Noise-induced hearing loss: a 10-year analysis of notifications according to the Brazilian Classification of Occupations.

Introduction: Noise-induced hearing loss has a high incidence among Brazilian workers, causing socioeconomic and cognitive impairments. Objectives: To describe noise-induced hearing loss according to professional occupation between 2012 and 2021. Methods: This was a cross-sectional and descriptive study of Brazilian workers affected by noise-induced hearing loss. Data were collected from noise-induced hearing loss notifications filed with the Sistema de Informação de Agravos de Notificação in Brazil. The absolute and relative frequencies of sociodemographic variables and occupational characteristics were assessed. Results: A total of 7,413 cases of noise-induced hearing loss were notified in Brazil. Workers in industrial production were the most affected (56.4%). There was a higher prevalence in White (45.4%), male (87.3%) participants aged between 50 and 59 years (42.5%) from the Southeast region (43%). In this study, 3.5% of participants were temporarily removed from their position, 42.6% reported using personal protective equipment, and 65.7% did not use collective protective equipment. The most prevalent type of noise was continuous noise (33%). Conclusions: Noise-induced hearing loss is prevalent among Brazilian workers and varies according to each occupational group. Cases of noise-induced hearing loss are underreported in Brazil.

Introdução: A perda auditiva induzida por ruído possui alta incidência entre os trabalhadores brasileiros, acarretando prejuízos socioeconômicos e cognitivos. Objetivos: Descrever a perda auditiva induzida por ruído no Brasil segundo a ocupação entre os anos de 2012 e 2021. Métodos: Tratou-se de um estudo transversal e descritivo, cuja população-alvo foi trabalhadores brasileiros afetados pela perda auditiva induzida por ruído. Os dados foram coletados a partir das fichas de notificação de perda auditiva induzida por ruído, oriundas do Sistema de Informação de Agravos de Notificação no período de 2012 a 2021. Foram analisadas as frequências absoluta e relativa de variáveis sociodemográficas e de características do trabalho. Resultados: Foram notificados 7.413 casos de perda auditiva induzida por ruído no país, sendo o grupo de trabalhadores da produção de bens e serviços industriais o mais afetado (56,4%). Houve maior proporção de casos em indivíduos do sexo masculino (87,3%), com cor de pele branca (45,4%), na faixa etária de 50 a 59 anos (42,5%) e da região Sudeste (43%). Entre os trabalhadores, 3,5% foram afastados temporariamente de suas ocupações, 42,6% faziam uso de medidas de proteção individual e 65,7% não utilizavam proteção coletiva. O ruído contínuo foi predominante (33%). Conclusões: A perda auditiva induzida por ruído é prevalente entre os trabalhadores brasileiros e varia conforme o grupo ocupacional. Os casos de perda auditiva induzida por ruído são subnotificados no Brasil.

Auditory changes in awake guinea pigs exposed to overcompressed music.

Exposure to loud sound during leisure time is identified as a significant risk factor for hearing by health authorities worldwide. The current standard that defines unsafe exposure rests on the equal-energy hypothesis, according to which the maximum recommended exposure is a tradeoff between level and daily exposure duration, a satisfactory recipe except for strongly non-Gaussian intense sounds such as gunshots. Nowadays, sound broadcast by music and videoconference streaming services makes extensive use of numerical dynamic range compression. By filling in millisecond-long valleys in the signal to prevent competing noise from masking, it pulls sound-level statistics away from a Gaussian distribution, the framework where the equal-energy hypothesis emerged. Auditory effects of a single 4 hour exposure to the same music were compared in two samples of guinea pigs exposed either to its original or overcompressed version played at the same average level of 102 dBA allowed by French regulations. Apart from a temporary shift of otoacoustic emissions at the lowest two frequencies 2 and 3 kHz, music exposure had no detectable cochlear effect, as monitored at 1, 2 and 7 days post-exposure. Conversely, middle-ear muscle strength behaved differentially as the group exposed to original music had fully recovered one day after exposure whereas the group exposed to overcompressed music remained stuck to about 50% of baseline even after 7 days. Subsamples were then re-exposed to the same music as the first time and sacrificed for density measurements of inner-hair-cell synapses. No difference in synaptic density was found compared to unexposed controls with either type of music. The present results show that the same music piece, harmless when played in its original version, induces a protracted deficit of one auditory neural pathway when overcompressed at the same level. The induced disorder does not seem to involve inner-hair cell synapses.

Development of a clinical investigation protocol for occupational auditory health.

Introduction: Considering that noise is present in different work environments, occupational health regulations have been created that advocate for the care of employees' auditory system in these environments. Occupational hearing assessment should be performed by audiologists through audiological examinations, otoscopy, as well as an interview to assess possible risk factors for the development of hearing loss. However, up to the present moment, a standardized set of updated questions for this interview has not been defined. Objectives: To develop a clinical investigation instrument for occupational auditory health that provides support for clinical decision-making and differential diagnosis. Methods: The study was conducted using Design Thinking as a methodological approach in its stages of inspiration (problem identification), ideation (theoretical foundation and protocol design), and prototyping (protocol construction). Experience report: This study was conducted with the objective of providing support for clinical decision-making and differential diagnosis of the auditory aspects of the assisted population. The Protocolo de Investigação Clínica da Saúde Auditiva Ocupacional was developed, consisting of six main sections that address medical history, lifestyle habits, exposure to non-occupational noise, work history, extra-auditory symptoms, and auditory and vestibular signs and symptoms, aimed at investigating workers' auditory health and related aspects. Conclusions: The developed instrument can be used for data collection and assist audiologists in the occupational health teams in diagnosis and decision-making processes.

