[Measurement and evaluation of personal attenuation rating before and after the training of the noise-exposed workers wearing foam earplugs].

Objective: To measure and compare the difference of personal attenuation rating (PAR) of the workers wearing foam earplugs before and after the training, and to evaluate the effect of ear protector wearing training on the noise protection. Methods: In February 2023, 94 workers exposed to noise in a machinery manufacturing factory were selected as subjects. The production noise in the workplace was measured and subjects were trained to wear earplugs. The PAR values of wearing 3M 1110 foam test earplugs were measured and recorded before and after the training by using the fit testing of hearing protection device. The differences between the actual PAR values with nominal values and the noise attenuation values in related standards were compared, and the protective effect of hearing protection device before and after training was evaluated. Results: The average age of the subjects was (36.76±11.48) years old, the average length of service was (16.34±11.64) years, and the average exposure time to noise was (15.67±11.64) years. The noise detection results of the subjects' posts were ranged from 80.1 to 94.3 dB (A). The results of subjects wore 3M 1110 foam test earplugs for fit testing showed that the binaural PAR value after training was (19.3±6.4) dB (A), which was significantly higher than that before training (11.1±7.4) dB (A) (t=13.31, P<0.001). After training, 11 people (11.70%) could reach the corrected noise reduction value (NRR value), 26 people (27.66%) could reach the standard of single noise reduction value (SNR value) ×0.6, and 84 people (89.36%) could reach the standard of (NRR-7) /2. The under protection rate of hearing protectors after training (7.45%) was significantly lower than that before training (45.74%), and the difference of different protection levels before and after training was statistically significant (χ(2)=40.83, P<0.001) . Conclusion: It is suggested that enterprises should use the fit testing instead of nominal value estimation to evaluate the noise reduction effect of hearing protection device. Special training on the selection and use of hearing protection device should be strengthened, so as to ensure that workers wear them correctly and improve the protective effect of hearing protection device.

Reduction of sound levels in the intermediate care unit; a quasi-experimental time-series design study.

OBJECTIVES: This study aimed to assess the effectiveness of an architectural redesign and a multicomponent intervention bundle on noise reduction to enhance workplace safety. METHODS/DESIGN: Quasi-experimental study with a time-series and intensified intervention design conducted in an intermediate care unit. Two interventions were sequential introduced: the installation of a partition wall in the medication preparation room (architectural redesign) and the implementation of an a bundle. Effects on outcomes were evaluated comparing baseline, after architectural redesign (period-1) and after implementation of the bundle (period-2). SETTING: Intermediate care unit. MAIN OUTCOME MEASURES: A-weighted sound levels (LAeq), alarms/day/bed, annoyance ratings (numeric rating scale 0-10) and number of distractions of nurses during the medication preparation process. RESULTS: LAeq baseline vs period-1, decreased in the medication preparation area from 56.8 (±5.0) to 53.7 (±7.2) dBA (p < 0.001) and in the nursing station from 56.8 (±5.0) to 54.3 (±4.0) dBA (p < 0.001). During period-2, further noise reduction was minimal to absent. Distractions decreased from 58 % during baseline to 45 % (p < 0.001) during period-1, with no further reduction during period-2. The median [IQR] number of alarms/day/bed increased from 263 [IQR 193-320] during baseline to 394 [IQR 258-474] during period-1 (p < 0.001), then decreased to 303 [IQR 264-370] (p < 0.05) during period-2. Median annoyance ratings decreased from baseline 3.0 [IQR 2.0-6.0] to 2.0 [IQR 1.0-3.0] (p < 0.001) during period-2. CONCLUSION: An architectural redesign resulted in a significant, clinically relevant decrease in sound levels along with a notable reduction in distractions. The multicomponent bundle lowered alarms and annoyance ratings; however, its effectiveness on other outcomes seems less persuasive. IMPLICATIONS FOR CLINICAL PRACTICE: Architectural redesign seems to be effective in controlling environmental noise. Architectural redesign results in a decrease in nurses' distractions during the medication preparation process. The effect of an intervention bundle is, despite a positive effect on alarms and perceived annoyance, still insufficiently clear.

