Prevalence of hearing loss in the United States by industry

Prevalence of Hearing Loss Among Noise-Exposed US Workers Within the Utilities Sector, 2010-2019

OBJECTIVE

This study's objective was to estimate hearing loss prevalence for noise-exposed US Utilities workers.

METHODS

In this cross-sectional study of a retrospective cohort, audiograms were examined for 1.3 million workers (13,595 within utilities) from 2010-2019. Hearing loss prevalence and adjusted risk as compared with a reference industry were estimated.

RESULTS

The hearing loss prevalence for noise-exposed Utilities workers (25%) was higher than for noise-exposed workers in all industries combined (20%). Some subsectors surpassed the prevalence for all industries combined and/or had adjusted risks significantly higher than the reference industry. The highest prevalence subsectors were Hydroelectric Power Generation (37%) and steam and Air-Conditioning Supply (29%).

CONCLUSIONS

While often overlooked, noise-exposed workers in this sector have among the highest prevalences of hearing loss and significantly higher risks. Increased attention and better hearing conservation strategies are needed.

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.

Prevalence and Associated Factors of Sensorineural Hearing Impairment Among Patients with T2DM in Amhara Region, Northwest Ethiopia, 2022: A Multi-Centered Cross-Sectional Study

Background

Generally, people with type 2 diabetes mellitus in various countries experience a significant rate of sensorineural hearing impairment. Nonetheless, there is scant evidence of sensorineural hearing impairment among type 2 diabetes mellitus patients in Northwest Ethiopian. Therefore, the objective of this study was to evaluate the occurrence rate and contributing factors of sensorineural hearing impairment in type 2 diabetics at comprehensive and specialized referral hospitals in Northwest Ethiopia.

Methods

A facility-based cross-sectional study design was carried out from May 3, 2022, to June 14, 2022, on 846 study participants in Ethiopia, with a response rate of 99.65%. The research subjects were chosen by simple random sampling techniques. Data was gathered by using audiometric measurements and structured interview-administered questionnaires and then entered into EPI data version 4.6. Finally, it was exported to STATA 14 for analysis. Binary logistic regression, chi-square test, and odds ratio were done to verify the assumptions and degree of association. Ultimately, factors exhibiting a p-value < 0.05 with a 95% CI were regarded as significant predictors of hearing impairment.

Results

The magnitude of sensorineural hearing impairment in this investigation was 50.49% (95% CI: 45.67%, 55.26%). Factors significantly associated with sensorineural hearing impairment were age (AOR=1.10, 95% CI: 1.07, 1.14), hyperlipidemia (AOR=2.86, 95% CI: 1.05, 7.82), duration of diabetes (AOR=2.26, 95% CI: 1.26, 4.06), hypertension (AOR=1.94, 95% CI: 1.02, 3.69) and regular physical exercise (AOR=0.25, 95% CI: 0.09, 0.68).

Conclusions and Recommendations

In this study, relatively high rates of sensorineural hearing impairment were observed. Stakeholders should establish routine hearing screening, and participants will advise to incorporate regular physical exercise into their routines.

Workers' Compensation Costs for Occupational Hearing Loss Claims in the United States, 2009-2013

This study estimated the average annual number of U.S. workers' compensation (WC) claims for occupational hearing loss (OHL) and their associated cost and identified the industry/occupation classifications with the highest numbers of OHL claims. The most recent U.S. cost estimate ($242 million) was based on data from one state in 1 year (1991). WC data from the National Council on Compensation Insurance, Inc. (35 states) and two additional individual states were examined, incorporating data from 37 states and the District of Columbia. Costs and numbers of claims were estimated for the 13 missing states to develop estimates for the United States. Sensitivity analyses were also performed to develop ranges for the point estimates. The estimated U.S. average annual OHL claim cost fell within the range of $49 to $67 million during 2009-2013, with a point estimate of $60 million (2013 dollars). The estimated average annual number of OHL claims ranged from 4,114 to 5,986, with a point estimate of 4,965 claims. Based on data available from 36 states and DC, 18 of the 40 industry/occupation classifications with ≥50 OHL claims were in the manufacturing sector. WC data underestimate the true burden of OHL. Most OHL cases are not compensated. WC laws, industry composition and other factors vary widely by state, so estimates must employ data for many states. This study incorporated data from most states and utilized sensitivity and comparative analyses to obtain estimates. Workers in a wide range of industry/occupation classifications need special attention to prevent OHL.

