Statistical estimation of noise induced hearing loss among the drivers in one of the most polluted cities of India.

In the present study, an attempt has been made to assess the impact of vehicular noise upon the 3-wheeler tempo drivers and to know whether there is any relationship between hearing loss and cumulative noise exposure. For this purpose, 3-wheeler tempo drivers (Exposed group) and non-commercial light motor vehicle car drivers (Unexposed group) were chosen as study subjects. Three traffic routes were selected to assess the noise level during waiting and running time in the exposed and unexposed groups. Among all three routes, the highest mean noise level (Leq) was observed on the Chowk to Dubagga route for waiting and en-route noise measurement. It was measured as 84.13 dB(A) and 86.36 dB(A) for waiting and en-route periods of 7.68 ± 3.46 and 31.05 ± 6.6 min, respectively. Cumulative noise exposure was found to be significantly different (p < 0.001) in all age groups of exposed and unexposed drivers. Audiometric tests have been performed over both exposed and unexposed groups. The regression analysis has been done keeping hearing loss among tempo drivers as the dependent variable and age (years) and Energy (Pa2 Hrs) as the independent variable using three different criteria of hearing loss definitions, i.e., World Health Organization, National Institute for Occupational Safety and Health (NIOSH), Occupational Safety and Health Administration criteria. Among these three criteria, the NIOSH criterion of hearing loss best explained the independent variables. It could explain the total variation in dependent variable by independent variable quite well, i.e., 68.1%. The finding showed a linear relationship between cumulative noise exposures (Pa2 Hrs) and the exposed group's hearing loss (dB), i.e., hearing loss increases with increasing noise dose. Based on the findings, two model equations were developed to identify the safe and unsafe noise levels with exposure time.

Sensitivity of Methods for Diagnosing Noise-Induced Hearing Loss in Cases of Exposures Including Intense Low-Frequency Noise.

Exposure to intense low-frequency sounds, for example inside tanks and armoured vehicles, can lead to noise-induced hearing loss (NIHL) with a variable audiometric pattern, including low- and mid-frequency hearing loss. It is not known how well existing methods for diagnosing NIHL apply in such cases. Here, the audiograms of 68 military personnel (mostly veterans) who had been exposed to intense low-frequency noise (together with other types of noise) and who had low-frequency hearing loss (defined as a pure-tone average loss at 0.25, 0.5 and 1 kHz ≥20 dB) were used to assess the sensitivity of three diagnostic methods: the method of Coles, Lutman and Buffin, denoted CLB, which depends on the identification of a notch or bulge in the audiogram near 4 kHz, and two methods specifically intended for diagnosing NIHL sustained during military service, the rM-NIHL method, which depends on the identification of a notch or bulge in the audiogram near 4 kHz and/or a hearing loss at high frequencies greater than expected from age alone, and the MLP(18) method based on a multi-layer perceptron. The proportion of individuals receiving a positive diagnosis for either or both ears, which provides an approximate measure of sensitivity, was 0.40 for the CLB method, 0.79 for the rM-NIHL method and 1.0 for the MLP(18) method. It is concluded that the MLP(18) method is suitable for diagnosing NIHL sustained during military service whether or not the exposure includes intense low-frequency sounds.

Impact of occupational noise exposure on the hearing level in hospital staffs: a longitudinal study.

The study aimed to evaluate the impact of occupational noise on hearing loss among healthcare workers using audiometry. A longitudinal study was conducted with a six-month follow-up period in a hospital with 21 participants, divided into high-noise-exposure (HNE) and low-noise-exposure (LNE) groups. Mean noise levels were higher in the HNE group (70.4 ± 4.5 dBA), and hearing loss was measured using pure-tone audiometry at baseline and follow-up. The HNE group had significantly higher mean threshold levels at frequencies of 0.25 kHz, 0.5 kHz, 4.0 kHz, and an average of 0.5, 1, 2, and 4 kHz (all p-values < 0.05) after the follow-up period. After adjusting for confounding factors, the HNE group had significantly higher hearing loss levels at 0.25 kHz, 0.5 kHz, and average frequencies of 0.5, 1, 2, and 4 kHz compared to the LNE group at the second measurement. Occupational noise levels above 65 dBA over six months were found to cause significant threshold changes at frequencies of 0.25 kHz, 0.5 kHz, and an average of 0.5-4.0 kHz. This study highlights the risk of noise-induced hearing loss among healthcare workers and emphasizes the importance of implementing effective hearing conservation programs in the workplace. Regular monitoring and assessment of noise levels and hearing ability, along with proper use of personal protective equipment, are crucial steps in mitigating the impact of occupational noise exposure on the hearing health of healthcare workers.

