MPH, Occupational Hygiene, Faculty of Health Sciences, University of the Witwatersrand / Introduction Locomotive operators in the mining industry are exposed to high levels of noise and vibration. There is currently limited information indicating whole-body vibration exposure levels conducted over an 8-hour time weighted average (TWA) exposure period; most of the available data are based on instantaneous measurements. The 10-Ton New Era locomotive was specifically designed with the focus on areas such as ergonomics, safety, future automation, productivity and flexibility of use. The locomotive has a single cab and can be driven and controlled with maximum visibility in the direction of travel. Most mining houses are converting from the use of the 10 Ton Goodman battery operated locomotive to the 10Ton New Era locomotive, hence the focus of noise and vibration measurements on the latter. Objectives This research report documents a project to measure noise and whole-body vibration exposure levels of locomotive operators working in an underground platinum mine. The objectives of the study are: • to describe the eight hour time weighted average occupational noise exposure levels of locomotive operators operating the 10-Ton New Era locomotive in an underground platinum mine over 2008 and 2009; • to describe personal whole-body vibration exposure levels of locomotive operators operating the 10-Ton New Era locomotive in an underground platinum mine over 2008 and 2009; and 5 • to determine whether personal noise and whole-body vibration exposure levels of locomotive operators operating the 10-Ton New Era locomotive in an underground platinum mine over 2008 and 2009 comply with national and international standards. Methods Personal noise and whole-body vibration exposure measurements were obtained from 21 underground locomotive operators. Measurements were conducted in accordance with the procedures described in the SANS 10083 standard for personal noise dosimetry and the ISO 2631-1 standard for whole-body vibration. Determination of likely health risks for the operators were based on a comparison of the measured time-weighted noise exposure levels with the South African OEL and the ACGIH threshold limit value; whole-body vibration levels were compared with the HGCZ limits presented in Annex B of the ISO 2631-1 standard and the EU directive daily exposure limits. Results The measured noise and whole-body vibration levels taken over an 8-hour TWA exposure period were higher when compared to national and international standards. The mean LTWA levels for noise was 66.5 dB(A) with 12.5% of the measurements exceeding the South African OEL of 85dB(A). 45% of the wholebody vibration measurements fell within the HGCZ indicating that whole-body vibration exposure on locomotive operators presents a moderate probability for an adverse health outcome. Discussion and Conclusion Locomotive operators are exposed to potentially harmful levels of noise and whole-body vibration. The Mine Health and Safety Act requires an employer to assess the health and safety risks that hazards pose to their employees, and to take reasonably practicable steps towards eliminating or controlling those risks. Like any other risks at a workplace, noise and whole-body vibration needs to be 6 identified and controlled, and the approach to be taken is one of a risk management

This thesis is focused on the legal protection of the environment and human health from the effects of selected physical factors, especially noise, vibration and ionizing and non- ionizing radiation. In the introduction the thesis defines the every singe physical factor, reminds their effects on the environment and the health and life of humans and especially suggests possible measures to eliminate the negative effects of these factors. The emphasis is placed on clarifying the consistency of these measures with the means of protection. Subsequently, the thesis includes separate chapters devoted to European, Czech and selected international legal instruments of protection from selected physical factors and their comparison. One of the key questions to be dealt in the thesis is the effort to clarify whether and how does the legislation in different countries exploit physical similarity between the studied factors. Another question to answer is to what extent is it (for the effective protection of the environment, life, health and other values) useful to accurately identify and name the sources of threat, and whether the case-focused legal protection, anchoring extensively detailed rules for each previously known source of threat, actually leads to more efficient protection against various sources of risk. It...

