Objective: To investigate hearing loss among perinatally HIV-infected (PHIV+) adolescents on antiretroviral therapy (ART), and HIV-non-infected (HIV-) adolescents in Cape Town, South Africa. Methods: A cross-sectional analysis was carried out to describe the prevalence, nature and predictors (demographic, past medical history, clinical findings) of hearing loss in adolescents between 9 and 14 years of age. Screening pure-tone air-conduction (AC) thresholds above 30 decibels (dB) were considered to be indicative of debilitating hearing loss. Statistical analysis included univariate analysis and multivariate logistic regression. Results: The cross-sectional analysis included data from 540 participants; consisting 273 males (51%), 267 females, 432 PHIV+ and 108 HIV-, with a median age of 12 years. Hearing impairment was observed in 19% of all the adolescents in the study. Multivariate analysis showed the following predictors for any hearing loss: an unmarried primary caregiver (odds ratio (OR) 0.59; 95% confidence interval (CI), 0.39;0.91, p = 0.015), being female (OR 1.67; 95% CI, 1.12;2.51; p = 0.013) and reports of being troubled by ear pain or discharge in the last month (OR 2.54; 95% CI, 1.55;4.17; p = <0.001) after adjustment. Univariate analysis showed an association between hearing loss and a longer duration on ART among PHIV+ adolescents (OR 1.80, 95%CI 1.17;2.75, p = 0.007). Conclusion: The prevalence of hearing loss appears to be comparable between PHIV+ and HIVadolescents in Cape Town. In low resource settings, a history of ear pain or discharge within the last month may be used as a screening tool for a hearing assessment, and guide referral for formal hearing tests.

The phenomenon of residual inhibition, whereby the phantom sensation of tinnitus is suppressed following the presentation of a masking stimulus, has significant implications for understanding the neural basis of tinnitus itself. By using novel psychoacoustic techniques and three computer-based tools developed and applied specifically to measure tinnitus sensation and residual inhibition, a pattern emerges in which the depth and duration of tinnitus suppression relates to the center frequency of the band-passed noise masking stimulus. A correspondence between the region of hearing loss, the tinnitus spectrum and the masking stimuli most effective in suppressing tinnitus is revealed. These results suggest that cortical reorganization observed in animal models of tinnitus is not the principal basis of tinnitus, and provide a baseline for optimizing residual inhibition in individual cases and for further experiments. / Note: Pages 17-23 in this thesis were replaced with a citation due to copyright issues. / Thesis / Master of Science (MSc)

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

No description available.