Noise-Induced Hearing Loss and Use of Hearing Protection Awareness among Medical Students in Saudi Arabia: Mixed Qualitative and Quantitative Study.

BACKGROUND: Noise-Induced Hearing Loss (NIHL) is a prevalent occupational hazard among healthcare professionals, including medical students. Despite its detrimental effects, the awareness and utilization of hearing protection measures among medical students in Saudi Arabia remain understudied. OBJECTIVE: Is to determine the level of awareness and understanding of NIHL among medical students in Saudi Arabia, as well as their knowledge and usage of hearing protection measures and to identify potential barriers and facilitators for hearing protection utilization. METHODS: A mixed-methods approach was employed, involving a questionnaire survey and semi-structured interviews. The survey collected data on demographics, knowledge of NIHL, and hearing protection practices among medical students. Subsequently, a semi-structured interview was conducted to obtain in-depth insights into the students' experiences, attitudes, and beliefs regarding NIHL and the use of hearing protection. RESULTS: The level about NIHL was 59.32%. Better access to information is associated with increased odds of awareness (odds ratio=3.07, p=0.012). Having relatives with hearing loss increases the odds of awareness (odds ratio =2.49, p=0.034). Individuals with hearing loss or impairment have higher odds of awareness (odds ratio =2.27, p=0.046). Ear Pain, temporary hearing loss, tinnitus, or ringing in the ear: These factors are not significantly associated with awareness of noise-induced hearing loss (p>0.05). Using hearing aids is strongly associated with increased odds of awareness (odds ratio =3.94, p=0.006).The quantitative analysis provided statistical information on the prevalence rates and factors influencing hearing protection usage, while the qualitative analysis uncover nuanced perspectives and experiences. CONCLUSION: This research will contribute to the understanding of NIHL and hearing protection practices among medical students in Saudi Arabia. Improving hearing protection awareness and practices among medical students can ultimately reduce the incidence of NIHL and promote a healthier work environment within the healthcare sector.

Prevalence and predictors of high-frequency hearing loss among mine workers in Gujarat, western India: a cross-sectional study on the need to implement a comprehensive hearing conservation program.

BACKGROUND: High-frequency hearing loss (HFHL) stands as a prevalent occupational morbidity globally, with numerous associated risk factors, some of which are modifiable. In the context of a comprehensive hearing conservation program, the initial steps involve early screening and identification of workers with these modifiable risk factors, aiming to reduce the prevalence of hearing loss. Our objective was to estimate the prevalence of HFHL and determine its predictors among mine workers. METHODS: We conducted a cross-sectional study among 226 mine workers in ten open-cast mines in Gujarat state, the western part of India, in November 2020. We collected data on socio-demography, addiction, occupation history and comorbidities, along with anthropometric, blood pressure, and blood sugar measurements. Audiometric evaluations using a portable diagnostic audiometer were employed to assess HFHL, defined as a hearing threshold exceeding 25 decibels (dB) at high frequencies (3000, 4000, 6000, and 8000 Hz). A generalized linear model (GLM) with a binomial family was performed to determine the predictors significantly predicting HFHL after adjusting for confounding variables. RESULTS: The prevalence of HFHL was 35% (95% CI: 29-42%) in our study setting. Office workers demonstrated a prevalence of 19%, whereas other job categories displayed a higher prevalence of 42%, resulting in a significant prevalence difference of 23% and a prevalence ratio of 2.2. The GLM analysis revealed that variables, such as noise exposure during work [adjusted prevalence ratio (aPR) 2.3 (95% CI: 1.2-4.7, p = 0.018)] and noise exposure duration [aPR 1.1 (95% CI: 1.0-1.1, p = 0.042)], were significant predictors of HFHL. CONCLUSIONS: In our study setting, mine workers exhibited a high prevalence of HFHL, with exposure to workplace noise and duration being modifiable predictors. Because HFHL advances slowly and is generally undetected by the individual, we recommend periodic testing using audiometry to identify it among mine workers and, if possible, shifting them from mining activities to office. Furthermore, we advocate for the implementation of a comprehensive hearing conservation program to the extent possible.