Cette thèse s'inscrit dans le cadre de la recherche des moyens de réduction du bruit. Le but est d’analyser et de créer par une méthode passive, le confinement d’énergie acoustique dans les irrégularités géométriques via le phénomène de localisation pour ensuite la dissiper. En prélude à l'atténuation du bruit par les géométries irrégulières, les mécanismes de la dissipation acoustique sont rappelés et illustrés par quelques exemples de réseaux de résonateurs quart-d'onde. Le phénomène de localisation est ensuite étudié par une analyse modale. Le caractère localisé d'un mode est quantifié par son volume d'existence relatif (VER) qui donne, en fraction du volume total du domaine, le volume effectif concerné par l'énergie du mode. Il ressort de cette étude que seules les cavités irrégulières ayant des irrégularités en forme de sous-cavités couplées à une cavité principale sont « localisantes ». La fréquence d'un mode localisé est liée aux dimensions de la zone irrégulière de localisation. Le lien entre les irrégularités géométriques et la dissipation acoustique est ensuite analysé au moyen des indicateurs tels que le facteur de qualité, le coefficient d'absorption ou le taux d'amortissement de l'énergie. Cette étude montre que les cavités irrégulières amortissement mieux une onde acoustique comparativement aux cavités à géométrie régulière. Toutefois, la dissipation de l'énergie acoustique des cavités irrégulières n'est pas uniquement liée à la localisation. Elle dépend également d'autres paramètres (porosité, résistivité, etc.). Lorsque les irrégularités des parois rigides ne permettent pas de réaliser une dissipation suffisante, elles peuvent être réalisées dans les matériaux poroélastiques à performance acoustique moyenne pour augmenter leur capacité dissipative. Enfin, des études expérimentales menées ont permis de valider l'existence du phénomène de localisation et de confirmer la tendance plus dissipative des géométries irrégulières par rapport aux géométries régulières. De même, des mesures du coefficient d'absorption d'un échantillon de forme préfractale d'un béton de chanvre (matériau ayant une performance acoustique moyenne) montrent une augmentation de la dissipation de plus de 40% induite par la forme irrégulière. La contribution majeure de cette thèse est d’avoir répondu à un défi technologique important consistant à effectuer une mise en évidence expérimentale du phénomène de localisation jusque-là difficile à réaliser avec des microphones. Pour y parvenir, un outil optique peu conventionnel dans la métrologie acoustique est adopté; il s'agit de la réfracto-vibrométrie qui consiste à utiliser, sous certaines conditions, le vibromètre laser pour mesurer un champ acoustique (pression acoustique). Bien que contraignante, cette technique présente l'avantage d'être non intrusive et donc moins encombrante même pour de petites cavités comparativement aux microphones. / In this thesis, the acoustical behavior of irregular cavities leading to localization phenomenon is investigated for noise reduction applications. The aim of this work is to study and create by means of passive method, an accumulation of acoustical energy and dissipate it. Before addressing geometrical irregularities effects on the sound field, viscothermal dissipation mechanisms of sound are recalled and illustrated through few networks of quarter-wave resonators. In a second part, a study of the localization phenomenon is carried out by a modal analysis approach. The localization is quantified by the relative existence volume (VER), an indicator which gives a measure of the volume of the region in which a mode is localized as a fraction of the total cavity volume. The localization analysis is conducted using both regular and irregular cavities. It has been shown that only cavities with irregular geometry, such that sub-cavities are formed, can localize some acoustical modes. Moreover, the frequency of a localized mode is related to the dimensions of the localization region. Following the investigation of the localization phenomenon, the relation between cavities geometry and sound energy dissipation has been studied by the estimation of damping indicators, such as the quality factor, the sound absorption coefficient or the energy damping rate. According to this study, irregular cavities have higher capability to damp sound waves compared to regular cavities. However, for the case of irregular cavities only, the induced dissipation is not proportional to the localization. Nevertheless, when irregularities of rigid walls are not able to achieve sufficient dissipation, this can be obtained with slightly absorptive porous materials of irregular geometry. In fact, the dissipative properties of some porous materials can be optimized by giving them irregular interface. Finally, an experimental set-up has been designed to validate the localization phenomenon and to confirm the damping tendency of irregular geometries in comparison to regular ones. Moreover, measurements of the sound absorption coefficient of a hemp concrete reveal that the sample of irregular geometry achieves sound dissipation more than 40% higher than the one achieved by a regular plane sample. Finally, this thesis has addressed a technological challenge consisting of experimentally validating the localization phenomenon which is so far very difficult to obtain by the use of conventional pressure microphones. In the framework of this thesis, an optical non-conventional sound pressure measurement technique has been used. The used technique is the laser refracto-vibrometry which consists of using a laser vibrometer in some specific conditions to measure the acoustical field (sound pressure). This technique is difficult to conduct but it has the advantage of being contactless, thus less cumbersome for even very small cavities as compared to pressure microphones.