Hearing Loss in Space Flights: A Review of Noise Regulations and Previous Outcomes.

Noise is the primary cause of hearing loss during space flight. Throughout every phase of flight, particularly during launch, a significant amount of noise is generated and transferred via the vehicle's structure to the places inhabited by the crew. The results of the previous studies provide insights into space flights that may have significant effects on hearing loss. Certain precautions must be taken to ensure the habitability of the spacecraft and prevent potential hearing loss in astronauts or space flight participants.

A longitudinal study investigating the effects of noise exposure on behavioural, electrophysiological and self-report measures of hearing in musicians with normal audiometric thresholds.

Musicians are at risk of hearing loss and tinnitus due to regular exposure to high levels of noise. This level of risk may have been underestimated previously since damage to the auditory system, such as cochlear synaptopathy, may not be easily detectable using standard clinical measures. Most previous research investigating hearing loss in musicians has involved cross-sectional study designs that may capture only a snapshot of hearing health in relation to noise exposure. The aim of this study was to investigate the effects of cumulative noise exposure on behavioural, electrophysiological, and self-report indices of hearing damage in early-career musicians and non-musicians with normal hearing over a 2-year period. Participants completed an annual test battery consisting of pure tone audiometry, extended high-frequency hearing thresholds, distortion product otoacoustic emissions (DPOAEs), speech perception in noise, auditory brainstem responses, and self-report measures of tinnitus, hyperacusis, and hearing in background noise. Participants also completed the Noise Exposure Structured Interview to estimate cumulative noise exposure across the study period. Linear mixed models assessed changes over time. The longitudinal analysis comprised 64 early-career musicians (female n = 34; age range at T0 = 18-26 years) and 30 non-musicians (female n = 20; age range at T0 = 18-27 years). There were few longitudinal changes as a result of musicianship. Small improvements over time in some measures may be attributable to a practice/test-retest effect. Some measures (e.g., DPOAE indices of outer hair cell function) were associated with noise exposure at each time point, but did not show a significant change over time. A small proportion of participants reported a worsening of their tinnitus symptoms, which participants attributed to noise exposure, or not using hearing protection. Future longitudinal studies should attempt to capture the effects of noise exposure over a longer period, taken at several time points, for a precise measure of how hearing changes over time. Hearing conservation programmes for "at risk" individuals should closely monitor DPOAEs to detect early signs of noise-induced hearing loss when audiometric thresholds are clinically normal.

Evaluation of the relationship between occupational noise exposure and stress levels in a healthcare facility.

Objectives. This study aimed to assess noise levels in various units in hospitals and explore the correlation between healthcare employees' daily noise exposure level (Lex,8h) and their stress and symptoms. Methods. A healthcare facility was selected to study noise pollution. Personal noise dosimeters were used during 8-h working shifts. Data were collected from 126 employees using the 36-item 'A stress scale' and a socio-demographic information form. Results. The results of noise measurements exceeded World Health Organization and US Environmental Protection Agency recommended limits at all sites. The lowest Lex,8h (52 dB) was detected in the endocrinology clinic, while the highest (91 dB) was recorded in the podology unit. According to the stress scale scores, the lowest mean psychological symptom score (PsSS), physiological symptom score (PhSS) and total scale score (TSS) were observed in diagnostic units with 35 ± 14, 41 ± 14 and 76 ± 27, respectively, while the highest mean PsSS, PhSS and TSS were observed in the polyclinics with 44 ± 6, 64 ± 10 and 107 ± 10, respectively. The PsSS of employees exposed to noise (Lex,8h) above 75 dB was found to be higher than for other employees. Conclusion. Lex,8h above 75 dB can increase psychological symptoms in healthcare employees.

Reduced noise in the emergency department: the impact on staff well-being and room acoustics.