Associations Between Recreational Noise Exposure and Hearing Function in Adolescents and Young Adults: A Systematic Review.

PURPOSE: There is an increasing concern regarding hazardous recreational noise exposure among adolescents and young adults. Daily exposure to loud sound levels over a long period of time can increase the risk of noise-induced hearing loss. The full extent of the impact of recreational noise on hearing is not yet fully understood. The purpose of this review was to synthesize research that investigated hearing function in relation to recreational noise exposure in adolescents and young adults. METHOD: A systematic literature search of five databases covering the years 2000-2023 was performed. The articles included investigated audiological measurements of hearing function in relation to recreational noise exposure. RESULTS: Four hundred sixty records were identified, of which 20 met the inclusion criteria and were included in the results. This review showed that although some recreational noise activities can be potentially harmful, there is an unclear relationship between exposure and outcome. Some findings indicated hearing threshold shifts or reduced otoacoustic emission amplitudes after recreational noise exposure, but most changes were short term and in the extended high-frequency range. CONCLUSIONS: There seemed to be inconsistencies regarding the utilization of methods of measuring exposure and outcome between studies. This might be one reason for the differing results in studies on the reported impact on hearing function from recreational noise exposure. To draw more certain conclusions about long-term effects, there is a need for longitudinal research that utilizes sound level measurements to assess low and high degrees of recreational noise exposure in relation to hearing function. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25114193.

[Study on the fit testing for the workers wearing hearing protection device in machinery manufacturing enterprises].

Objective: To investigate the occupational noise hazards in five machinery manufacturing enterprises, and to evaluate the individual noise reduction values and influencing factors of workers wearing hearing protection device (HPD) by individual fit testing. Methods: From November 2021 to January 2022, 5 machinery manufacturing enterprises in Bao'an District of Shenzhen were selected to conduct an occupational health survey to understand the noise exposure level of workers. The 3MTM E-A-RfitTM fitness test system was used to test the baseline individual sound attenuation value level (PAR) of the daily wear of the ear protecters for 485 workers in typical noise working positions. Workers whose PAR values could not meet the requirements of noise reduction at work were instructed to wear and repeated tests were conducted. PAR results of the workers before and after the intervention were collected and analyzed. Results: The noise workers who received the suitability test were mainly distributed in 24 types of work, the job noise exposure level was 80.2 dB (A) ~ 95.0 dB (A), and the job noise excess rate was 52.5% (138/263). The median baseline PAR [M (Q(1), Q(3)) ] for 485 workers was 6.0 (0.0, 14.0) dB. The baseline PAR of male workers, those with more than 15 years of working experience, those with more than 15 years of using ear guards, those who considered ear guards comfortable to wear, those with college degree or above, and those exposed to noise level 90 dB (A) were higher, and the difference was statistically significant (P<0.05). A total of 275 workers (56.7%) did not pass the baseline PAR test, and there was no statistically significant difference in the intervention rate of workers in different noise groups (P>0.05). PAR in subjects who did not pass baseline after intervention increased from 0.0 (0.0, 3.0) dB to 15.0 (12.0, 18.2) dB. Conclusion: The workplace noise hazard of machinery manufacturing enterprises is serious, and there is a great difference between the baseline PAR and the nominal value of the hearing guard worn by the noise exposed workers. The intervention measures can effectively improve the protective effect of wearing ear protectors.

Association of noise exposure, plasma microRNAs with metabolic syndrome and its components among Chinese adults.

AIMS: We aimed to evaluate the association of occupational noise with metabolic syndrome (MetS) and its components, and to assess the potential role of miRNAs in occupational noise-associated MetS. METHODS: A total of 854 participants were enrolled in our study. Cumulative noise exposure (CNE) was estimated in conjunction with workplace noise test records and research participants' employment histories. Logistic regression models adjusted for potential confounders were used to assess the association of CNE and miRNAs with MetS and its components. RESULTS: We observed linear positive dose-response associations between occupational noise exposure and the prevalence of MetS (OR: 1.031; 95 % CI: 1.008, 1.055). And linear and nonlinear relationship were also found for the association of occupational noise exposure with high blood pressure (OR: 1.024; 95 % CI: 1.007, 1.041) and reduced high-density lipoprotein (OR: 1.051; 95 % CI: 1.031, 1.072), respectively. MiR-200a-3p, miR-92a-3p and miR-21-5p were inversely associated with CNE, or the prevalence of MetS and its components (all P < 0.05). However, we did not find any statistically significant mediation effect of miRNAs in the associations of CNE with MetS. Furthermore, the prevalence of bilateral hearing loss in high-frequency increased (OR: 1.036; 95 % CI: 1.008, 1.067) with CNE level rising, and participants with bilateral hearing loss in high-frequency had a significantly higher risk of MetS (OR: 1.727; 95 % CI: 1.048, 2.819). CONCLUSION: Our study suggests that occupational noise exposure is associated with MetS and its components, and the role of miRNAs in noise-induced increasing MetS risk needs to be confirmed in future studies.