Orientador: Jozué Vieira Filho / Banca: Suely Cunha Amaro Mantovani / Banca: Marco Aparecido Queiroz Duarte / Resumo: A redução de ruído em sinais de voz é importante nos mais variados contextos. Dentre as diferentes técnicas encontradas na literatura, a maioria tem como base o processamento no domínio da frequência, com implementações via Transformada de Fourier. A fase do sinal processado é, nesses casos, a própria fase do sinal ruidoso. Neste trabalho, o objetivo é avaliar os efeitos da fase do sinal limpo no processamento. Para tal, foram feitos testes utilizando métodos eficientes de redução de ruído em sinais de voz, tendo como base a Subtração Espectral e a Minimização do Erro Quadrático Médio, implementados usando a relação sinal/ruído a priori. Os resultados mostram que a fase é importante e altera a qualidade do sinal processado, abrindo caminho para novas técnicas de redução de ruído / Abstract: The noise reduction in speech signals is important in various contexts. Among the various techniques in the literature, most of them are based in the frequency domain, with implementation through Fourier transform. The phase of the processed signal is, in these cases, the actual phase of the noisy signal. In this work, the objective is to evaluate the effects of the phase in the processing. To this end, tests were made using efficient methods of noise reduction in speech signals, based on the Spectral Subtraction and Minimizing the mean square error, implemented using the a priori signal/noise ratio. The results show that phase is important and changes the quality of the processed signal, opening studies to new techniques for noise reduction / Mestre

Os objetivos deste trabalho foram: avaliar os efeitos das diferentes relações sinal/ruído, no reconhecimento da fala com o implante coclear; comparar o reconhecimento da fala no ruído, com diferentes tipos de implantes cocleares multicanais; avaliar a influência do tempo de surdez, tempo de uso do implante coclear e progressão da surdez, no reconhecimento da fala com o implante coclear e avaliar o grau de dificuldade dos usuários de implante coclear, em situações com ruído competitivo no dia-a-dia. Foram selecionados 40 adultos com deficiência auditiva pós-lingual, com os implantes cocleares Nucleus 22 (N=13, estratégia SPEAK), Nucleus 24 (N=7, estratégia ACE), Combi 40 (N=6), Combi 40+ (N=7) e Clarion (N=7) com a estratégia CIS, com experiência de mais 6 meses de uso do implante coclear e reconhecimento de fala em conjunto aberto. Foi avaliado o reconhecimento das sentenças CPA (Valente 1998), no silêncio e nas relações S/R de +15 dB, +10 dB, +5 dB e aplicado o questionário Social Hearing Handicap Index - SHHI (Wedel e Tegtmeier 1979, Wedel 1983), para a auto-avaliação do desempenho com o implante coclear, em situações de silêncio (componente da deficiência auditiva) e ruído (componente da seletividade), no dia-a-dia. Os usuários de todos os tipos de implante coclear apresentaram redução significativa dos índices de reconhecimento de sentenças CPA, em função da diminuição da relação S/R, com a curva das medianas de reconhecimento das sentenças CPA alcançando 50% na relação S/R de +10 dB. Não houve diferença estatisticamente significante nos índices de reconhecimento das sentenças CPA e escores de dificuldade do Social Hearing Handicap Index (SHHI), obtidos com os diferentes tipos de implantes cocleares e estratégias de codificação da fala. As dificuldades dos usuários de implante coclear foram raras nas situações de silêncio (componente da deficiência auditiva) e ocasionais nas situações com ruído competitivo (componente da seletividade), no questionário SHHI. Observou-se, também, a influência das características dos sujeitos (tempo de surdez, tempo de uso do implante coclear e progressão da surdez) nos índices de reconhecimento das