Preventing Occupational Hearing Loss: 50 Years of Research and Recommendations from the National Institute for Occupational Safety and Health

For more than 50 years, the National Institute for Occupational Safety and Health (NIOSH), part of the United States (U.S.) Centers for Disease Control and Prevention (CDC), has been actively working to reduce the effects of noise and ototoxic chemicals on worker hearing. NIOSH has pioneered basic and applied research on occupational hearing risks and preventive measures. The Institute has issued recommendations and promoted effective interventions through mechanisms ranging from formal criteria documents to blogs and social media. NIOSH has conducted surveillance and published statistics to guide policy and target prevention efforts. Over the past five decades, substantial progress has been made in raising awareness of noise as a hazard, reducing the risk of occupational hearing loss, improving the use of hearing protection, and advancing measurement and control technologies. Nevertheless, noise remains a prevalent workplace hazard and occupational hearing loss is still one of the most common work-related conditions. NIOSH continues to work toward preventing the effects of noise and ototoxicants at work and has many resources to assist audiologists in their hearing loss prevention efforts.

Noise Exposure and Hearing Loss among Workers at a Hammer Forge Company

The National Institute for Occupational Safety and Health (NIOSH) evaluated continuous and impact noise exposures and hearing loss among workers at a hammer forge company. Full-shift personal noise exposure measurements were collected on forge workers across 15 different job titles; impact noise characteristics and one-third octave band noise levels were assessed at the forge hammers; and 4,750 historic audiometric test records for 483 workers were evaluated for hearing loss trends. Nearly all workers' noise exposures exceeded regulatory and/or recommended exposure limits. Workers working in jobs at or near the hammers had full-shift time-weighted average noise exposures above 100 decibels, A-weighted. Impact noise at the hammers reached up to 148 decibels. Analysis of audiometric test records showed that 82% of workers had experienced a significant threshold shift, as defined by NIOSH, and 63% had experienced a standard threshold shift, as defined by the Occupational Safety and Health Administration (OSHA). All workers with an OSHA standard threshold shift had a preceding NIOSH significant threshold shift which occurred, on average, about 7 years prior. This evaluation highlights forge workers' exposures to high levels of noise, including impact noise, and how their hearing worsened with age and length of employment.

Evaluating the potential impact of ototoxicant exposure on worker health

Occupational exposure to ototoxicants, substances that can cause hearing loss alone or exacerbate hearing loss when exposure occurs in combination with noise, is a workplace hazard that is poorly understood. A review of existing research indicates that some solvents and heavy metals may be ototoxic, but few studies have attempted to estimate the impact of ototoxicant exposure on the United States worker population. Researchers examined trends in workplace exposure to ototoxicants among workers in the United States by comparing exposure data collected by the Occupational Safety and Health Administration against worker hearing loss data provided by the Bureau of Labor Statistics (BLS) for 2012-2019. The study found that the noise exposure data was strongly correlated to the hearing loss data using Pearson's correlation (p < .001), confirming that the exposure data collected by OSHA is predictive of the risk of occupational illness as reported by BLS. Chi-square analysis indicates that reported hearing loss was more common among industry subsectors with exposure to ototoxicants than those without exposure to ototoxicants. These findings suggest that workers with coexposure to ototoxicants and noise may be at a higher risk of experiencing hearing loss than those exposed to noise alone, and action should be taken to minimize this risk.

NIOSH Hearing Loss Prevention Program for Mining

Noise-induced hearing loss (NIHL) continues to be a pervasive problem for the nation's workforce, particularly the nation's mining personnel. As one of the leading health and safety organizations in the world, the National Institute for Occupational Health and Safety (NIOSH) in Pittsburgh maintains a Hearing Loss Prevention Program (HLPP) to conduct research to reduce NIHL loss among the nation's miners. This document provides a brief overview of this HLPP, describing some of the research techniques involved in the development of engineering noise controls, methods for the development of administrative noise controls, and some of the products available to the public to protect the nation's workers hearing.