Introdução: Considerando que o ruído está presente em diferentes ambientes laborais, foram criadas normas regulamentadoras de saúde ocupacional que preconizam o cuidado com o sistema auditivo dos colaboradores destes ambientes. A avaliação auditiva ocupacional deve ser realizada pelo fonoaudiólogo através dos exames de audiometria e meatoscopia, além de uma entrevista para avaliar possíveis fatores de risco para o desenvolvimento de perdas auditivas. Entretanto, até o presente momento não foi definido um padrão de perguntas atualizado para esta entrevista. Objetivos: Desenvolver um instrumento de investigação clínica da saúde auditiva ocupacional que ofereça suporte para tomadas de decisões clínicas e diagnóstico diferencial. Métodos: O estudo foi desenvolvido utilizando o design thinking como abordagem metodológica em suas etapas de inspiração (observada a problemática), ideação (fundamentação e delineamento teórico do protocolo) e prototipação (construção do protocolo). Relato da experiência: Este estudo foi realizado objetivando oferecer suporte para tomadas de decisões clínicas e diagnóstico diferencial dos aspectos auditivos da população assistida. Foi desenvolvido o Protocolo de Investigação Clínica da Saúde Auditiva Ocupacional, composto de seis seções principais que abordam o histórico clínico, hábitos de vida, exposição a ruído extraocupacional, histórico laboral, sintomas extra-auditivos e sinais e sintomas auditivos e vestibulares, que visam investigar a saúde auditiva do trabalhador e aspectos relacionados a ela. Conclusões: O instrumento desenvolvido poderá servir para a coleta de dados e auxílio para diagnóstico e tomada de decisões dos fonoaudiólogos das equipes de saúde ocupacional.

Time Trend of Occupational Noise-induced Hearing Loss in a Metallurgical Plant With a Hearing Conservation Program.

Background: This study aimed to analyze the trend of occupational noise-induced hearing loss (ONIHL) in Brazilian workers at a metallurgical plant with a hearing conservation program (HCP), which has been addressed in a previous study. Methods: All 152 workers in this time series (20032018) participated in the HCP and used personal protective equipment. All annual audiometry records in the company's software were collected from the electronic database. The trend of ONIHL was analyzed with the joinpoint regression model. The hearing thresholds of ONIHL cases at the end of the series were compared with those found in a national reference study. Results: The binaural mean hearing thresholds at 3, 4, and 6 kHz at the end of the series were higher for ages ≥50 years, exposures ≥85 dB (A), time since admission >20 years, and maintenance workers. Significance was found only in the group divided by age. There was an increasing time trend of ONIHL, though with a low percentage variation for the period (AAPC = 3.5%; p = 0.01). Hearing thresholds in this study differed from the reference one. Conclusion: Despite the unmet expectation of a stationary trend in the study period, the time pace of ONIHL evolution did not follow what was expected for a population exposed to noise. These findings signal to the scientific community and public authorities that good ONIHL control is possible when HCP is well implemented.

Effectiveness of educational programs in hearing health: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the effectiveness of hearing health education programs aimed at preventing noise-induced hearing loss (NIHL), of recreational and occupational origin, by means of a systematic review and meta-analysis. DESIGN: The search strategy was carried out in on five electronic databases, as well as referrals from experts. The risk of bias was judged, and the random effects meta-analysis was performed. The certainty of the evidence was assessed. STUDY SAMPLE: Effectiveness studies that used educational intervention in hearing health and prevention of NIHL were included. RESULTS: 42 studies were included. The Dangerous Decibels program was the only one that could be quantitatively analysed and showed improvement in the post-intervention period of up to one week [SMD = 0.60; CI95% = 0.38-0.82; I2 = 92.5%) and after eight weeks [SMD = 0.45; CI95% = 0.26-0.63; I2 = 81.6%) compared to the baseline. The certainty of evidence was judged as very low. CONCLUSIONS: The Dangerous Decibels program is effective after eight weeks of intervention. The other programs cannot be quantified. They still present uncertainty about their effectiveness. The level of certainty is still low for this assessment.