BACKGROUND AND INTRODUCTION: The ED is often perceived as noisy. Excessive noise has deleterious effects on health and productivity. This study evaluated if a package of noise-reducing interventions altered workload, physical complaints, productivity and room acoustics. METHODS: This was an observational pre-post implementation study. It was performed in our non-academic ED in the Netherlands from July 2021 to April 2022. Our primary objective was to determine if a combination of technical, acoustical and behavioural interventions was associated with improved staff well-being, and the secondary objective was to evaluate if these interventions resulted in better room acoustics. Moreover, the correlation of noise sensitivity with staff well-being and its effect on interventions were evaluated. All ED staff that were sufficiently exposed to the interventions received questionnaires to assess their well-being before and after the interventions. Room acoustics before and after interventions were expressed in reverberation time (seconds) and participant ratings are reflected as the mean of the sum of their Likert scale ratings. RESULTS: 43 participants were included. At baseline, individual noise sensitivity was significantly correlated with physical complaints (r=0.409, p=0.006) and productivity (r=0.399, p=0.008). After the interventions, a reduction in reverberation time was reached in the central ED area (0.49 s, SD 0.06 s vs 0.39 s, SD 0.05; p<0.001). Participants experienced significantly less noise disturbance during work (sum score 7.28 vs 3.19; p<0.001). Productivity and physical complaints improved significantly (sum score 4.81 vs 2.70; p<0.001 and sum score -3.74 vs -8.14; p<0.001, respectively). Participants also showed a perceived change in behaviour (sum score -2.00 vs -4.70; p<0.001). There was no confounding by noise sensitivity nor age. CONCLUSION: The package of behavioural, acoustical and technical interventions was associated with increased staff well-being, reflected by decreased perception of noise, increased productivity, decreased physical complaints and observable changes in behaviour. Furthermore, the interventions positively influenced the room acoustics.

[A study on the hearing protection and intervention effects of silicone earplug usage among manufacturing workers].

Objective: To assess the efficacy of silicone earplugs in protecting workers exposed to noise in a typical manufacturing environment, and to provide training interventions for workers who do not achieve the anticipated noise reduction levels, as well as examining the spectral characteristics of earplug attenuation. Methods: From June to August 2022, a total of 294 noise-exposed workers in two manufacturing enterprises equipped with the same type of earplug were studied by cluster sampling method, by conducting questionnaire surveys, collecting data, fitting tests, and providing trainings, the current noise exposure levels of workers in the industry as well as the perception about the earplug were understood. Additionally, the attenuation before and after intervention in workplace were measured, the spectral characteristics of noise reduction were were described and compared. Results: The percentage of workers with Personal Attenuation Rating (PAR) of 0 is 32.7% (96/294), and the baseline pass rates are all below 60%. There were no significant differences in pass rates based on gender, age, noise exposure, education level, or cognition of earplug effectiveness. After adjusting the way that earplugs are worn or changing the type of earplugs, all workers were able to meet their noise reduction requirements. The median PAR improvement for both companies is above 10 dB. The noise attenuation of the earplug vary with frequency, with lower attenuation at 4 000 Hz and higher attenuation at 8 000 Hz, showing some deviation from the nominal values. Conclusion: The difference between the actual sound attenuation value of earplugs and the nominal value is related to the noise frequency. When using silicone earplugs, attention should be paid to the spectral composition of the noise in the workplace.

Effect of Noise in the Emergency Department on Occupational Burnout and Resignation Intention of Medical Staff.