A deficiência auditiva constitui uma importante categoria de defeitos congênitos que podem se manifestar isoladamente ou fazer parte do espectro fenotípico de várias síndromes. O presente trabalho refere-se ao estudo genéticoclínico de pacientes portadores de deficiência auditiva não sindrômica, com os objetivos de estabelecer a razão sexual, tipo, grau, simetria, lateralidade e progressão da deficiência auditiva; determinar diagnósticos etiológicos prováveis da deficiência auditiva, estabelecendo, quando possível, o padrão de herança genética e fornecer meios para o aconselhamento genético. Foram avaliados 306 pacientes no serviço de Genética Clínica do Centro de Atendimento aos Distúrbios da Audição, Linguagem e Visão do Hospital de Reabilitação de Anomalias Craniofaciais-USP, no período de dezoito meses. Dos 306 pacientes avaliados, 278 eram portadores de deficiência auditiva, 27 portadores de distúrbio de linguagem e 1 portador de deficiência visual. De acordo com o critério estabelecido (presença de deficiência auditiva isolada), 144 pacientes foram selecionados para este estudo, através da história clínica, história familial, dados pré, peri e pós-natais e audiometria (dados de prontuário). A análise estatística não mostrou associação significativa entre a ocorrência de deficiência auditiva não sindrômica e o sexo dos propósitos. Dos 144 pacientes estudados, 95.8% dos casos tinham etiologia genética e 4.2% etiologia ambiental. Nos portadores de deficiência auditiva de etiologia genética, o padrão de herança indefinido (53.6%) foi o mais freqüente, seguido o de herança autossômica recessiva (23.9%) e autossômica dominante (22.5%); as anomalias maiores e menores associadas à deficiência auditiva não estavam relacionadas com esta deficiência. O tipo de perda auditiva predominante foi o neurossensorial (99.3%) e deficiência auditiva severa a profunda foi a mais freqüente (34.8%). Da amostra, 68.1% dos casos apresentaram perda auditiva pré-lingüística, 54.9% apresentaram perda auditiva assimétrica, 95.8% perda auditiva bilateral e 95.1% perda auditiva não progressiva. O estudo permitiu concluir que história clínica e familial são informações importantes no diagnóstico etiológico da deficiência auditiva; que as configurações da curva audiométrica são avaliações de apoio ao esclarecimento diagnóstico da deficiência auditiva; que o aconselhamento genético é dificultado nos casos com padrão de herança indefinido e que análises moleculares são dados subsidiários à definição etiológica da deficiência auditiva. / Hearing loss constitutes an important category of congenital defects that can be expressed isolately or making part of the phenotypical spectrum of several syndromes. The aim of this study is to establish the sex-ratio, type, degree, symmetry, laterality, progression , and to find out the etiology of non syndromic hearing loss, establishing, when possible, the inheritance pattern providing ways to genetic couseling. During 18 months, 306 patients were evaluated at Centro de Atendimento aos Distúrbios da Audição, Linguagem e Visão of the Hospital de Reabilitação de Anomalias Craniofaciais-USP. Nonsyndromic hearing loss was observed in 144 of them; syndromic hearing loss in 134; only speech impairment in 27, and only visual impairment in 1. According criteria only the 144 patients with nonsyndromic were selected for this study. There were 83 females (57.6%) and 61males (42.4%); genetic etiology was found in 95.8% of the sample and environmental etiology in 4.2%; major and minor associated anomalies were not related with hearing loss. Sensorineural hearing loss was found in 99.3% and severeprofound hearing loss was the most frequent (34.8%). Others results were: asymmetrical hearing loss in 54.9%, bilateral hearing loss in 95.8%, and non progressive in 95.1%. This study allow to conclude that the familial and clinical data were important to define etiological diagnosis; the shape of audiograms were evaluations that help to clarify, but not define, the diagnosis. Genetic counseling is difficult when the pattern of inheritance is unknown; and molecular studies are important subsidiary test to define the etiology of the hearing loss.