Enfrentamento da subnotificação da perda auditiva induzida por ruído relacionada ao trabalho: a experiência de uma oficina educativa em planejamento e programação local em saúde do trabalhador / Addressing underreported occupational noise-induced hearing loss: the experience of an educational workshop on local occupational health planning and program

Resumo Introdução: a subnotificação da Perda Auditiva Induzida por Ruído (Pair) relacionada ao trabalho é um problema que contribui para a invisibilidade e falta de prioridade deste agravo nos programas de Saúde do Trabalhador (ST). Logo, ações de educação permanente voltadas ao planejamento estratégico-situacional podem contribuir para o enfrentamento desta realidade. Objetivo: apresentar e discutir a experiência de uma intervenção educativa com técnicos da ST de uma macrorregião de saúde do estado da Bahia, Brasil, sobre o uso do Planejamento e Programação Local em Saúde (PPLS) como ferramenta para ampliação da notificação da Pair relacionada ao trabalho Métodos: a intervenção consistiu em uma oficina estruturada em cinco etapas, as quais proporcionaram discussão sobre a Pair, conhecimento do PPLS, prática do PPLS, socialização dos resultados e avaliação do evento. Resultados: a prática do PPLS, a partir de um problema real, viabilizou o delineamento de ações concretas de enfrentamento da subnotificação da Pair a serem implementadas nos Centros de Referência em Saúde do Trabalhador (Cerest) e no estado como um todo. Conclusão: a experiência mostrou-se bem-sucedida ao fomentar a tomada de consciência e mobilização dos técnicos para enfrentamento da subnotificação da Pair, ao tempo que propiciou qualificação em PPLS dos participantes.

Abstract Introduction: underreported occupational noise-induced hearing loss (ONIHL) is an issue that increases the invisibility and lack of priority of this condition in occupational health (OH) programs. Hence, permanent education actions focused on strategic-situational planning may help address the situation. Objective: to present and discuss the experience of an educational intervention in OH technicians of a larger health region in the state of Bahia, Brazil, approaching the use of the Local Health Planning and Program (PPLS, in Portuguese) as a toll to increase reports of ONIHL. Methods: the intervention had a workshop structured into five stages, which approached ONIHL discussions, PPLS knowledge, PPLS practice, result socialization, and event evaluation. Results: real-problem PPLS practice made it possible to outline concrete actions to address underreported ONIHL, which can be implemented in Occupational Health Reference Centers (Cerest) and other settings statewide. Conclusion: the experience proved to be positive, raising technicians' awareness of underreported ONIHL and mobilizing them to address the underreporting of ONIHL, while also effectively training participants to use PPLS.

Are hearing protection devices used in the workplace really efficient? A systematic review.

BACKGROUND: The most common current hearing protection devices (HPDs) on the market include earplugs and earmuffs. A variety of materials can be used to manufacture these devices, and each offers a level of noise attenuation that is informed by the manufacturer although it does not always correspond to the attenuation observed in real-world use. OBJECTIVE: To evaluate the noise attenuation of HPDs available to workers exposed to noise. METHODS: The most relevant studies originally published in English, Portuguese, or Spanish that investigated the noise attenuation effectiveness of HPDs used by workers exposed to noise were analyzed. The following electronic databases were searched by 2 independent reviewers for studies published from 1999 to 2019: MEDLINE (PubMed), Scopus, Web of Science, EMBASE, Cochrane Library (OVID), ProQuest, and BVS-Bireme. Different combinations of the following search terms (MeSH terms) were used for all databases: "Hearing Loss, Noise-Induced", "Ear Protective Devices" (Efficacy OR Effectiveness)", "Noise, Occupational". RESULTS: The search strategy yielded a total of 326 potentially relevant studies. After the removal of duplicates, 156 remained for the screening of titles and abstracts. After reviewing titles and abstracts, 46 studies were selected for full-text reading. Of these, six were included in this systematic review. CONCLUSION: Hearing protection devices reduced the noise exposure and were effective in all included studies in different countries, types of activity, and sound pressure exposure.

Tradução, adaptação e validação transcultural para o português brasileiro do questionário de Avaliação da Proteção Auditiva (APA) / Translation, adaptation, and cross-cultural validation into Brazilian portuguese of the hearing protection assessment questionnaire (HPA)

RESUMO Objetivo O objetivo do presente estudo foi traduzir, adaptar e validar transculturalmente a versão para língua portuguesa brasileira do questionário Hearing Protection Assessment Questionnaire (HPA). Método O instrumento original, desenvolvido na língua inglesa, buscou avaliar as barreiras e suportes relacionados ao uso dos dispositivos de proteção auditiva (DPA), assim como o conhecimento, hábitos e atitudes dos trabalhadores frente ao ruído ocupacional. A tradução, adaptação e validação transcultural do questionário foi composta de cinco etapas: Tradução do questionário do inglês para o português; 2) Processo inverso de tradução do português para o inglês; 3) Análise do instrumento por três especialistas na área; 4) Pré-teste do questionário com 10 trabalhadores; 5) Aplicação do instrumento em 509 trabalhadores de uma indústria frigorífica após o exame admissional. Resultados os resultados indicam a validade de construção e conteúdo da versão em Português Brasileiro para o seu uso com uma população trabalhadora e a consistência interna do mesmo. Conclusão Este estudo resultou na tradução, na adaptação cultural e validação do questionário Hearing Protection Assessment Questionnaire (HPA) com a finalidade de ser usado para avaliar o uso de proteção auditiva individual em âmbito ocupacional, denominado Questionário de Avaliação da Proteção Auditiva (APA).