OBJECTIVE: This study aims to explore the effect of noise in the emergency department on the occupational burnout and the resignation intentions of medical staff. METHODS: This retrospective study selected 42 medical staff (group A) in the emergency department of our hospital from March 2020 to March 2021 and 39 medical staff (group B) in the rehabilitation department during the same period as research subjects. Noise levels in the daily working environment of medical staff were collected. The Maslach Burnout Inventory General Survey and Intent to Leave Scale was used to evaluate occupational burnout and resignation intention. A multivariate linear regression analysis was adopted to explore the effects of noise exposure level in the emergency department on occupational burnout and resignation intention. RESULTS: The scores of emotional fatigue, work apathy and sense of achievement in group A were higher than those in group B (P < 0.05), among which reverse scoring was adopted for sense of accomplishment. Group A had significantly higher scores of resignation intention I, resignation intention II and resignation intention III than group B (P < 0.001). The department of group A had significantly higher noise level than that of group B (P < 0.001). The Multivariate linear regression analysis showed that noise level in the emergency department was correlated with the occupational burnout and resignation intention of medical staff (all P < 0.05). CONCLUSIONS: The emergency department is exposed to a high noise level, which is correlated with the occupational burnout and resignation intentions of medical staff. Therefore, hospitals should give importance to noise exposure in the emergency departments and adopt positive coping strategies to reduce the effect of noise on medical staff and the resignation rate.

A Comprehensive Review of Auditory and Non-Auditory Effects of Noise on Human Health.

OBJECTIVE: Excessive noise is unpleasant and induces several physiological and psychological effects. Noise pollution is a potential threat to humans, particularly those continuously exposed for extended periods throughout the day over many years. This review aims to examine the various auditory and non-auditory outcomes associated with prolonged exposure to noise pollution. MATERIALS AND METHODS: The review utilized a combination of relevant keywords to search the electronic databases. After screening based on the applied selection criteria for title, abstract, and full text, 44 articles were finally selected for critical review. RESULTS: We identified and analyzed research findings related to noise-induced hearing loss, tinnitus, and sleep disturbances along with non-auditory issues such as annoyance, cognitive impairments, and mental stress associated with cardiovascular disorders. Furthermore, the existing studies were compared and collated to highlight the unique challenges and significance of noise pollution as a distinctive environmental concern and to explore the ongoing efforts in its research and prevention, including the early detection and potential reversal of noise-induced hearing loss. CONCLUSION: The fundamental health consequences of noise pollution underscore the need for extensive research encompassing emerging noise sources and technologies to establish a health management system tailored to address noise-related health concerns and reduce noise exposure risk among populations. Finally, further research is warranted to ensure improved measurement of noise exposure and related health outcomes, especially in the context of occupational noise.

Relationship Between Occupational Noise Exposure and Gestational Hypertension in Pregnant Women in Taizhou City: Cross-Sectional Study.

OBJECTIVE: In view of the hazards of occupational noise exposure, this study investigated the relationship between occupational noise exposure and gestational hypertension in Taizhou City, Zhejiang Province, China to provide inspiration and reference for reducing the occurrence of gestational hypertension. METHODS: This cross-sectional study analyzed the clinical data of 316 pregnant women in Taizhou City admitted to Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University from May 2020 to May 2023. In accordance with Acoustic Environment Quality Standards (GB3096-2008), 60 dB was used as the cut-off point. These pregnant women were divided into the low noise group (LNG, n = 161) and high noise group (HNG, n = 155) according to the noise exposure level in the working environment. This also study compared the noise exposure, blood pressure (BP), fasting blood glucose (FBG), blood lipid (BL), fetal size, and heart rate (HR), and analyzed the relationship of noise exposure with BP, FBG, BL, fetal size, HR, and occurrence of gestational hypertension. RESULTS: The HNG had higher noise exposure level (P < 0.001), BP, FBG, BL and HR (P < 0.001), larger fetal size (P < 0.001) and higher occurrence of gestational hypertension (P < 0.05) compared with the LNG. Correlation analysis showed that noise exposure level was positively correlated with BP, FBG, BL, HR, and fetal size (P < 0.001) and had the strongest association with gestational hypertension. CONCLUSION: Occupational noise exposure has adverse effects on pregnant women and fetuses. Pregnant women should pay attention to their exposure to occupational noise to prevent gestational hypertension. The results of this study must be further verified and generalized.

Association between exposure to metalworking fluid aerosols, occupational noise and chronic kidney disease: a cross-sectional study in China.