Age-related hearing loss and its potential drug candidates: a systematic review

BACKGROUND

Age-related hearing loss (ARHL) is one of the main illnesses afflicting the aged population and has a significant negative impact on society, economy, and health. However, there is presently no appropriate therapeutic treatment of ARHL due to the absence of comprehensive trials.

OBJECTIVES

The goal of this review is to systematically evaluate and analyze recent statistics on the pathologic classifications, risk factors, treatment strategies, and drug candidates of ARHL, including that from traditional Chinese medicine (TCM), to provide potential new approaches for preventing and treating ARHL.

METHODS

Literature related to ARHL was conducted in databases such as PubMed, WOS, China National Knowledge Infrastructure (CNKI), and Wanfang from the establishment of the database to Jan, 2023. The pathology, causal factor, pathophysiological mechanism, treatment strategy, and the drug candidate of ARHL were extracted and pooled for synthesis.

RESULTS

Many hypotheses about the etiology of ARHL are based on genetic and environmental elements. Most of the current research on the pathology of ARHL focuses on oxidative damage, mitochondrial dysfunction, inflammation, cochlear blood flow, ion homeostasis, etc. In TCM, herbs belonging to the kidney, lung, and liver meridians exhibit good hearing protection. Seven herbs belonging to the kidney meridian, 9 belonging to the lung meridian, and 4 belonging to the liver meridian were ultimately retrieved in this review, such as Polygonum multiflorum Thunb., Panax ginseng C.A. Mey, and Pueraria lobata (Willd.) Ohwi. Their active compounds, 2,3,4',5-Tetrahydroxystilbene-2-O-D-glucoside, ginsenoside Rb1, and puerarin, may act as the molecular substance for their anti-ARHL efficacy, and show anti-oxidative, neuroprotective, anti-inflammatory, anti-apoptotic, or mitochondrial protective effects.

CONCLUSION

Anti-oxidants, modulators of mitochondrial function, anti-inflammation agents, vasodilators, K+ channel openers, Ca2+ channel blockers, JNK inhibitors, and nerve growth factors/neurotrophic factors all contribute to hearing protection, and herbs are an important source of potential anti-ARHL drugs.

Risk perception or hazard perception? Examining misperceptions of miners' personal exposures to noise

While perceptions of risk have been examined in the workplace to understand safety behavior, hazard perception has been overlooked, particularly for chemical, physical, and biological agents. This study sought to establish the prevalence of one type of mismatch in hazard perception, - noise misperception - among miners, to examine whether different types of noisy environments (e.g., continuous, highly variable, etc.) alter workers' misperception of their noise exposures, and to evaluate whether noise misperception is associated with hearing protection device (HPD) use behavior. In this cross-sectional study across 10 surface mines in the USA, 135 normal-hearing participants were surveyed on their perceptions of exposure to noise at work and were monitored for three shifts, each with personal noise dosimetry, to examine which workers had a mismatch in perceived versus true noise exposure by 8-hr, time-weighted average, NIOSH exposure limits (TWANIOSH). Mixed effects logistic regression and probit Bayesian Kernel Machine Regression (BKMR) models examining on the odds of noise misperception associated with four different noise metrics (kurtosis, crest factor, variability, and number of peaks >135 dB) were used to determine which types of noisy environments may influence noise misperception. The relationship between noise misperception and odds of not wearing HPDs during a work shift was further examined. Our findings showed that nearly 1 in 3 workers underestimated their exposure to noise when their true exposure was in fact hazardous (TWANIOSH≥85 dBA) for at least one shift, and 6% misperceived hazardous exposures for all shifts. Work shifts with highly kurtotic noise distributions (>3) had 3.1 (95% CI: 1.1 to 8.4) times significantly higher odds of resulting in misperceived noise; no other noise metric was significantly associated with noise misperception. BKMR modeling provided further evidence that kurtosis dominates this relationship, with an IQR increase in kurtosis significantly associated with 1.68 (95% CI: 1.13 to 2.50) higher odds of noise misperception. Although not statistically significant, misperception of hazardous noise exposure was associated with 3.2 (95% CI: 0.8 to 12.5) times higher odds of not using earplugs during a work shift. Misperception of noise occurs in the workplace, and likely occurs for other physical, chemical, and biological exposures. This hazard misperception may influence risk perceptions and worker behavior and reduce the effectiveness of behavior-related training. Elimination, substitution, or engineering controls of exposures is the best way to prevent hazard misperceptions and exposure-related diseases.