Interactions of genetic variations in FAS, GJB2 and PTPRN2 are associated with noise-induced hearing loss: a case-control study in China.

BACKGROUND: This study aimed to screen and validate noise-induced hearing loss (NIHL) associated single nucleotide polymorphisms (SNPs), construct genetic risk prediction models, and evaluate higher-order gene-gene, gene-environment interactions for NIHL in Chinese population. METHODS: First, 83 cases and 83 controls were recruited and 60 candidate SNPs were genotyped. Then SNPs with promising results were validated in another case-control study (153 cases and 252 controls). NIHL-associated SNPs were identified by logistic regression analysis, and a genetic risk model was constructed based on the genetic risk score (GRS), and classification and regression tree (CART) analysis was used to evaluate interactions among gene-gene and gene-environment. RESULTS: Six SNPs in five genes were significantly associated with NIHL risk (p < 0.05). A positive dose-response relationship was found between GRS values and NIHL risk. CART analysis indicated that strongest interaction was among subjects with age ≥ 45 years and cumulative noise exposure ≥ 95 [dB(A)·years], without personal protective equipment, and carried GJB2 rs3751385 (AA/AB) and FAS rs1468063 (AA/AB) (OR = 10.038, 95% CI = 2.770, 47.792), compared with the referent group. CDH23, FAS, GJB2, PTPRN2 and SIK3 may be NIHL susceptibility genes. CONCLUSION: GRS values may be utilized in the evaluation of the cumulative effect of genetic risk for NIHL based on NIHL-associated SNPs. Gene-gene, gene-environment interaction patterns play an important role in the incidence of NIHL.

Long-Term Hearing Loss after Acute Acoustic Trauma in the French Military: A Retrospective Study.

INTRODUCTION: Acute acoustic trauma (AAT) is characterized by cochlea-vestibular signs following intense noise exposure, often caused by impulse noise. French military faces a high risk of AAT because of the use of weapons with peak sound levels exceeding 150 dB. Hearing loss (HL) resulting from AAT can have a significant impact on quality of life and operational capacity. The aim of this study was to assess the prevalence of long-term hearing impairment after AAT. MATERIALS AND METHODS: The study involved a retrospective review of computer-based patient records from four military medical centers in Northeast France between January 2016 and December 2021. The inclusion criteria required the presence of cochlea-vestibular signs following impulse acoustic exposure and the absence of other causes. Sociodemographic and clinical data were collected, including audiometric data before and after exposure. The primary end point was the presence of a threshold elevation greater than 10 dB between reference and late audiograms. RESULTS: A total of 419 patients were included in the analysis, with a majority of males (n = 419; 84.7%) and a mean age of 23.6 yrs. The most common causative agent was the 5.56-mm assault rifle (n = 327; 78.0%). Tinnitus was the most frequent symptom (n = 366; 87.4%), followed by hypoacusis (n = 147; 35.1%) and earache (n = 89; 21.2%). The initial audiograms showed no HL in 31.0% of cases, while the mean deficit across all frequencies was 15.4 dB. All patients received corticosteroid therapy, with a mean duration of 6.0 d. Late audiograms conducted at an average interval of 448.0 d after AAT revealed a prevalence of long-term HL exceeding 20%. Higher doses of corticosteroid therapy (>1 mg/kg) were associated with a reduced frequency of long-term HL. CONCLUSIONS: This study highlights the prevalence of long-term hearing impairment after AAT in the French military. The findings emphasize the importance of preventive measures, including proper use of hearing protection devices, and the need for timely diagnosis and treatment. Further research is warranted to explore gender susceptibility to AAT and evaluate the impact of different weapons on AAT characteristics. The study also underscores the potential benefits of higher doses of corticosteroid therapy in reducing the risk of long-term hearing impairment. Overall, the findings contribute to a better understanding of AAT and can inform strategies for its prevention and management in military settings.