BACKGROUND: Chronic kidney disease (CKD) carries a high public health burden yet little is known about the relationship between metalworking fluid (MWF) aerosols, occupational noise and CKD. We aimed to explore the relationship between occupational MWF aerosols, occupational noise and CKD. METHODS: A total of 2,738 machinists were sampled from three machining companies in Wuxi, China, in 2022. We used the National Institute for Occupational Safety and Health (NIOSH) method 5524 to collect individual samples for MWF aerosols exposure, and the Chinese national standard (GBZ/T 189.8-2007) method to test individual occupational noise exposure. The diagnostic criteria for CKD were urinary albumin/creatinine ratio (UACR) of ≥ 30 mg/g and reduced renal function (eGFR < 60 mL.min- 1. 1.73 m- 2) lasting longer than 3 months. Smooth curve fitting was conducted to analyze the associations of MWF aerosols and occupational noise with CKD. A segmented regression model was used to analyze the threshold effects. RESULTS: Workers exposed to MWF aerosols (odds ratio [OR] = 2.03, 95% confidence interval [CI]: 1.21-3.41) and occupational noise (OR = 1.77, 95%CI: 1.06-2.96) had higher prevalence of CKD than nonexposed workers. A nonlinear and positive association was found between increasing MWF aerosols and occupational noise dose and the risk of CKD. When daily cumulative exposure dose of MWF aerosols exceeded 8.03 mg/m3, the OR was 1.24 (95%CI: 1.03-1.58), and when occupational noise exceeded 87.22 dB(A), the OR was 1.16 (95%CI: 1.04-1.20). In the interactive analysis between MWF aerosols and occupational noise, the workers exposed to both MWF aerosols (cumulative exposure ≥ 8.03 mg/m3-day) and occupational noise (LEX,8 h ≥ 87.22 dB(A)) had an increased prevalence of CKD (OR = 2.71, 95%CI: 1.48-4.96). MWF aerosols and occupational noise had a positive interaction in prevalence of CKD. CONCLUSIONS: Occupational MWF aerosols and noise were positively and nonlinearly associated with CKD, and cumulative MWF aerosols and noise exposure showed a positive interaction with CKD. These findings emphasize the importance of assessing kidney function of workers exposed to MWF aerosols and occupational noise. Prospective and longitudinal cohort studies are necessary to elucidate the causality of these associations.

Oxidative Stress Assessment of Noise Exposure in the Workers Using Hearing Protection in a Pressing Industry.

BACKGROUND AND OBJECTIVE: Exposure to noise by generation of free radicals causes oxidative stress in body. The aim of this study was the evaluation of oxidative stress in workers who have used hearing protection devices during working time. MATERIAL AND METHOD: Pressing workers (n=24) of a home appliance industry were studied using hearing protection devices to reduce noise exposure. Twenty two office staff (without exposure to noise) were considered as a control group. Two groups were matched for age, work experience and smoking. Exposure to noise was measured by dosimeter method at workstations. By obtaining 3 ml blood sample, Malondialdehyde levels, Thiol groups and total antioxidant capacity were evaluated in all subjects. RESULTS: Exposure to sound pressure level in pressing workers by considering the noise reduction factor of the earplug was observed in 77.65 dB with minimum 75.1 dB and Maximum 81.22 dB. Plasma thiol groups (0.076 (0.041-0.119) vs (0.110 (0.076-0.197), mmol/l P =0.0001) and total antioxidant capacity (361.33± 54.65 vs 414.14± 96.82, µmol/ml P = 0.026) in pressing workers significantly decreased than control group. Pearson correlation showed significant results between exposure to noise and oxidative stress parameters. CONCLUSION: Exposure to noise wave cause oxidative stress in different site of body. Oxidative stress is an intermediate way for different disease due to noise exposure. Reducing of noise exposure by earplug in pressing workers is not efficient protection for oxidative stress generation. Therefore, hearing protection devices are not a barrier to the harmful effects of noise in occupational exposure.

Relationship Between Work-Related Noise Exposure and Cognitive Impairment: A Cross-Sectional Study in China.