Health conditions among male workers in mining and other industries reliant on manual labor occupations: National Health Interview Survey, 2007-2018

INTRODUCTION

Mining is an industry with diverse, demanding occupational exposures. Understanding the prevalence of chronic health conditions in working miners is an area of active research. Of particular interest is how the health of miners compares to that of workers in other industry sectors with a high proportion of manual labor occupations. By comparing similar industries, we can learn what health conditions may be associated with manual labor and with individual industries. This study analyzes the prevalence of health conditions in miners compared to workers employed in other manual-labor-reliant industries.

METHODS

National Health Interview Survey public data were analyzed for the years 2007-2018. Mining and five other industry groups with a high proportion of manual labor occupations were identified. Female workers were excluded because of small sample sizes. The prevalence of chronic health outcomes was calculated for each industry group and compared to that of nonmanual labor industries.

RESULTS

Currently-working male miners showed increased prevalence of hypertension (in those age <55 years), hearing loss, lower back pain, leg pain progressing from lower back pain, and joint pain, compared to nonmanual labor industries workers. Construction workers also demonstrated a high prevalence of pain.

CONCLUSION

Miners demonstrated increased prevalence of several health conditions, even when compared to other manual labor industries. Given previous research on chronic pain and opioid misuse, the high pain prevalence found among miners suggests mining employers should reduce work factors that cause injury while also providing an environment where workers can address pain management and substance use.

Music as a unique source of noise-induced hearing loss

Music is among the most important artistic, cultural, and entertainment modalities in any society. With the proliferation of music genres and the technological advances that allow people to consume music in any location and at any time, music over-exposure has become a significant public health issue. Music-induced hearing loss has a great deal in common with noise-induced hearing loss. However, there are important differences that make music a unique insult to the auditory system and a unique threat to public health. Its unique properties also make it a potentially valuable asset in sound conditioning paradigms. This review discusses hearing loss from noise and music, comparing and contrasting the two. Recent research on music-induced hearing loss is reviewed, followed by discussion of the differences in music-induced hearing loss between performers and consumers. The review concludes with a discussion of the potential of music as a sound conditioning stimulus to protect against acquired hearing loss.

Noise exposure assessment of non-coal mining workers in four provinces of China

Objective

This study aimed to understand the noise exposure of non-coal mines in China to take appropriate controls to protect workers' health.

Methods

An assessment of non-coal miners' noise exposures was conducted in four provinces in China. Individual noise exposure levels were measured, and the survey on the hearing protector device (HPD) equipment was administered.

Results

423 noise dosimeter measurements were obtained, including drilling, blasting, ore drawing, transportation, winching, crushing, screening and ball milling, and auxiliary (air pressure, pump, and maintenance). A total of 31.9% of the individual noise levels (L_EX,8h) exceeded 85 dB(A), and the median dosages of non-coal miners with high noise exposure were: excavation workers-89.1 dB(A), mill operators-88.7 dB(A), and crusher operators-87.0 dB(A). The noise dose of underground mine workers is higher than that of surface mine workers (P < 0.001). A total of 53.7% of non-coal mining enterprises are not equipped with HPD for workers, mainly small and micro enterprises.

Conclusions

High levels of hazardous noise exposure are typical in non-coal mines. Noise exposure data can help to develop more feasible noise controls.