ABSTRACT Purpose The aim of the present study is to translate, adapt, and cross-culturally validate the Brazilian Portuguese version of the questionnaire Hearing Protection Assessment Questionnaire (HPA). Methods The original instrument, developed in English, seeks to assess barriers and supports related to the use of hearing protection devices (HPD), as well as workers' knowledge, habits and attitudes towards occupational noise. The translation, adaptation, and cross-cultural validation of the questionnaire consisted of five steps: Translation of the questionnaire from English to Portuguese; 2) Reverse translation from Portuguese to English; 3) Analysis of the instrument by three experts in the field; 4) Pre-test of the questionnaire with ten workers; 5) Application of the instrument to 509 workers in a meatpacking industry after the pre-employment medical exam. Results The results indicate the construction and content validity of the Brazilian Portuguese version for use with a working population and its internal consistency. Conclusion This study resulted in the translation, cultural adaptation, and validation of the Hearing Protection Assessment Questionnaire (HPA), in order to be used to assess the use of individual hearing protection in the occupational field, called Hearing Protection Assessment Questionnaire (HPA).

Tradução e adaptação transcultural do Noise Exposure Questionnaire (NEQ) para o português brasileiro / Translation and cross-cultural adaptation of the Noise Exposure Questionnaire (NEQ) to Brazilian Portuguese

RESUMO Objetivo Traduzir e realizar a adaptação transcultural dos instrumentos Noise Exposure Questionnaire (NEQ) e 1-Minute Noise Screen (NEQ-S) para a versão em português brasileiro. Método O processo de tradução e adaptação transcultural seguiu procedimentos amplamente utilizados em pesquisas da área da saúde, compostos pelas seguintes etapas: tradução inicial, síntese das traduções, retrotradução, comitê de especialistas, pré-teste, e validação do conteúdo e aparência. Na etapa de pré-teste, participaram 60 trabalhadores, que responderam aos questionários e, posteriormente, os avaliaram quanto ao: entendimento, aparência, clareza e escrita. Para a verificação da confiabilidade, foi utilizado o teste kappa de Cohen e para a análise da consistência interna foi aplicado o coeficiente alfa de Cronbach. Resultados As versões traduzidas e adaptadas dos questionários NEQ e NEQ-S mostraram-se semelhantes em relação ao significado geral e referencial. Entretanto, algumas modificações e adaptações foram realizadas, para adequação à realidade brasileira. O teste kappa indicou concordância moderada e o coeficiente alfa de Cronbach, consistência interna substancial. Conclusão A tradução e a adaptação transcultural foram realizadas de acordo com a metodologia preconizada na literatura nacional e internacional, incluindo-se as equivalências necessárias para a manutenção da validade de face e conteúdo com o instrumento original. A disponibilização dos questionários NEQ e NEQ-S na versão da língua portuguesa brasileira abre novos campos de pesquisa para aprofundamento da quantificação de exposição anual ao ruído.

ABSTRACT Objective To translate and cross-culturally adapt the Noise Exposure Questionnaire (NEQ) and 1-Minute Noise Screen (NEQ-S) instruments to Brazilian Portuguese. Methods Procedures widely known in health research were used in the translation and cross-cultural adaptation process, comprising the following steps: initial translation, synthesis of translations, back-translation, expert committee, pretest, and content and layout validation. Altogether, 60 workers participated in the pretest by answering the questionnaires and then evaluating them in terms of understandability, layout, clarity, and writing. Reliability was verified with Cohen's kappa test, and the internal consistency was analyzed with Cronbach's alpha coefficient. Results The translated and adapted versions of NEQ and NEQ-S were similar in terms of general and referential meanings. However, some modifications and adaptations were made to adapt them to the Brazilian reality. The kappa test indicated moderate agreement and Cronbach's alpha coefficient, substantial internal consistency. Conclusion The translation and cross-cultural adaptation were carried out according to the methodology recommended in the national and international literature, performing the necessary equivalences to maintain the face and content validity with the original instrument. The availability of NEQ and NEQ-S in Brazilian Portuguese opens new fields of research to quantify yearly noise exposure more in-depth.

The circadian timing of noise exposure influences noise-induced inflammatory responses in the mouse cochlea

Abstract Introduction: Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss. Nevertheless, the mechanisms of noise-induced hearing loss are still not fully understood. Objective: To investigate the dynamics of inflammatory responses in the mammalian cochlea following noise trauma at two different times, once during the light cycle and once during the dark. Methods: We challenged C57BL/6J mice with moderate, continuous noise trauma at either 9 a.m. or 9 p.m. Auditory function, histological changes in hair cells, and modifications in gene expression levels of inflammatory mediators were assessed at specific time points. Shifts in auditory brainstem response thresholds were measured at 1, 3, 7 and 14 days after noise exposure to measure potential noise-induced hearing loss. Cochlear basilar-membrane immunofluorescent staining was performed at 3 and 14 days after noise exposure. The mRNA levels of several inflammatory mediators were measured via quantitative real-time polymerase chain reaction before (pre) and after (0, 3, 12, 24 and 72 h) noise exposure. Results: We found that all noise-exposed mice developed a temporary threshold shift and that there were no significant differences between daytime and nighttime noise exposures in terms of inducing hearing-threshold shifts. Similarly, we did not detect significant histological changes in hair cells between these two groups. However, we discovered an interesting phenomenon in that the peak mRNA levels of IL-1β, IL-6, CCL2 and TNF-α were higher in day noise-exposed mice compared to those in night noise-exposed mice, and these mRNA levels subsided more slowly in day noise-exposed mice. Conclusion: Overall, these observations suggest that the circadian timing of noise exposure has a significant effect on noise-induced inflammatory responses in the mouse cochlea and that a greater inflammatory response might occur after daytime exposure.