A deficiência auditiva constitui uma importante categoria de defeitos congênitos que podem se manifestar isoladamente ou fazer parte do espectro fenotípico de várias síndromes. O presente trabalho refere-se ao estudo genéticoclínico de pacientes portadores de deficiência auditiva não sindrômica, com os objetivos de estabelecer a razão sexual, tipo, grau, simetria, lateralidade e progressão da deficiência auditiva; determinar diagnósticos etiológicos prováveis da deficiência auditiva, estabelecendo, quando possível, o padrão de herança genética e fornecer meios para o aconselhamento genético. Foram avaliados 306 pacientes no serviço de Genética Clínica do Centro de Atendimento aos Distúrbios da Audição, Linguagem e Visão do Hospital de Reabilitação de Anomalias Craniofaciais-USP, no período de dezoito meses. Dos 306 pacientes avaliados, 278 eram portadores de deficiência auditiva, 27 portadores de distúrbio de linguagem e 1 portador de deficiência visual. De acordo com o critério estabelecido (presença de deficiência auditiva isolada), 144 pacientes foram selecionados para este estudo, através da história clínica, história familial, dados pré, peri e pós-natais e audiometria (dados de prontuário). A análise estatística não mostrou associação significativa entre a ocorrência de deficiência auditiva não sindrômica e o sexo dos propósitos. Dos 144 pacientes estudados, 95.8% dos casos tinham etiologia genética e 4.2% etiologia ambiental. Nos portadores de deficiência auditiva de etiologia genética, o padrão de herança indefinido (53.6%) foi o mais freqüente, seguido o de herança autossômica recessiva (23.9%) e autossômica dominante (22.5%); as anomalias maiores e menores associadas à deficiência auditiva não estavam relacionadas com esta deficiência. O tipo de perda auditiva predominante foi o neurossensorial (99.3%) e deficiência auditiva severa a profunda foi a mais freqüente (34.8%). Da amostra, 68.1% dos casos apresentaram perda auditiva pré-lingüística, 54.9% apresentaram perda auditiva assimétrica, 95.8% perda auditiva bilateral e 95.1% perda auditiva não progressiva. O estudo permitiu concluir que história clínica e familial são informações importantes no diagnóstico etiológico da deficiência auditiva; que as configurações da curva audiométrica são avaliações de apoio ao esclarecimento diagnóstico da deficiência auditiva; que o aconselhamento genético é dificultado nos casos com padrão de herança indefinido e que análises moleculares são dados subsidiários à definição etiológica da deficiência auditiva. / Hearing loss constitutes an important category of congenital defects that can be expressed isolately or making part of the phenotypical spectrum of several syndromes. The aim of this study is to establish the sex-ratio, type, degree, symmetry, laterality, progression , and to find out the etiology of non syndromic hearing loss, establishing, when possible, the inheritance pattern providing ways to genetic couseling. During 18 months, 306 patients were evaluated at Centro de Atendimento aos Distúrbios da Audição, Linguagem e Visão of the Hospital de Reabilitação de Anomalias Craniofaciais-USP. Nonsyndromic hearing loss was observed in 144 of them; syndromic hearing loss in 134; only speech impairment in 27, and only visual impairment in 1. According criteria only the 144 patients with nonsyndromic were selected for this study. There were 83 females (57.6%) and 61males (42.4%); genetic etiology was found in 95.8% of the sample and environmental etiology in 4.2%; major and minor associated anomalies were not related with hearing loss. Sensorineural hearing loss was found in 99.3% and severeprofound hearing loss was the most frequent (34.8%). Others results were: asymmetrical hearing loss in 54.9%, bilateral hearing loss in 95.8%, and non progressive in 95.1%. This study allow to conclude that the familial and clinical data were important to define etiological diagnosis; the shape of audiograms were evaluations that help to clarify, but not define, the diagnosis. Genetic counseling is difficult when the pattern of inheritance is unknown; and molecular studies are important subsidiary test to define the etiology of the hearing loss.

No description available.

This purpose of this study was to examine pragmatic differences in children with hearing loss compared to children without hearing loss by understanding use of communication repairs, self and peer attitudes and perceptions to suggest the most appropriate intervention approaches. Previous research has found use of communication repairs, self and peer perceptions and attitudes to be associated with pragmatic skills. Intervention approaches were suggested for remediating pragmatic differences in children with hearing loss. / text

Hearing loss is a disability that affects thousands of people in the world. It is estimated that there is 400,000 people with hearing difficulties in New Zealand (New Zealand Audiological Society, 2007). People with hearing loss have the right to access to information and communication (United Nations Enable, 2003). Without access to information and communication, the hearing impaired may encounter problems with emotional and social functioning, and consequently suffer with decreased quality of life. Clinical experience and investigations have revealed success with assistive listening devices (ALDs) where use of hearing aids has been unsuccessful. ALDs are devices that improve the communication function for the hearing impaired. ALDs can be used with or without hearing aids to overcome the negative effects of poor room acoustics. Currently, in the literature, little is known about the use and maintenance of ALDs in community organizations. This study investigates the use and maintenance of ALDs in the Christchurch community of New Zealand. A list of community organizations that provide ALDs to the public of Christchurch was also made available to individuals who have hearing impairment. The study found there is a lack of ALDs within the Christchurch community. Also that current ALD technology within the Christchurch community is not necessarily compatible with current hearing aid technology and that most organizations rely too heavily on PA systems. PA systems do not necessarily meet the needs of the hearing impaired and an ALD specifically targeting their hearing loss would improve their speech perception. Community organizations are not advertising enough that they offer ALDs which adds to the lack of awareness in Christchurch. Results found that most ALDs in the Christchurch community are in working order, however, there is a need for organizations to be educated about their use and maintenance. Audiologists and other health professionals have a key role in providing appropriate recommendations in the use and benefits that ALDs have on speech perception. These will directly improve the listening situations that the hearing impaired have throughout their communities, thus improving their quality of life.