sentenças CPA. O presente estudo permitiu concluir que os usuários de todos o tipos de implante coclear multicanais apresentaram redução dos índices de reconhecimento da fala, em função da diminuição da relação S/R e maior dificuldade, no dia-a-dia, em ambientes com ruído competitivo, do que no silêncio. / The aims of this study were: to evaluate the effects of different signal to noise ratios on speech recognition obtained by the use of the cochlear implant; to compare the speech recognition in noise with different types of multichannel cochlear implants; to evaluate the influence of duration of deafness, time of implant use and hearing loss progression in the speech recognition with cochlear implant and to evaluate the degree of difficulty for speech understanding in noise in daily life situations as well. Forty adults with post lingual hearing loss implanted with Nucleus 22 (n=13, SPEAK strategy), Nucleus 24 (n=7, ACE strategy), Combi 40 (n=6, CIS strategy), Combi 40+ (n=7, CIS strategy) and Clarion (n=7, CIS strategy). The minimum time of implant use was 6 months. All subjects enjoyed some degree of open set recognition. It was evaluated the recognition for CPA sentences (Valente 1998), in silence and in S/N +15, +10 and +5 dB. It was also applied the Social Hearing Handicap Index - SHHI questionnaire (Wedel e Tegtmeier 1979, Wedel 1983) for self assessment in daily life in silence (hearing loss component) and noise (selectivity component). All the implanted adults presented a significant reduction in the scores for sentences recognition as the S/N decreased. The medians´ curve for sentence recognition reached 50% in the signal to noise ratio of +10 dB. There was no difference statistically significant in sentences recognition scores and difficulty scores obtained with the Social Hearing Handicap Index (SHHI), for all types of implants and different speech strategy. The difficulties of implanted adults were rare in silence (hearing loss component) and occasional in noisy situations (selectivity component) in the SHHI questionnaire. It was also observed the influence of duration of deafness, time of implant use and hearing loss progression in the sentences recognition scores. In this study it was concluded that all subjects presented a significant reduction in sentences recognition scores as the S/N decreased and all subjects showed more difficulty for speech understanding in noisy environments independently of the type of multichannel cochlear implants used.

A dissertação Pintura, silêncio e outros ruídos tem como principal mirada reflexiva a produção de dois artistas norte-americanos: John Cage e Cy Twombly. Partindo das proposições de entendimento do conceito de silêncio feitas por John Cage, Pintura, silêncio e outros Ruídos tensiona algumas aproximações entre determinados trabalhos de Cage - produzidos a partir de 4\'33, 1952 - e da produção em pintura e desenho de Twombly, sugerindo algumas relações entre som, desenho, pintura e ruído. As reflexões geradas a partir da aproximação entre os dois artistas são levadas, em seguida, à minha própria produção em pintura, observando a maneira como incidem em minha investigação prática. / The dissertation Painting, silence and other noises has as its main focus of reflection the work of two north-american artist: John Cage and Cy Twombly. Following along the understanding propositions of the concept of silence done by John Cage, Painting, silence and other stresses some similarities between some (specific) work done by Cage - fr 4\'33? and beyond - and both pantings and drawings by Twombly, suggesting some relationship between sound, drawing, painting and noise. The reflections generated from the proximity between the two artists are considered, as follows, in my own production of paintings, noting how they influence my own research.