Background: Noise exposure and the risk of cognitive impairment are currently major public health issues. Objective: This study aimed to analyze the relationship between noise exposure and early impairment of cognitive function from the perspective of occupational epidemiology and to provide evidence for the long-term prevention and treatment of dementia in the context of aging. Methods: This study was conducted in China between May and August 2021. The independent variables were the type of hazardous factors, duration of noise exposure, perceived noise intensity, and cumulative noise exposure (CNE). The dependent variable was cognitive function, which was measured using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Multiple linear and logistic regression were used to analyze the relationship between noise exposure and cognitive function and to establish an effect curve. Results: The detection rates of cognitive dysfunction using the MMSE and MoCA were 1.1% and 36.2%, respectively. The predicted MMSE and MoCA scores showed a downward trend within the CNE value ranging from 90-140 dB.time. Each unit increase in CNE decreased cognitive function scores by 0.025 (0.037, 0.013) and 0.020 (0.037, 0.003) points,respectively. Conclusions: From the perspective of occupational epidemiology, these findings reveal a potential link between long-term noise exposure and early cognitive impairment.

Advancing noise management in aviation: Strategic approaches for preventing noise-induced hearing loss.

As urbanization and population growth escalate, the challenge of noise pollution intensifies, particularly within the aviation industry. This review examines current insights into noise-induced hearing loss (NIHL) in aviation, highlighting the risks to pilots, cabin crew, aircraft maintenance engineers, and ground staff from continuous exposure to high-level noise. It evaluates existing noise management and hearing conservation strategies, identifying key obstacles and exploring new technological solutions. While progress in developing protective devices and noise control technologies is evident, gaps in their widespread implementation persist. The study underscores the need for an integrated strategy combining regulatory compliance, technological advances, and targeted educational efforts. It advocates for global collaboration and policy development to safeguard the auditory health of aviation workers and proposes a strategic framework to enhance hearing conservation practices within the unique challenges of the aviation sector.

Cross-sectional study on the health of workers exposed to occupational noise in China.

OBJECTIVE: This study aimed to understand the health of workers exposed to occupational noise and explore the influencing factors related to workers' health, especially the impact of noise on workers' hearing. This work can provide a basis for formulating relevant measures for occupational noise prevention and control in the future. METHODS: On the basis of the key occupational disease monitoring project in Chongqing, China, in 2021, the data of 1125 workers exposed to occupational noise were analyzed. Data included demographic information, occupational history, clinical physical examination information, and noise detection information of the working environment. Chi-square test and multifactorial logistic regression were used for statistical analysis. RESULTS: The prevalence rates of abnormal electrocardiogram (ECG), blood pressure (BP), and pure tone audiometry (PTA) were 21.9% (246/1125), 27.8% (313/1125), and 18.0% (202/1125), respectively. Male workers accounted for 78.8%. Compared with male workers, female workers had a lower prevalence of abnormal PTA (OR = 0.28, 95% CI = 0.16-0.50). Workers working in medium enterprises had a lower prevalence of abnormal BP than workers in micro enterprises (OR = 0.36, 95% CI = 0.19-0.66). The prevalence of abnormal BP and PTA of workers increased with age. After adjusting for age, sex, and body mass index, the prevalence of abnormal ECG of mining workers was higher than that of manufacturing workers (OR = 1.54, 95% CI = 1.07-2.24), and the prevalence of abnormal PTA had a rising trend with the increase in noise exposure value. CONCLUSION: Noise-exposed workers have a high prevalence of abnormal ECG, BP, and PTA, and factors such as age, enterprise size, and workplace noise exposure are correlated with the aberrant health of workers. Governments, enterprises, and individuals need to attach great importance to the possible adverse effects of noise. They must also actively adopt various effective measures to protect the occupational safety and health of workers.

Risk analysis of noise-induced hearing loss of workers in the automobile manufacturing industries based on back-propagation neural network model: a cross-sectional study in Han Chinese population.