M.P.H.(Occupational Hygiene), Faculty of Health Sciences, University of the Witwatersrand, 2009 / BACKGROUND Hearing loss from occupational exposures is a serious and widespread problem in underground nickel mining. This is a major contributor to compensable illnesses resulting not only in costly compensation but posing a serious threat to safety and also reducing the quality of working life. OBJECTIVES The objectives of this study were to identify the prevalence of noise induced hearing loss amongst underground nickel miners with at least 5 years of exposure as well as describe some risk factors for noise induced hearing loss in this occupational setting. METHODS One hundred and sixty eight underground nickel miners, or one hundred percent of eligible workers’ medical records with baseline and periodic audiograms were reviewed to identify the prevalence of noise induced hearing loss and also evaluate some of the risk factors for noise induced hearing loss namely age, duration of exposure, use of oto-toxic agents, high ambient noise levels, hearing impairment, high pre-employment noise levels, history of acoustic trauma, history of ear injury and history of previous military, hunting or police work. One hundred underground mine workers were interviewed to give insight into their pre-employment noise exposure history, non-occupational noise exposure, perceived noise levels at work, knowledge of noise hazards and their control, and the use of hearing protection devices. One hundred and sixty eight workers were observed in their various tasks over a 14 day period and their work practices were scored to identify compliance to the use of hearing protective devices as well as confirm the presence or absence of oto-toxic agents like heavy metals and solvents. Data were analyzed using the EpiInfo software version 3.4.3: 1997 as well as the online statistical package Vassar Stats. RESULTS A noise induced hearing loss prevalence of 27.4% was identified with 42% being mild hearing loss, 28.8% moderate hearing loss and 28.8% moderate to severe noise induced hearing loss. The highest noise induced hearing loss prevalence of 60% was found in the 50 and above years age group whilst 45.5% was found in the 40 – 49 year age group, 20% in the 30- 39 year age group and 5.3 % in the 20 – 29 year age group. This difference was statistically significant ( 2 1 = 19 p < 0.001). Age with a 2 = 24, p< 0.002 and duration of exposure with a 2 = 19, p< 0.001 were found to be major determinants of noise induced hearing loss at the mine. Jackhammer operation and machine operation were found to be associated with noise induced hearing loss compared to the other tasks; Tukey’s Honestly Significant Difference 0.05 = 12.23 p<0.01. The following risk factor was found to be related to noise induced hearing loss: use of quinine OR = 2.16 with CI 95% = 0.12 – 1.72. Ninety seven percent of the workers confirmed exposure to high noise levels. The knowledge of noise induced hearing loss at the mine was high (85%). Compliance with the use of hearing protective devices was found to be low with optimum usage only being achieved during the last 4 days of the 14 day observation period. CONCLUSIONS These findings attest to the relatively high prevalence of noise induced hearing loss at the mine. It can also be concluded that though the knowledge of noise induced hearing loss is high, the effective use of hearing protection still needs improvement through the implementation of comprehensive hearing conservation programs which adequately screen workers at pre-employment stage as well as consider the workers’ perceived knowledge, attitudes as well as practices in an occupational setting.