Au cours des dernières décennies, l’industrie de la micro-électronique a connu une large démocratisation de l’utilisation des applications de télécommunication. L’amélioration des procédés de conception et de fabrication ont permis de produire des circuits analogiques, mixtes et radiofréquences complexes et hautes performances pour ces applications. Toutefois, le coût de test de ces circuits intégrés représente encore une large part du coût de fabrication. En effet, très souvent, tester des fonctions analogiques ne se résume pas à un test fonctionnel mais signifie mesurer les spécifications du circuit. Ces mesures nécessitent l’utilisation d’instruments dédiés bien plus couteux que les ressources numériques disponibles sur un équipement de test industriel standard. Une des spécifications essentielle mais couteuse à caractériser pour les circuits RF est le niveau de bruit de phase. La technique actuellement utilisée en industrie consiste à capturer le signal à l’aide d’un canal testeur analogique équipé d’un convertisseur analogique-numérique hautes performances ; une transformée de Fourier est alors appliquée sur le signal numérisé et le bruit de phase est mesuré sur le spectre résultant. L’approche proposée dans cette thèse consiste à réaliser la mesure de bruit de phase en n’utilisant que des ressources digitales faible coût. L’idée fondamentale consiste à réaliser la capture 1-bit du signal analogique avec un canal numérique standard et à développer des algorithmes de post-traitement dédiés permettant de retrouver l’information relative au bruit de phase à partir d’une évaluation des temps de passages à zéro du signal. Deux méthodes sont présentées. La première méthode est basée sur une estimation de la fréquence instantanée du signal et une analyse de la dispersion induite par le bruit de phase. Cette méthode impose une contrainte forte quant à la fréquence d’échantillonnage à utiliser et s’est révélée sensible au bruit d’amplitude, limitant la gamme de mesures possibles. Une seconde méthode est alors proposée afin de s’affranchir de ces limitations. A partir de la capture binaire du signal analogique, une reconstruction de la phase instantanée du signal est réalisée, puis filtrée puis caractérisée grâce à un outil usuel d’évaluation de stabilité fréquentielle : la variance d’Allan. Cette technique, robuste au bruit d’amplitude et au jitter, peut être paramétrée et permet une caractérisation efficace du bruit de phase sans contrainte fondamentale. En plus des simulations, ces techniques font l‘objet d’une étude stochastique et sont validées expérimentalement sur différents types de signaux à mesurer – générés artificiellement ou provenant de puces sur le marché – et avec différentes conditions mesures – sur oscilloscope ou sur testeur industriel, en laboratoire et en production –. Une implémentation sur puce est aussi proposée et validée avec un prototype sur FPGA. / In recent decades, the microelectronics industry has experienced a wide democratization of the use of telecommunication applications. The improved process design and manufacturing have produced complex and high performance analog, mixed and radio frequency circuits for these applications. However, the test cost of these integrated circuits still represents a large part of the manufacturing cost. Indeed, very often, analog testing is not just a functional test but needs measurements for specification validations. These measurements require the use of dedicated instruments expensive resources on standard industrial test equipment.One of the essential but costly specifications to validate in RF circuitry is the phase noise level. The currently used industrial technique consists in capturing the signal from the circuit under test using an RF tester channel equipped with a high performance analog to digital converter; a Fourier transform is then applied to the digitized signal and the phase noise is measured on the resulting spectrum.The approach proposed in this thesis is to achieve the phase noise measurement using solely digital low-cost resources. The basic idea is to perform 1-bit capture of the analog signal with a standard digital channel and develop post-processing algorithms dedicated for phase noise evaluation from the zero-crossings of the signal.Two methods are presented. The first method is based on an estimate of the instantaneous signal frequency and an analysis of their dispersion induced by phase noise. This method imposes a strong constraint on the sampling frequency to be used and proved to be sensitive to noise amplitude, limiting the range of possible measures. A second method is then proposed to overcome these limitations. From the binary capture of the analog signal, a reconstruction of the instantaneous phase of the signal is carried out, then filtered and characterized by a common tool of frequency stability assessment: the Allan variance. This technique, robust to amplitude noise and jitter, can be parametrized and enables efficient characterization of phase noise without fundamental constraint.In addition to the simulations, these techniques are subject to a stochastic study and are validated experimentally on different types of signals to be measured - artificially generated or from chips on the market - and with different measuring instruments - on oscilloscope or industrial tester, in laboratory and on a production line-. An On-chip implementation is also proposed and validated with a FPGA prototype.