Is it necessary to perform occupational audiometric testing at 6-months of employment? / É necessário fazer teste audiométrico ocupacional 6 meses após a admissão?

Abstract Introduction: Current Brazilian legislation requires that all workers exposed to noise are to be given an audiogram upon hiring, after 6 months of employment (first periodic test), and annually after the first periodic test. In other countries, the regulations of hearing conservation programs do not include the requirement for audiometric testing at 6 months of employment, but only annually. There is no evidence that the periodicity adopted by Brazilian legislation is the most appropriate. Objective: The present study aimed to evaluate the first 3 occupational audiometric tests of workers exposed to noise. Methods: Historical cohort study with cross-sectional analysis. Participants were all male metallurgy workers aged up to 40 years. The first 3 audiograms of each worker were analyzed: pre-employment audiometric test, periodic audiometric test 1, and periodic audiometric test 2. For each worker, mean frequency thresholds were calculated at 3, 4, and 6 kHz in the left and right ears for each test. Statistical analysis was performed using the nonparametric Wilcoxon test. Results: A total of 988 workers were included. There was a significant difference in auditory thresholds between the pre-employment test and the 2 subsequent periodic tests for the right and left ears. There was no significant difference between Test1 and Test2 in either ear. Conclusion: Given the lack of difference between the first 2 periodic tests, we believe that they could be merged into a single test, i.e., first periodic audiometric testing could be performed at 12 months of employment without compromising workers' health.

Resumo Introdução: A legislação brasileira atual exige que todos os trabalhadores expostos a ruído recebam um audiograma na admissão, 6 meses após a admissão (primeiro teste periódico), e anualmente após o primeiro teste periódico, mas em outros países as regulamentações dos programas de conservação auditiva não incluem a exigência de teste audiométrico após 6 meses de admissão, mas apenas anualmente. Não há evidências de que a periodicidade adotada pela legislação brasileira seja a mais adequada. Objetivo: Avaliar os três primeiros exames audiométricos ocupacionais de trabalhadores expostos ao ruído. Método: Estudo de coorte histórica com análise transversal. Os participantes eram todos trabalhadores metalúrgicos do sexo masculino com até 40 anos. Os três primeiros audiogramas de cada trabalhador foram analisados: teste audiométrico pré-admissão, teste audiométrico periódico 1 e teste audiométrico periódico 2. Para cada trabalhador, os limiares de frequência médios foram calculados em 3, 4 e 6 kHz nas orelhas esquerda e direita para cada teste. A análise estatística foi feita através do teste não paramétrico de Wilcoxon. Resultados: Foram incluídos 988 trabalhadores. Houve uma diferença significante nos limiares auditivos entre o teste pré-admissão e os 2 testes periódicos subsequentes para as orelhas direita e esquerda. Não houve diferença significante entre o teste 1 e o teste 2 em nenhuma das orelhas. Conclusão: Dada a falta de diferença entre os 2 primeiros testes periódicos, acreditamos que eles poderiam ser combinados em um único teste, ou seja, o primeiro teste audiométrico periódico poderia ser feito após 12 meses de admissão sem comprometer a saúde dos trabalhadores.

Increased Signs of Noise-Induced Hearing Loss in Dental Students: A Multilevel Approach.

Context: Despite the fact that the new generations of rotary tools emit less noise, some recent studies suggest that dental students are still at risk of hearing impairment. Aims: The aim of the study was to determine a possible association between noise exposure from dental equipment and early signs of noise-induced hearing loss (NIHL) in dental students. Settings and Design: A cross-sectional study was carried out with dental and non-dental students from two universities in Chile. Methods and Material: A group of 102 dental students routinely exposed to noise emitted from dental equipment was selected as the study group. A group of 251 non-dental students was selected as the control group. Pure-tone audiometry was carried out on all participants ensuring that they were not exposed to noise for at least 24 hours prior to testing. The presence of a notch was determined for each participant. Statistical analysis used: Simultaneous-quantile regressions were used to compare percentiles of the hearing threshold between both groups. Then, the notch prevalence ratio adjusted by gender and age was estimated for each group of participants. Finally, the prevalence of an audiometric notch was compared between both groups using logistic regression models and generalized linear methods. Both fixed effect and multilevel hierarchy models were constructed. Results: Significant differences between groups for the 75th percentile of hearing threshold distributions at 4 and 6 kHz in the left ear and at 6 kHz in the right ear were found. In addition, study group participants exhibited a significantly higher prevalence of a notch at 4 kHz in the left ear than control group participants. Conclusions: Exposure to noise derived from learning activities as a dental student is associated with early signs of NIHL. Such signs include poorer hearing thresholds than those of non-dental students at 4 and 6 kHz as well as the presence of a notch at high frequencies.

Effects of Noise and Chemical Exposure on Peripheral and Central Auditory Pathways in Normal-hearing Workers.