OBJECTIVES: This study aims to predict the risk of noise-induced hearing loss (NIHL) through a back-propagation neural network (BPNN) model. It provides an early, simple and accurate prediction method for NIHL. DESIGN: Population based, a cross sectional study. SETTING: Han, China. PARTICIPANTS: This study selected 3266 Han male workers from three automobile manufacturing industries. PRIMARY OUTCOME MEASURES: Information including personal life habits, occupational health test information and occupational exposure history were collected and predictive factors of NIHL were screened from these workers. BPNN and logistic regression models were constructed using these predictors. RESULTS: The input variables of BPNN model were 20, 16 and 21 important factors screened by univariate, stepwise and lasso-logistic regression. When the BPNN model was applied to the test set, it was found to have a sensitivity (TPR) of 83.33%, a specificity (TNR) of 85.92%, an accuracy (ACC) of 85.51%, a positive predictive value (PPV) of 52.85%, a negative predictive value of 96.46% and area under the receiver operating curve (AUC) is: 0.926 (95% CI: 0.891 to 0.961), which demonstrated the better overall properties than univariate-logistic regression modelling (AUC: 0.715) (95% CI: 0.652 to 0.777). The BPNN model has better predictive performance against NIHL than the stepwise-logistic and lasso-logistic regression model in terms of TPR, TNR, ACC, PPV and NPV (p<0.05); the area under the receiver operating characteristics curve of NIHL is also higher than that of the stepwise and lasso-logistic regression model (p<0.05). It was a relatively important factor in NIHL to find cumulative noise exposure, auditory system symptoms, age, listening to music or watching video with headphones, exposure to high temperature and noise exposure time in the trained BPNN model. CONCLUSIONS: The BPNN model was a valuable tool in dealing with the occupational risk prediction problem of NIHL. It can be used to predict the risk of an individual NIHL.

Noise exposure assessment of workers inspecting construction machinery vehicles in the Republic of Korea.

Previous studies have investigated the health hazards caused by exposure to the noise of heavy equipment used at construction sites. Korea's Ministry of Land, Infrastructure, and Transport operates a registration system for construction machinery, and regular safety inspections are mandatory. Although workers inspecting construction machinery vehicles are exposed to unwanted noise, no noise exposure assessment has been made regarding these workers in Korea. The time-weighted average (TWA) daily average noise exposure level among construction machinery inspectors at 18 inspection centers was 75.3 dB(A). Among the inspection steps, the exhaust gas inspection step was found to exhibit the highest noise exposure level, up to 100 dB(A). In Korea, if the noise level of a workplace exceeds 85 dB(A) as a TWA, workers are required to undergo special medical examinations. This study found that special medical examinations were required for two of the 18 target inspection centers (approximately 115 workers) as the 8-hour TWA noise level exceeded 85 dB(A). Therefore, regular noise exposure assessment and special medical examinations for noise are required to prevent inspectors from developing hearing disorders due to noise exposure.

Face the (unamplified) music: Key findings for musicians.

Music is complex. There are risks to hearing health associated with playing due to excessive sound exposure. Face the Music is an on-going cross-sectional project to assess the risks to unamplified classical musicians. Key findings over the first fifteen years are presented based on the research undertaken with a leading conservatoire on more than 5000 classical music students. The work covers hearing health surveillance, education and awareness, sound exposure, and new technology. The future of the research programme is discussed along with opportunities in objective hearing health assessment and new acoustic solutions. A lot has changed in fifteen years, but the research was driven by a change in United Kingdom legislation. It is hoped that the research results can inform future regulation.

Hearing protection field attenuation estimation systems and associated training for reducing workers' exposure to noise.