O aumento expressivo nos níveis de ruído, principalmente nas áreas urbanas próximas aos aeroportos, tem contribuído de forma preocupante para os já elevados e atuais níveis de poluição sonora registrados nos grandes centros urbanos. Além do fato dos incômodos e desconfortos no cotidiano das pessoas provocados por esse fato, as autoridades que tratam desse assunto alertam para os danos causados a saúde humana e dos seres vivos em geral. Alguns países europeus que estudam este assunto se dizem preocupados com os impactos negativos em suas economias na questão do desequilíbrio orçamentário no setor da saúde. A tese motivada pela utilização ampla de barreiras acústicas no setor de transporte rodoviário, ferroviário convencional e de alta velocidade, e, prioritariamente aéreo, pôde construir por intermédio desses contextos o conhecimento necessário e um cenário de expectativas promissoras com o objetivo de colaborar com a atenuação do ruído aeronáutico com uma proposta acadêmica de implantação de barreiras acústicas articuladas posicionadas nas cabeceiras da pista principal do Aeroporto de Congonhas em São Paulo no momento da decolagem, tendo como paradigma conceitual e operacional o uso similar dos defletores de energia que são utilizados nos conveses dos porta-aviões no momento das suas decolagens. / The significant increase in noise levels, especially in urban areas close to airports, has contributed to the alarmingly high already and current noise pollution levels recorded in major urban centers. Besides the fact of annoyances and discomforts in the everyday life of people caused by this fact, the authorities dealing with this subject warn of the damage to human health and living creatures in general. Some European countries who study this issue claim to be concerned about negative impacts on their economies on the question of the budget imbalance in the health sector. Some European countries who study this issue claim to be concerned about negative impacts on their economies on the question of the budget imbalance in the health sector. The thesis motivated by wide use of noise barriers in the road transport sector, conventional and high-speed rail, and, as a matter of priority air could build through these contexts the knowledge necessary and a promising expectations scenario with the objective of collaborating with the aeronautical noise attenuation with an academic proposal to implement noise barriers at the headwaters of the track positioned hinged main from Congonhas Airport in Sao Paulo at the time of takeoff with the conceptual and operational paradigm using similar energy deflectors that are used on the decks of the carrier at the time of their landings.

Introdução: O ruído é um dos principais agentes de poluição ambiental, que em intensidades elevadas, poderá causar a perda auditiva induzida por níveis de pressão sonora elevadas (PAINPSE). A PAINPSE é o segundo tipo de perda auditiva neurossensorial mais frequente, e considerada uma das principais doenças ocupacionais. Para evitar os prejuízos da exposição ao ruído ocupacional, legislações determinam o monitoramento e o desenvolvimento de ações para reduzir os efeitos da exposição, sendo o uso de dispositivos de proteção auditiva (DPA) a mais empregada. Contudo é comum que o trabalhador relate dificuldades para se comunicar com o DPA, o que pode induzi-lo ao uso inadequado. Os estudos já realizados apresentam discordâncias sobre os efeitos do DPA para a inteligibilidade da fala, além de serem poucos os que compararam participantes com perdas auditivas com normo-ouvintes. Objetivos: Avaliar a inteligibilidade de fala em trabalhadores expostos a ruído durante o uso de DPA. Métodos: Trata-se de um estudo transversal, aprovado pelo Comitê de Ética em Pesquisa da instituição nº 130/14, com amostra de 36 participantes, todos do sexo masculino e expostos ao ruído. Foram divididos em grupo normo-ouvintes (G1), com 20 participantes e com perda auditiva (G2), com 16 participantes. Todos os participantes realizaram avaliação da inteligibilidade de fala em campo acústico, utilizando listas de monossílabas e sentenças, em situações de uso do DPA no silêncio e no ruído e sem o uso do DPA no ruído. Resultados: Na avaliação da inteligibilidade de fala com DPA utilizando as monossílabas, ambos os grupos apresentaram porcentagens de acertos superiores à 95% na situação de silêncio. Na presença do ruído com o DPA, não foi detectado efeito de interação envolvendo grupo (p>=0,106) e nem efeito de grupo (p=0,182), mas houve efeito de interação entre intensidade de fala e relação sinal/ruído (S/R) (p=0,006). Na avaliação da inteligibilidade de fala no ruído sem o DPA, foi