Objectives: To assess the effects of noise and chemical exposure on peripheral and central auditory pathways in normal-hearing workers exposed to chemicals or high noise levels and compare the groups with each other and with workers not exposed to either of these agents. Methods: A total of 54 normal-hearing workers were divided into three groups (chemical, noise, control) and submitted to the following assessments: conventional and extended high-frequency pure-tone audiometry; transient and distortion-product otoacoustic emissions, the inhibitory effect of the efferent auditory pathway; and Staggered Spondaic Word (SSW) and Pitch Pattern Sequence (PPS) test. Results: There were no significant differences between the groups in extended high-frequency hearing thresholds. Significantly lower amplitudes were observed in the noise group for otoacoustic emissions. There were significantly more absences of the inhibitory effect of the efferent system in the noise group. There was no difference between the groups in the SSW test, while in PPS, the noise group performed worse than the control group. Conclusion: These findings suggest that noise exposure produced deleterious effects on the workers' peripheral and central auditory systems, despite their normal hearing thresholds. The chemical group did not have significantly different results from those of the control group. It is important that individuals exposed to noise or chemicals have their auditory pathways monitored with complementary assessments.

The effectiveness of berberine on noise-induced hearing loss: a rat model

SUMMARY OBJECTIVE: Noise-induced hearing loss is a preventable form of hearing loss that has serious social and economic impacts. This study aimed to investigate the protective effect of berberine, a potent antioxidant and anti-inflammatory agent, against Noise-induced hearing loss. METHODS: After applying distortion product otoacoustic emission, 28 female Sprague-Dawley rats were randomly divided into four groups. Group 1 was designated as acoustic trauma group, and rats in this group were exposed to white noise for 12 h at an intensity of 4 kHz 110 dB sound pressure level. Group 2 was the control group. Group 3 was designated as the berberine group, and 100 mg/kg of berberine was administered to rats in this group by intragastric lavage for five consecutive days. Group 4 was designated as the acoustic trauma+berberine group. distortion product otoacoustic emission was repeated on the 6th day of the study and cochlear tissues of rats were dissected for histopathological and immunohistochemical analyses after sacrificing rats. RESULTS: The distortion product otoacoustic emission results showed a significant decrease in signal-noise ratio values at higher frequencies in rats of the trauma group compared to those in other groups. Acoustic trauma caused severe histopathological impairment at cochlear structures together with severe 8-hydroxy-2-deoxyguanosine expression. Rats in the acoustic trauma+berberine group showed mild histopathological changes with mild 8-hydroxy-2-deoxyguanosine expression and better signal-noise ratio values. CONCLUSION: The histopathological and audiological findings of this experimental study showed that berberine provides protection in Noise-induced hearing loss and may have the potential for use in acoustic trauma-related hearing losses.

Evaluation of the Dangerous Decibels Brazil Program in Workers Exposed to Noise.

Introduction: Noise-induced hearing loss can be avoided by taking preventive measures. Objective: To assess the effectiveness of the Brazilian version of the Dangerous Decibels® program for noise-exposed workers, using the ecological model as an educational intervention plan. Method: Non-randomized interventional study with a quantitative, experimental trial design, conducted at a meatpacking company. The participants were divided into two groups-the first one (n = 132, divided into 6 subgroups) received the Dangerous Decibels® Brazil educational intervention (DDBEI) adapted to workers while the second group (n = 138, divided into 5 subgroups) received a conventional educational intervention (CEI). The interventions lasted 50 min. The Hearing Protection Assessment Questionnaire (HPA-5) was administered before and after the interventions. The five dimensions (attitude, behavior, knowledge, supports, and barriers) were compared using the Student's t-test for paired data (<0.05). Results: After both the DDBEI and CEI training, workers improved significantly in barriers, supports, knowledge, attitudes, and behavior around noise. By chance, the CEI group scored lower in all measures than the DDBEI group before training, and though both groups improved, the difference was maintained after training. Conclusion: The Brazilian version of the Dangerous Decibels® program for noise-exposed workers was effective, influencing positively the factors at different levels of the ecological model. Though the DDBEI was no more effective than the CEI, the CEI participants began at much lower levels, so the effectiveness of the DDBEI may have been underestimated.

Impacto das ações do centro de referência em saúde do trabalhador nos dados de notificação compulsória de pair no Distrito Federal: um estudo qualitativo / The impact of the measures by the reference centers in worker's health on the compulsory notification nihl data in the Brazilian Federal District: a qualitative study / Impacto de las acciones del centro de referencia de salud del trabajador en los datos de notificación obligatoria de pair en el Distrito Federal: un estudio cualitativo

Introdução: A Perda Auditiva Induzida por Ruído (PAIR) é um agravo que acomete os trabalhadores expostos a ruídos e está entre os agravos que devem ser notificados no Sistema de Informação de Agravos de Notificação (SINAN). Objetivo: Analisar o impacto das ações desenvolvidas pelo Centro de Referência em Saúde do Trabalhador (CEREST-DF) em relação às notificações de PAIR no Distrito Federal. Métodos: Foi realizado um estudo longitudinal, retrospectivo com base na análise de dados secundários de notificações de PAIR do SINAN-DF, desde sua implementação; foram levantados relatórios dos CEREST-DF sobre as ações desenvolvidas; e análise de documentos dos CEREST procurando pelas ações que foram realizadas sobre PAIR e o impacto que causaram. Resultados: utilizando ações, como: projetos, palestras, busca-ativa, entre outros, o CEREST realiza a prática da educação em saúde, e, com o conhecimento fornecido ao público-alvo, é perceptível o aumento de notificações nos mesmos períodos de realização das ações com os trabalhadores e empregadores. Além disso, a contratação de fonoaudiólogo para a equipe do CEREST também eleva estes números, pois é o profissional envolvido na saúde auditiva de modo geral. Conclusão: A partir deste estudo foi possível observar que as ações do CEREST se refletem no número de notificações de PAIR no SINAN, reduzindo a subnotificação.