New Paradigm of Music Listening: Hearing Protection Perceptions and Treatment Decision-Making Among Music Venue Attendees.

OBJECTIVE: Investigate the prevalence of hearing protection (HP) use and behavioral motivations and barriers among adults attending music venues. STUDY DESIGN: Cross-sectional online survey study. SETTING: Noise exposure levels at popular social music venues often exceed national guidelines. METHODS: Surveys were distributed on online music communities. Respondents (n = 2352) were asked about demographics, HP use at music venues, knowledge about noise exposure impact, and perceptions of HP use. Data were characterized through descriptive statistics. Multivariable regression analysis explored differences in knowledge and perception between HP users and nonusers. RESULTS: In this cohort (mean age 29 ± 7 years, 61% male), HP users were significantly more aware of the impact of music venues on hearing (P < .01), believed their hearing ability had decreased after attending music venues (P < 0.01), and believed HP could protect from hearing loss (P < .01) than non-HP users. HP nonusers most frequently cited never considering HP (14.45%) and apathy about it affecting music quality (12.71%). Common sources of HP information were recommended by a friend/peer. Multivariable regression analysis accounting for demographics, medical history, and attendance characteristics found belief that HP use at music venues could protect from hearing loss (ß = 0.64, 95% confidence interval [CI] = [0.49-0.78]) and HP use (ß = 1.73, 95% CI = [1.47-1.98]) were significantly associated with increased subjective enjoyment while wearing HP. CONCLUSION: HP users and nonusers have significantly different perceptions of HP use and its impact. Our findings have implications for understanding motivations and barriers related to HP use and developing strategies to promote HP use at music venues.

No accelerated 20-year hearing decline after occupational noise exposure has ceased: The HUNT study.

OBJECTIVES: It has been suggested that noise exposure can accelerate hearing decline after the noise exposure has ceased. We aimed to assess long-term hearing decline in persons with and without prior occupational noise exposure. METHODS: We conducted a population-based longitudinal study in Norway using the Trøndelag Health Study (HUNT) from 1996 to 1998 (baseline) and from 2017 to 2019 (follow-up). The sample included 1648 participants with baseline age ≥55 years (42% men, mean age 60 years) and <5 years occupational noise exposure after baseline. We analyzed the association between occupational noise exposure before baseline and mean hearing decline between 1998 and 2018 (20-year decline) at each frequency, adjusted for age, sex, education, and impulse noise exposure before baseline. RESULTS: Occupational noise exposure before baseline (N = 603) was associated with baseline hearing loss, but not with later accelerated 20-year decline, at any frequency. Noise-exposed persons had less subsequent 20-year decline at 3 kHz than did nonexposed. Restricting the noise-exposed group to persons who also had a baseline Coles notch (hearing thresholds at 3, 4, or 6 kHz of 10 dB or more compared with thresholds at 1 or 2 kHz and 6 or 8 kHz; N = 211), the exposed group showed less 20-year decline at both 3 and 4 kHz, as well as less accelerated 20-year decline at 8 kHz, compared with the nonexposed. CONCLUSION: Our large long-term longitudinal study shows no increased risk of continuing hearing decline after occupational noise exposure has ceased. The finding supports a conclusion that ear damage stops when the noise exposure is ended.

Association between occupational noise and obesity: a retrospective cohort study in China.

OBJECTIVES: To determine the relationship between occupational noise, and obesity and body mass index (BMI) changes. METHODS: Baseline data were collected from participants (n = 1264) who were followed for 6 years in a retrospective study. The noise exposure level (LAeq,8h) was determined by equivalent continuous weighted sound pressure levels using the fixed-point surveillance method for noise monitoring. The cumulative noise exposure (CNE) level was determined using the equal energy formula, which is based on exposure history and level. RESULTS: The incidence of obesity at low (RR = 2.364, 95% CI 1.123-4.739]), medium (RR = 3.921, 95% CI 1.946-7.347]), high (RR = 5.242, 95% CI 2.642-9.208]), and severe noise levels (RR = 9.322, 95% CI 5.341-14.428]) was higher risk than the LAeq,8h control level. The risk of obesity among participants exposed to low (RR = 2.957, 95% CI 1.441-6.068]) and high cumulative noise levels (RR = 7.226, 95% CI 3.623-14.415]) was greater than the CNE control level. For every 1 dB(A) increase in LAeq,8h, the BMI increased by 0.063 kg/m2 (95% CI 0.055-0.071], SE = 0.004). For every 1 dB(A) increase in the CNE, the BMI increased by 0.102 kg/m2 (95% CI 0.090-0.113], SE = 0.006). CONCLUSIONS: Occupational noise is related to the incidence of obesity. The occupational noise level and occupational noise cumulative level were shown to be positively correlated with an increase in BMI.