detectado efeito de interação entre uso do DPA e relação S/R (p=0,010) sobre a média das porcentagens de acertos. Na avaliação com listas de sentenças, a porcentagem de acertos com DPA foram superiores a 98% no silêncio; contudo, no ruído houve piora, com efeito de interação entre intensidade de fala e relação S/R (p=0,010) e entre grupo e relação S/R (p=0,039). Na comparação do uso/não uso do DPA, houve efeito de interação entre uso do DPA e as relações S/R (p=0,009) sobre a média das porcentagens de acertos. Conclusões: Para ambos os grupos, houve piora da inteligibilidade de fala com o aumento da intensidade do ruído; contudo, a dificuldade foi maior para o G2. Na comparação das situações com/sem o uso do DPA, o uso dificultou a inteligibilidade de fala, mas não houve diferença significante entre as situações. Por fim, ressalta-se a importância de realizar mais estudos dos efeitos do DPA na comunicação, além de inserir nas avaliações ocupacionais testes que avaliam a fala no ruído, para determinar as dificuldades que podem surgir no ambiente ocupacional, e assim desenvolver medidas que beneficiem os trabalhadores que necessitam se comunicar durante as atividades laborais / Introduction: Noise is one of the main agents of environmental pollution, and at high intensities, it may provoke noise-induced hearing loss (NIHL). NIHL is the second most frequent type of sensorineural hearing loss and it is considered one of the main occupational diseases. In order to avoid the effects of the exposition to occupational noise, legislation determines the monitoring and development of actions to reduce the effects of such exposure and one of the most applied measure is the mandatory use of hearing protection devices (HPD). However, workers often report difficulties to communicate when using the HPD, what may induce them to use it improperly. Previous studies showed divergences between the effects of HPD on speech intelligibility; besides, few studies compared participants with hearing loss to those with normal hearing. Purpose: To assess speech intelligibility of workers exposed to noise during the use of HPD. Methods: This is a cross-sectional study, approved by the Institution\'s Ethics Committee (nº 130/14) and counted on a sample of 36 participants, all males and exposed to noise. They were distributed into a normal hearing group (G1), with 20 participants and hearing loss group (G2), with 16 participants. All participants were submitted to an assessment of speech intelligibility in free field, using monosyllable and sentence lists, when using the HPD in silence and noise situation, and also without the use of HPD in noise. Results: In the assessment of speech intelligibility with HPD using the monosyllables, both groups presented percentages of correct answers above 95%. In the presence of noise with HPD, there was no interaction effect involving group (p>=0.106) or group effect (p=0.182), but there was found an interaction effect between speech intensity and signal-to-noise ratio (SNR) (p=0.006). In the assessment of speech intelligibility in noise without HPD, an interaction effect between HPD use and SNR (p=0.010) was detected over the mean percentage of correct answers. In the evaluation with lists of sentences, the percentage of correct answers with HPD were superior to 98% in the silence; however, in noise, there was a decrease on the interaction effect between speech intensity and SNR (p = 0.010) and between group and SNR (p = 0.039). In the comparison with/without use of HPD, there was found an interaction effect between hearing protection use and SNR (p = 0.009) on the mean percentage of correct answers. Conclusions: For both groups, it was noticed that speech intelligibility decrease with the increasing of noise intensity; nevertheless, the difficulty was greater for the group with hearing loss. In the comparison of situations with and without the use of HPD, its use made speech intelligibility more challenging, but no significant difference between the situations was found. Finally, it is important to highlight the importance of further studies regarding the effects of HPD on communication and, besides, inserting speech-in-noise tests in occupational examination in order to determine the difficulties that may arise in the occupational environment and thus, develop measures that benefits the workers who need communicate during their labor activities

