2000Hz, 3000Hz, 4000Hz, 6000Hz and 8000Hz. The study found the prevalence of DPOAEs to be statistically stable and repeatable. This was true for DPOAEs measured successively during the same test sitting, as well as comparing prevalence determined before and after exposure to eight hours of noise. DPOAE prevalence alone was therefore not found to be a good indication of the temporary threshold shift (TTS) associated with the effects of noise on the cochlea. However, a significant finding of the study was that normal DPOAEs were recorded in only six right ears (24%) and seven left ears (28%) before noise exposure, even though all the subjects presented with hearing thresholds better than 25dB SPL. This may mean that cochlear pathology is already evident in some of the subjects tested. Further results of the study showed DPOAE amplitudes to be sensitive to the negative effects of excessive noise, as there was a significant difference between DPOAE amplitudes measured before and after the noise exposure. DPOAE amplitudes, specifically in the frequencies that are known to be affected by noise such as 4000Hz and 6000Hz, measured after the work-shift were significantly smaller than those measured before exposure to noise. Although correct usage of the earplugs could not be controlled for the duration of the noise exposure, each subject was instructed on the correct usage of the hearing protection before entering the noise zone. Bearing this limitation of the study in mind, because DPOAE amplitudes were reduced the implication is that the Quiet earplugs are not providing sufficient protection against the harmful effects of noise. / Dissertation (M (Communication Pathology))--University of Pretoria, 2005. / Speech-Language Pathology and Audiology / Unrestricted

Noise induced hearing loss has been extensively researched and commented on, yet it remains prevalent among industrial workers. The real-world attenuation properties of the Noise Clipper® custom-made hearing protection device and the comfort levels it afford are unknown. Furthermore, research in hearing conservation is seldom focused on the critical/biological thresholds for temporary threshold shift. Field studies on hearing protection devices have demonstrated that laboratory derived measures bear little relation to attenuation achieved in workers. Research has consistently demonstrated that noise reduction ratings that are derived from the laboratory real-ear-at-threshold method do not accurately represent the attenuation of noise that these devices actually provide and the matter remains unclear. Too many important variables are neglected in current real-ear-atthreshold evaluation protocols. This study used an alternative method, the microphone-inreal- ear approach where a dual-element microphone probe was inserted into the Noise Clipper® to measure noise reduction by recording the difference in noise levels outside and behind the device. The sub aims of the study were to record ambient noise levels and frequency spectra; to determine the attenuation characteristics; and to compare the attenuation thresholds to biological thresholds for temporary threshold shift. Using this protocol, measurements were made on 20 subjects in real world situations in order to match the attenuation characteristics of the Noise Clipper® to the actual noise exposure. The microphone-in-real-ear derived attenuation thresholds were compared to the real-earat- threshold values provided by the manufacturer of the Noise Clipper®. Additional subaims were to determine the comfort levels of the Noise Clipper® and record the selfreported wearing time of the device. Wearing comfort was evaluated using a bipolar rating scale. The researcher interviewed 240 mine workers at a platinum mine. Several comfort related sub-scales were used to quantify reported comfort levels. Simultaneously, usage time of the device was self-reported by each worker. Results of the microphone-in-real-ear measurements indicated that ambient noise levels fluctuated from day to day. The attenuation results indicated that most of the measurements suggested protection against noise induced hearing loss through the use of the Noise Clipper®. It was found that the REAT results over estimated the attenuation ability of the Noise Clipper® when compared to the results of the F-MIRE measurements. Eighty seven percent of the measurements indicated protection from thresholds below the biological threshold for temporary threshold shift. Seventy five percent of the workers indicated that the Noise Clipper® was comfortable to wear and 79% indicated that they used it for a full eight hour shift. The results provide an opportunity to assess the use of a protection device and its effectiveness among mineworkers combined with information regarding noise exposure levels. The findings highlight the importance of evaluating variability in terms of individual-specific protection. / Dissertation (MCommunication Pathology)--University of Pretoria, 2013. / Speech-Language Pathology and Audiology / unrestricted

Two of the primary occupational health threats to employees in the mining industry are noise-induced hearing loss (NIHL) and occupational lung diseases (OLD) with Tuberculosis (TB) included in the latter. The objective of this study was to investigate the hearing profile of a group of gold miners with and without TB to determine the effect of TB and its associated risk profile on hearing. Workers in AngloGold Ashanti mine in South Africa were recruited due to the fact that they present with these two health threats namely NIHL and TB. The audiological and medical surveillance data of 2698 subjects (between the years 2001 and 2009) were used in analyses. Hearing thresholds for the air conduction frequencies (0.5, 1, 2, 3, 4, 6, 8 KHz) in both ears were analysed in conjunction with biographic and occupational data. Subjects were divided into three groups, two experimental groups (Single TB treatment, n= 911 and Multiple TB treatment, n= 376) and one control group (n= 1411). A highly significant difference (p<0.01) was noted between the control group and both TB treatment groups across most frequencies and hearing parameters analysed, although the higher frequencies were more affected. Pair wise comparisons revealed the largest differences in hearing thresholds throughout between the control group and the multiple TB treatment groups. The smallest differences in hearing thresholds were evident between the two TB groups with the multiple TB treatment group presenting with the poorest thresholds. TB and its related risk profile had a pronounced influence on the decline of hearing thresholds. Thresholds for the multiple TB treatment group indicated more deterioration than the hearing thresholds of the single TB treatment group. This may point to the possibility that the influence of repeated TB on the subjects’ hearing thresholds over time was more pronounced than a single incidence of TB. It is still necessary however to separate the effects of the disease from the effects of the treatment on hearing. / Dissertation (MCommunication Pathology)--University of Pretoria, 2012. / Speech-Language Pathology and Audiology / Unrestricted

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Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: An investigation was undertaken to ascertain whether there could be a connection between noise levels in a dental environment and noise induced hearing loss (NIHL) in a sample of South African dentists. This took the form of a questionnaire sent to dentists in the Central Gauteng and Cape Western areas, followed by the measurement of noise emissions of airotor / air-turbine handpieces. / AFRIKAANSE OPSOMMING: 'n Ondersoek is geloods om te bepaal of daar 'n verband bestaan tussen die geraas vlakke in 'n tandheelkundige omgewing en Geraas Geïnduseerde Gehoor Verlies ("Noise Induced Hearing Loss") in 'n groep Suid-Afrikaanse tandartse. Die ondersoek het bestaan uit 'n vraelys wat tandaartse in Sentraal Gauteng en die Wes Kaap voltooi het, opgevolg deur die meting of registrasie van geraas vlakke veroorsaak deur lugturbine handstukke.