Introduction: Noise-Induced Hearing Loss (NIHL) is a hearing impairment that affects workers exposed to loud noises and is one of the conditions that must be reported to the Brazilian Disease Reporting Information System (SINAN). Objective: To analyze the impact of the measures developed by the Reference Centers in Workers' Health (CEREST-DF) in relation to NIHL notifications in the Brazilian Federal District. Methods: A longitudinal, retrospective study was carried out based on the analysis of secondary data of NIHL notifications from SINAN-DF. Since its implementation. CEREST-DF reports were collected on the measures developed and analysis of CEREST documents looking for measures that were carried out with NIHL and the effect they caused. Results: Utilizing educational measures such as projects, lectures, active search, among others CEREST carries out health education, and to target audiences, there was a noticeable increase in notifications in the same periods of these measures being carried out with employees and employers. In addition, a speech therapist was hired by the CEREST team what also helped to increase these numbers, since speech therapists are professionals involved in the health of hearing. Conclusion: This study made it possible to see that the measures carried out by CEREST are reflected in the number of NIHL notifications in SINAN which helped to reduce under-reporting.

Introducción: La Pérdida Auditiva Inducida por Ruido (PAIR) es un problema que afecta a los trabajadores expuestos al ruido y se encuentra entre los problemas que deben ser reportados en el Sistema de Informação de Agravos de Notificação (SINAN; Sistema de Información Sanitaria Notificable).Objetivo:Analizar si las acciones desarrolladas por el Centro de Referência em Saúde do Trabalhador do Distrito Federal (CEREST-DF; Centro de Referencia de Salud Ocupacional) reflejan en el número de notificaciones de PAIR en el DF. Métodos:Se realizó un estudio longitudinal, retrospectivo, basado en el análisis de datos secundarios de notificaciones de PAIR del SINAN-DF, desde su implementación; Se recopilaron informes de CEREST-DF sobre las acciones desarrolladas; y análisis de documentos de CEREST buscando las acciones que se tomaron sobre PAIR y el impacto que causaron. Resultados: Utilizando acciones como: proyectos, conferencias, búsqueda activa, entre otras, CEREST realiza la práctica de educación en salud, y, con el conocimiento proporcionado al público objetivo, se nota el incremento de notificaciones en los mismos períodos de acciones con trabajadores y empleadores. Además, la contratación de un (a) logopeda para el equipo de CEREST también eleva estos números, ya que éste (ésta) es el (la) profesional relacionado (a) con la salud auditiva en general. Conclusión: A partir de este estudio se pudo observar que las acciones de CEREST se reflejan en el número de notificaciones de PAIR en SINAN, reduciendo el subregistro.

The circadian timing of noise exposure influences noise-induced inflammatory responses in the mouse cochlea.

INTRODUCTION: Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss. Nevertheless, the mechanisms of noise-induced hearing loss are still not fully understood. OBJECTIVE: To investigate the dynamics of inflammatory responses in the mammalian cochlea following noise trauma at two different times, once during the light cycle and once during the dark. METHODS: We challenged C57BL/6J mice with moderate, continuous noise trauma at either 9 a.m. or 9 p.m. Auditory function, histological changes in hair cells, and modifications in gene expression levels of inflammatory mediators were assessed at specific time points. Shifts in auditory brainstem response thresholds were measured at 1, 3, 7 and 14 days after noise exposure to measure potential noise-induced hearing loss. Cochlear basilar-membrane immunofluorescent staining was performed at 3 and 14 days after noise exposure. The mRNA levels of several inflammatory mediators were measured via quantitative real-time polymerase chain reaction before (pre) and after (0, 3, 12, 24 and 72 h) noise exposure. RESULTS: We found that all noise-exposed mice developed a temporary threshold shift and that there were no significant differences between daytime and nighttime noise exposures in terms of inducing hearing-threshold shifts. Similarly, we did not detect significant histological changes in hair cells between these two groups. However, we discovered an interesting phenomenon in that the peak mRNA levels of IL-1ß, IL-6, CCL2 and TNF-α were higher in day noise-exposed mice compared to those in night noise-exposed mice, and these mRNA levels subsided more slowly in day noise-exposed mice. CONCLUSION: Overall, these observations suggest that the circadian timing of noise exposure has a significant effect on noise-induced inflammatory responses in the mouse cochlea and that a greater inflammatory response might occur after daytime exposure.

Is it necessary to perform occupational audiometric testing at 6-months of employment?