[The studies of problem of professional hearing loss in crew members of water vessels].

The hearing loss is one of the significant problems in the world. The disease can develop both for genetic reasons and under influence of external factors at work. The noise is the main indicator of occupational risk of hearing loss. Due to influence of noise and vibration, in certain crew members of water vessel develops professional sensorineural hearing loss that subsequently prevents signing of employment contract and continuation of work at sea. This circumstance confirms actuality of stated problematic. The article presents types of sensorineural hearing loss depending on classification criterion. The features of professional activities of seafarers in conditions of strong noise exposure are revealed. The methods of identifying hearing defects in ship crew members are determined. The advisable measures to protect hearing health and to prevent deafness are formulated.

Investigation of critical factors influencing the underestimation of hearing loss predicted by the ISO 1999 predicting model.

OBJECTIVE: To analyze factors influencing the underestimation of noise-induced permanent threshold shift (NIPTS) among manufacturing workers, providing baseline data for revising noise exposure standard. DESIGN: A cross-sectional study was designed with 2702 noise-exposed workers from 35 enterprises from 10 industries. Personal noise exposure level(LAeq,8h) and noise kurtosis level were determined by a noise dosimeter. Questionnaires and hearing loss tests were performed for each subject. The predicted NIPTS was calculated using the ISO 1999:2013 model for each participant, and the actual measured NIPTS was corrected for age and sex. The factors influencing the underestimation of NIPTS were investigated. RESULTS: The predicted NIPTS at each test frequency (0.5, 1, 2, 3, 4, or 6kHz) and mean NIPTS at 2, 3, 4, and 6kHz (NIPTS2346) using the ISO 1999:2013 model were significantly lower than their corresponding measured NIPTS, respectively (P < 0.001). The ISO model significantly underestimated the NIPTS2346 by 12.36 dB HL. The multiple linear regression analysis showed that noise exposure level, exposure duration, age, and kurtosis could affect the degree of underestimation of NIPTS2346. The generalized additive model (GAM) with (penalized) spline components showed nonlinear relationships between critical factors (age, exposure duration, noise level, and kurtosis) and the underestimated NIPTS2346.The underestimated NIPTS2346 decreased with an increase in exposure duration (especially over ten years). There was no apparent trend in the underestimated NIPTS2346 with age. The underestimated NIPTS2346 decreased with the increased noise level [especially > 90 dB(A)]. The underestimated NIPTS2346 increased with an increase in noise kurtosis after adjusting for the noise exposure level and exposure duration and ultimately exhibiting a linear regression relationship. CONCLUSIONS: The ISO 1999 predicting model significantly underestimated the noise-induced hearing loss among manufacturing workers. The degree of underestimation became more significant at the noise exposure condition of fewer than ten years, less than 90 dB(A), and higher kurtosis levels. It is necessary to apply kurtosis to adjust the underestimation of hearing loss and consider the applying condition of noise energy metrics when using the ISO predicting model.

A current affair: worker perceptions of noise exposure and occupational hearing loss in Australian coal mines.

BACKGROUND: The objective of the online survey was to determine worker attitudes towards, perceptions on hearing loss, and management of workplace noise; and to identify barriers within current strategies that prevent effective management of hearing health in Australian mines. DESIGN: This cross-sectional study utilized a modified survey design, initially designed for use by Safe Work Australia for a broader study published in 2010. STUDY SAMPLE: The survey questionnaire was made available online to volunteer participants, recruited with the assistance of State and National Health and Safety, and mining organizations. Volunteer participants were required to be proficient in English, be employed by an Australian underground or open cut mine, including coal processing plants; or work as a contractor on one of the specified mine sites. All mining employees, regardless of occupation, job title, and occupational hearing loss classification or status, were invited to complete the questionnaire. RESULTS: Almost 60% of respondents indicated that they had high noise exposure for than 10 yr or more, and have some trouble hearing, mostly associated with infrequent tinnitus. Nearly 71% of these workers believe that the noise control strategies in their workplaces are effective, but this mostly refers to the use of hearing protection devices. CONCLUSION: The results indicate that general knowledge on the cause and effect of noise exposure in the workplace is well understood. However, due to the long latency associated with the development of noise-induced hearing loss (NIHL), there is an issue urgency in terms of risk management. It is surprising that most of the respondents recommended more inspections and administrative controls, especially since most respondents were health, safety, and environment (HSE) professionals. HSE professionals should be advocating for higher order, more permanent solutions, and not purely administrative controls and personal protective equipment. These findings raise the question of whether there is a multifaceted working-culture issue that needs to be addressed, in combination with higher order control implementation.