Objetivos: 1) Estimar a prevalência do incômodo causado pelo ruído em trabalhadores de estabelecimentos comerciais no município de São Paulo. 2) Identificar o conhecimento e a opinião dos trabalhadores de estabelecimentos comerciais em relação ao ruído urbano 3) Identificar fatores sócio-demográficos associados ao incômodo, ao conhecimento e a opinião em relação ao ruído urbano. Métodos: Estudo transversal com 400 trabalhadores de estabelecimentos comerciais situados na zona central do município de São Paulo. O instrumento utilizado foi um questionário que contemplava questões sobre dados sócio-ambientais, ruído e aspectos relacionados aos incômodos por ele causados. As entrevistas foram realizadas no próprio estabelecimento onde o trabalhador atuava, em horário comercial. Mediu-se também o nível de pressão sonora no posto de trabalho, em um estabelecimento de cada rua visitada. Resultados: Dos 400 participantes, 59% eram do sexo feminino. A idade dos indivíduos variou entre 18 e 89 anos, com a mediana de 31 anos. 60% tinham nível escolar médio completo ou incompleto, 46% eram do setor de moda e 44% exerciam a função de balconista. Espontaneamente o ruído aparece em quarto colocado em incômodos no município e em primeiro em incômodo no local de trabalho e na residência. Do total, 65,75% achavam o local de trabalho ruidoso e 62,5% se mostraram incomodados com ruído neste local. O ruído interferia na atividade laboral de 43% dos trabalhadores sendo que a principal falar ao telefone (54%). Os principais problemas causados ou agravados pelo ruído, na opinião dos trabalhadores foram: perda auditiva, (72%), estresse (29%), irritabilidade (9%), dor de cabeça (7%), nervosismo (3%) e alterações do sono (1%). A maioria dos entrevistados referiu ter boa audição (96%). O sexo masculino e o maior nível de escolaridade se mostraram associados ao fato do trabalhador referir que o local de trabalho era ruidoso. Conclusões: A prevalência de trabalhadores que trabalhavam em estabelecimentos comerciais no município de São Paulo que referiram incômodo relacionado ao ruído no local de trabalho foi estimada em 62,5%. Referiram que o local de trabalho era ruidoso 65,75% trabalhadores e, o ruído do tráfego no local de trabalho incomodou 62% trabalhadores. Com os resultados deste estudo pode-se inferir que os trabalhadores conheciam tanto o risco físico do ruído, quanto o incômodo que ele pode causar. Os trabalhadores relataram que o ruído poderia causar ou agravar alguns problemas de saúde, principalmente a perda auditiva, estresse e irritabilidade / Objectives: 1) To evaluate the annoyance caused by noise among workers of commercial establishments of the city o Sao Paulo. 2) To find out the knowledge and opinion of these workers about the urban noise. 3) To identify socio-demographic factors associated to the annoyance, the knowledge and the opinion of the workers of commercial establishments in the city of Sao Paulo about the urban noise. Methods: This is a cross sectional study with 400 workers of commercial establishments located at the central area of the city of Sao Paulo. It was used a questionnaire that included questions about socio-environmental, noise and aspects related to the annoyances caused by them. The interviews were carried on at the workers workplace, during working hours. It was also measured the noise level at the workstation in one establishment of every street visited. Results: Of the 400 participants, 59% were female. The age ranged from 18 and 89 years old, with a median of 31 years. 60% of them had complete or incomplete high school educational level, 46% worked with clothes, and 44% were clerks. Noise appears spontaneously in fourth place among the annoyances at the workplace and at home. Of the participants 65.75% considered the workplace noisy, and 62.5% declared the felt annoyed by the noise at this place. Noise interfered with the professional activities of 43% of the workers, being talking to the phone the main activity disrupted (54%). Main problems caused or worsened by noise, for the workers, were: hearing loss (72%), stress (29%), irritability (9%), headache (7%), nervousness (3%), and sleep disturbances (1%). Most of the interviewed workers consider themselves as having a good hearing (96%). Male gender and higher schooling level were associated to the fact the worker mentions the workplace is noisy. Conclusions: The prevalence of people working at commercial establishments in the city of Sao Paulo who mentioned annoyance related to noise at the workplace was estimated to be 62.5%. 65.75% of the workers mentioned that the workplace was noisy, and the traffic noise was disturbing for 62% of the workers. From the results of this study it can inferred that the workers knew the physical risks associated to noise and the annoyances it can cause. The workers mentioned that noise could cause or worsen some health problems, especially hearing loss, stress and irritability