INTRODUCTION: Current Brazilian legislation requires that all workers exposed to noise are to be given an audiogram upon hiring, after 6 months of employment (first periodic test), and annually after the first periodic test. In other countries, the regulations of hearing conservation programs do not include the requirement for audiometric testing at 6 months of employment, but only annually. There is no evidence that the periodicity adopted by Brazilian legislation is the most appropriate. OBJECTIVE: The present study aimed to evaluate the first 3 occupational audiometric tests of workers exposed to noise. METHODS: Historical cohort study with cross-sectional analysis. Participants were all male metallurgy workers aged up to 40 years. The first 3 audiograms of each worker were analyzed: pre-employment audiometric test, periodic audiometric test 1, and periodic audiometric test 2. For each worker, mean frequency thresholds were calculated at 3, 4, and 6 kHz in the left and right ears for each test. Statistical analysis was performed using the nonparametric Wilcoxon test. RESULTS: A total of 988 workers were included. There was a significant difference in auditory thresholds between the pre-employment test and the 2 subsequent periodic tests for the right and left ears. There was no significant difference between Test1 and Test2 in either ear. CONCLUSION: Given the lack of difference between the first 2 periodic tests, we believe that they could be merged into a single test, i.e., first periodic audiometric testing could be performed at 12 months of employment without compromising workers' health.

Impact of a hearing conservation programs on occupational noise-induced hearing loss

ABSTRACT Purpose: to analyze the impact of a Hearing Conservation Program on occupational noise-induced hearing loss in a metallurgical plant. Methods: a longitudinal case study (2003-2018) was carried out and a Hearing Conservation Program assessed with interviews and document verification. The assessment also included 2,350 audiometric examinations and occupational noise exposure of 152 Hearing Conservation Program - participating employees, collecting the data from the company's database. Results: high compliance indices regarding occupational noise -induced hearing loss - prevention Hearing Conservation Program practices were found between 2003 and 2018. The comparison between 2018 and 2003 showed a reduced number of workers exposed to noise at 85 dB(A) or above. The final prevalence of audiometric changes suggestive of occupational noise-induced hearing loss that remained in degree I differed from the initial one in the period. The high Hearing Conservation Program percentages and low occupational noise-induced hearing loss indicators point to an inverse relationship between them. Conclusion: the results suggest a positive impact of a Hearing Conservation Program on occupational noise-induced hearing loss in this metallurgical plant, in the period studied.

Síntomas de hipoacusia y exposición al ruido recreativo en jóvenes universitarios, Barranquilla, Colombia / Hearing loss symptoms and leisure noise exposure in university students in Barranquilla, Colombia

RESUMEN Objetivo Investigar la participación de estudiantes universitarios en actividades de ocio productoras de ruido y la relación entre los niveles de exposición semanal al ruido recreativo y síntomas de hipoacusia auto reportados, en la ciudad de Barranquilla, Colombia. Método Se realizó un estudio transversal mediante encuesta virtual, basada en el Cuestionario de Exposición al Ruido, más 11 preguntas de síntomas auditivos, a una muestra aleatoria de 730 sujetos. El nivel de exposición semanal al ruido recreativo se estimó a partir del tiempo dedicado al total de actividades recreativas reportadas por los participantes y su evaluación subjetiva de la intensidad de ruido producida por cada actividad, transformada en niveles de ruido continuo equivalente. La asociación entre la exposición al ruido recreativo y la presencia de síntomas de hipoacusia se analizó mediante la prueba de Chi-cuadrado. Resultados El 93% de los participantes manifestó al menos un síntoma de hipoacusia y la mitad reportó cuatro o más. El síntoma más frecuente de hipoacusia asociada al ruido fue el tinnitus (72%). El 55% tenía una exposición semanal de ruido por encima de 85 dBA y en éstos la prevalencia de síntomas de hipoacusia fue mayor (p < 0.05). Conclusión Se sugiere la presencia de deterioro auditivo en gran parte la población universitaria, asociado con altas dosis de exposición semanal al ruido recreativo. Es necesario fortalecer los programas de promoción de la salud auditiva en la academia, y desde los servicios de salud, la valoración objetiva y periódica de la audición.

ABSTRACT Purpose The aim of this study was to investigate the total weekly exposure to leisure noise among university students and to assess its association with self-reported symptoms of hypoacusis. Methods This is a cross-sectional survey. An online questionnaire based on the "Noise Exposure Questionnaire", plus 11 questions regarding hearing loss were sent to 730 randomly selected students. Participants self-reported time spent on different leisure noise activities and their subjective evaluation of the loudness of these activities, converted into equivalent noise levels, were used to estimate weekly noise exposure levels that were compared to occupational noise limits (> 85 dBA = hazardous). Inference statistics was applied to relate hearing symptoms and "likely or having some degree of hearing loss" with hazardous weekly leisure noise exposure levels. Results Ninety-three percent of the participants reported at least one hypoacusis symptom. The most frequent sound-related ear symptom was tinnitus (72%). Fifty-five percent of the individuals presented weekly exposure to noise >85 dBA. Symptoms of hearing loss were more prevalent in those exposed to weekly noise levels >85 dBA. Conclusion This study suggests that there may be hearing loss caused by exposure to high levels of leisure noise in a large part of the study population. Health promotion of hearing conservation should be emphasized at university level. Objective repeated measurement of hearing acuity should be part of integral health services for the youth population.