BACKGROUND: Global Burden of Disease studies identify hearing loss as the third leading cause of years lived with a disability. Their estimates point to large societal and individual costs from unaddressed hearing difficulties. Workplace noise is an important modifiable risk factor; if addressed, it could significantly reduce the global burden of disease. In practice, providing hearing protection devices (HPDs) is the most common intervention to reduce noise exposure at work. However, lack of fit of HPDs, especially earplugs, can greatly limit their effectiveness. This may be the case for 40% of users. Testing the fit and providing instructions to improve noise attenuation might be effective. In the past two decades, hearing protection fit-test systems have been developed and evaluated in the field. They are called field attenuation estimation systems. They measure the noise attenuation obtained by individual workers using HPDs. If there is a lack of fit, instruction for better fit is provided, and may lead to better noise attenuation obtained by HPDs. OBJECTIVES: To assess: (1) the effects of field attenuation estimation systems and associated training on the noise attenuation obtained by HPDs compared to no instruction or to less instruction in workers exposed to noise; and (2) whether these interventions promote adherence to HPD use. SEARCH METHODS: We used CENTRAL, MEDLINE, five other databases, and two trial registers, together with reference checking, citation searching, and contact with study authors to identify studies. We imposed no language or date restrictions. The latest search date was February 2024. SELECTION CRITERIA: We included randomised controlled trials (RCTs), cluster-RCTs, controlled before-after studies (CBAs), and interrupted time-series studies (ITSs) exploring HPD fit testing in workers exposed to noise levels of more than 80 A-weighted decibels (or dBA) who use hearing protection devices. The unit 'dBA' reports on the use of a frequency-weighting filter to adjust sound measurement results to better reflect how human ears process sound. The outcome noise attenuation had to be measured either as a personal attenuation rating (PAR), PAR pass rate, or both. PAR pass rate is the percentage of workers who passed a pre-established level of sufficient attenuation from their HPDs, identified on the basis of their individual noise exposure. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility, risk of bias, and extracted data. We categorised interventions as fit testing of HPDs with instructions at different levels (no instructions, simple instructions, and extensive instructions). MAIN RESULTS: We included three RCTs (756 participants). We did not find any studies that examined whether fit testing and training contributed to hearing protector use, nor any studies that examined whether age, gender, or HPD experience influenced attenuation. We would have included any adverse effects if mentioned by the trial authors, but none reported them. None of the included studies blinded participants; two studies blinded those who delivered the intervention. Effects of fit testing of HPDs with instructions (simple or extensive) versus fit testing of HPDs without instructions Testing the fit of foam and premoulded earplugs accompanied by simple instructions probably does not improve their noise attenuation in the short term after the test (1-month follow-up: mean difference (MD) 1.62 decibels (dB), 95% confidence interval (CI) -0.93 to 4.17; 1 study, 209 participants; 4-month follow-up: MD 0.40 dB, 95% CI -2.28 to 3.08; 1 study, 197 participants; both moderate-certainty evidence). The intervention probably does not improve noise attenuation in the long term (MD 0.15 dB, 95% CI -3.44 to 3.74; 1 study, 103 participants; moderate-certainty evidence). Fit testing of premoulded earplugs with extensive instructions on the fit of the earplugs may improve their noise attenuation at the immediate retest when compared to fit testing without instructions (MD 8.34 dB, 95% CI 7.32 to 9.36; 1 study, 100 participants; low-certainty evidence). Effects of fit testing of HPDs with extensive instructions versus fit testing of HPDs with simple instructions Fit testing of foam earplugs with extensive instructions probably improves their attenuation (MD 8.62 dB, 95% CI 6.31 to 10.93; 1 study, 321 participants; moderate-certainty evidence) and also the pass rate of sufficient attenuation (risk ratio (RR) 1.75, 95% CI 1.44 to 2.11; 1 study, 321 participants; moderate-certainty evidence) when compared to fit testing with simple instructions immediately after the test. This is significant because every 3 dB decrease in noise exposure level halves the sound energy entering the ear. No RCTs reported on the long-term effectiveness of the HPD fit testing with extensive instructions. AUTHORS' CONCLUSIONS: HPD fit testing accompanied by simple instructions probably does not improve noise attenuation from foam and premoulded earplugs. Testing the fit of foam and premoulded earplugs with extensive instructions probably improves attenuation and PAR pass rate immediately after the test. The effects of fit testing associated with training to improve attenuation may vary with types of HPDs and training methods. Better-designed trials with larger sample sizes are required to increase the certainty of the evidence.