Noise-induced hearing loss among manufacturing factory workers in Kuching, Sarawak: Prevalence and associated risk factors.

INTRODUCTION: Noise-induced hearing loss (NIHL) is a common problem worldwide. Increased globalisation, as well as industrialisation, gives rise to an increase in the incidence of NIHL worldwide. Malaysia is not spared from this problem, either. The objectives were to determine the prevalence of NIHL and its associated factors among manufacturing factory workers. MATERIAL AND METHODS: A cross-sectional study was done in Kuching, Sarawak, involving 173 randomly selected respondents among manufacturing factory workers. Data collected were respondents' workplace monitoring data and their audiometry records obtained from the factory record, and the otoscopy examinations performed. In addition, respondents were required to fill up an interviewer-guided questionnaire. RESULTS: The prevalence of NIHL was high (49.7%). The factors which were found to have a significant association with NIHL in bivariate analysis were age (p < 0.05, 95% CI), male gender (p < 0.05; OR - 7.60; CI 3.34 -18.38), duration of employment (p <0.05), knowledge of noise level (p < 0.05; OR - 4.11; CI 1.10 - 15.28), working at polishing department (p < 0.05; OR - 4.23; CI 2.13 - 8.43), and smoking (p < 0.05; OR - 39.6; CI 16.5 - 94.8). Pack-years of smoking were also found to have a significant association with p < 0.05. However, only smoking was statistically significant in multivariate analysis, where the risk of developing NIHL was 27.55 (p < 0.005; CI 10.74 - 70.64) among smokers. CONCLUSION: The high prevalence of NIHL despite the existing Hearing Conservation Program (HCP) may indicate that there may be some elements in HCP that require close monitoring by the factory management, and the importance of smoking cessation among the workers exposed to noise at the workplace should be highlighted.

Risk factors associated with occupational noise-induced hearing loss in the Hispanic community health study/study of Latinos: A cross-sectional epidemiologic investigation.

The purpose of this study was to estimate the prevalence of occupational noise exposure and risk factors of occupational noise-induced hearing loss (NIHL) in Hispanic/Latino adults included in the baseline wave of the Hispanic Community Health Study/Study of Latinos collected from 2008 to 2011. Sequential multiple linear regression modeled the relationship between occupational NIHL (defined as a 3-, 4-, 6-kHz pure-tone average [PTA]) and occupation type, self-reported noise exposure, cardiovascular disease (CVD) risk score, and hearing protective device (HPD) use. The final model controlled for sex, age, and recreational noise exposure. Among 12,851 included participants, approximately 40% (n = 5036) reported occupational noise exposure "Sometimes" (up to 50% of the time) or "Frequently" (75-100% of the time). In the final fitted model, longest-held occupation and CVD risk were associated with poorer hearing. Specifically, those in non-skilled, service, skilled, and military/police/other job categories had between 2.07- and 3.29-dB worse PTA than professional/office workers. Additionally, a shift in the CVD risk score category from low to medium was associated with a 2.25- and 8.20-dB worse PTA for medium and high CVD risk, respectively. Age and sex were also significantly associated with poorer hearing, such that men presented with 6.08 dB worse PTA than women, and for every one-year increase in age, PTA increased by 0.62 dB (ps < .001). No interactions were seen between noise*sometimes or frequent exposure to other ototoxic agents and PTA (ps = .33 & .92, respectively). The prevalence of occupational noise exposure was high in this cross-sectional investigation of adults from Hispanic/Latino backgrounds. Findings contribute to the extant literature by demonstrating that risk factors for occupational NIHL in adults from varying Hispanic/Latino backgrounds are consistent with those of other previously studied groups.

The role of kurtosis and kurtosis-adjusted energy metric in occupational noise-induced hearing loss among metal manufacturing workers.

Background: Noise energy has been well-established to increase the risk of occupational noise-induced hearing loss (NIHL). However, the role of noise temporal structure (expressed by kurtosis) or its combination with energy metrics (e.g., kurtosis-adjusted cumulative noise exposure, adj-CNE) in occupational NIHL was still unclear. Methods: A cross-sectional survey of 867 Chinese workers, including 678 metal manufacturing workers and 189 workers exposed to Gaussian noise, was conducted. Noise energy metrics, including LAeq,8h and CNE, kurtosis (ß), and adj-CNE were used to quantify noise exposure levels. Noise-induced permanent threshold shift at frequencies 3, 4, and 6 kHz (NIPTS346) and the prevalence of high-frequency NIHL (HFNIHL%) were calculated for each participant. The dose-response relationship between kurtosis or adj-CNE and occupational NIHL was observed. Results: Among 867 workers, different types of work had specific and independent noise energy and kurtosis values (p > 0.05). HFNIHL% increased with an increase in exposure duration (ED), LAeq,8h, CNE, or kurtosis (p < 0.01), and there were strong linear relationships between HFNIHL% and ED (coefficient of determination [R2] = 0.963), CNE (R2 = 0.976), or kurtosis (R2 = 0.938, when CNE < 100 dB(A)∙year). The "V" shape notching extent in NIPTS became deeper with increasing kurtosis when CNE < 100 dB(A)∙year and reached the notching bottom at the frequency of 4 or 6 kHz. The workers exposed to complex noise (ß ≥ 10) had a higher risk of NIHL than those exposed to Gaussian noise (ß < 10) at the frequencies of 3, 4, 6, and 8 kHz (OR > 2, p < 0.01). Moreover, HFNIHL% increased with adj-CNE (p < 0.001). There were strong linear relationships between NIHL and adj-CNE or CNE when ß ≥ 10 (R2adj-CNE > R2CNE). After CNE was adjusted by kurtosis, average differences in NIPTS346 or HFNIHL% between the complex and Gaussian noise group were significantly reduced (p < 0.05). Conclusion: Kurtosis was a key factor influencing occupational NIHL among metal manufacturing workers, and its combination with energy metrics could assess the risk of NIHL more effectively than CNE alone.

Hearing loss and respiratory health symptoms among large-scale sawmill workers of the timber processing factories within the Gert Sibande District Municipality: a comparative cross-sectional study.

BACKGROUND: Occupational exposure to wood dust may cause respiratory illnesses, while prolonged exposure to loud noise may cause noise-induced hearing loss. OBJECTIVE: The objective of the study was to assess the prevalence of hearing loss and respiratory symptoms among large-scale sawmill workers within the Gert Sibande Municipality in Mpumalanga Province, South Africa. METHODS: A comparative cross-sectional study consisting of 137 exposed and 20 unexposed randomly selected workers was undertaken from January to March 2021. The respondents completed a semi-structured questionnaire on hearing loss and respiratory health symptoms. DATA ANALYSE: The data was analysed using Statistical Package for Social Sciences (SPSS) version 21 (Chicago II, USA). The statistical analysis of the difference between the two proportions was done using an independent student t-test. The level of significance was set at p < 0.05. RESULTS: There was a statistically significant difference between the exposed and unexposed workers on the prevalence of respiratory symptoms like phlegm (51.8 vs. 0.0%) and shortness of breath (chest pain) (48.2 vs. 50%). There was also a statistically significant difference between the exposed and unexposed workers on the signs and symptoms of hearing loss like tinnitus (ringing in the ears) (50 vs. 33.3%), ear infections (21.4 vs. 66.7%), ruptured ear drums (16.7 vs. 0.0%), and ear injuries (11.9 vs. 0.0%). The exposed workers reported always wearing personal protective equipment (PPE) (86.9%) compared to the unexposed workers (75%). The reason for not wearing PPE consistently by the exposed workers was due to not being available (48.5%), compared to the unexposed workers who reported other reasons (100%). CONCLUSION: The prevalence of respiratory symptoms among the exposed workers was higher than that of the unexposed workers, except for chest pains (shortness of breath). The prevalence of symptoms of hearing loss among the exposed workers was higher than the unexposed workers, except for ear infections. The results suggest that measures should be implemented at the sawmill to help protect workers' health.