Sex-Linked Biology and Gender-Related Research Is Essential to Advancing Hearing Health

There is robust evidence that sex (biological) and gender (behavioral/social) differences influence hearing loss risk and outcomes. These differences are noted for animals and humans-in the occurrence of hearing loss, hearing loss progression, and response to interventions. Nevertheless, many studies have not reported or disaggregated data by sex or gender. This article describes the influence of sex-linked biology (specifically sex-linked hormones) and gender on hearing and hearing interventions, including the role of sex-linked biology and gender in modifying the association between risk factors and hearing loss, and the effects of hearing loss on quality of life and functioning. Most prevalence studies indicate that hearing loss begins earlier and is more common and severe among men than women. Intrinsic sex-linked biological differences in the auditory system may account, in part, for the predominance of hearing loss in males. Sex- and gender-related differences in the effects of noise exposure or cardiovascular disease on the auditory system may help explain some of these differences in the prevalence of hearing loss. Further still, differences in hearing aid use and uptake, and the effects of hearing loss on health may also vary by sex and gender. Recognizing that sex-linked biology and gender are key determinants of hearing health, the present review concludes by emphasizing the importance of a well-developed research platform that proactively measures and assesses sex- and gender-related differences in hearing, including in understudied populations. Such research focus is necessary to advance the field of hearing science and benefit all members of society.

Awareness, Use, and Opinions of Individual Fit Testing of Hearing Protection Devices Among Practicing Michigan Occupational and Environmental Medicine Association Health Care Providers

OBJECTIVE

The aim of this study is to examine the awareness, opinions, and use of individual fit testing of hearing protection devices (HPDs) among occupational medicine practitioners.

METHODS

Members of the Michigan Occupational and Environmental Medicine Association completed a 21-question survey on individual fit testing of HPDs.

RESULTS

The survey response rate was 67%, 53% reported having heard of individual fit testing of HPDs, and 24% reported that their clinic/site performed the testing. Major barriers to its use were perceived time to perform (63%), cost (51%), lack of an Occupational Safety and Health Administration requirement (51%), and lack of long-term studies of its effectiveness (20%).

CONCLUSIONS

Further work to educate practitioners about the availability, implementation, and potential benefits of fit testing of HPDs is needed if use of this technology is to become more widespread.

How much have adverse occupational health outcomes among construction workers improved over time? Evidence from 25 years of medical screening

BACKGROUND

Construction workers have always had a high risk of occupational illnesses. We used 25 years of data from a medical screening program serving older construction workers to determine how much health outcomes have improved over the past 60 years.

METHODS

We investigated changes in relative risk for chest radiographs consistent with pneumoconiosis, COPD by spirometry, lung cancer mortality, and audiometry-assessed hearing impairment among workers participating in a medical screening program. Results were stratified by decade of first construction employment: before 1960, 1960-1969, 1970-1979, 1980-1989, and after 1990. Poisson and Cox regression analyses assessed relative risk by decade adjusted for age, sex, smoking, and years of construction trade work.

RESULTS

Subjects were 94% male and, on average, 60 years old with 25 years of construction work. When compared to workers employed before 1960, those first employed after 1990 experienced the following reductions in model-adjusted relative risks: chronic obstructive pulmonary disease, 32%; all pneumoconiosis, 68%; parenchymal abnormalities, 35%; pleural abnormalities, 71%; hearing impairment, 20%; and lung cancer mortality, 48%. Risks started to decline in the 1960s with greatest reductions among workers first employed after 1970.

CONCLUSIONS

This study demonstrates the positive impact that adoption of occupational health protections have had over the past 60 years. The greatest risk reductions were observed for outcomes with strong regulatory and legal incentives to reduce exposures and associated risks, such as those associated with inhalation hazards (asbestos and silica), while lowest improvement was for hearing impairment, for which little regulatory enforcement and few prevention incentives have been adopted.

Evaluation of human error in workers of an Iranian copper mine during the COVID-19 pandemic using the CREAM

BACKGROUND

The outbreak of COVID-19 has adversely affected both global economy and public health around the world. These effects have also been observed in many workplaces, including mines.

OBJECTIVE

This study aimed to examine the human error of copper miners during the pandemic.

METHOD

This descriptive-analytical, cross-sectional study was performed on 192 workers of a copper mine in Iran. For this, occupation tasks were firstly analyzed using the Hierarchical Task Analysis (HTA), and then the human error in different subunits was assessed using the basic Cognitive Reliability and Error Analysis Method (CREAM). The prevalence of COVID-19 among miners was determined by assessing positive PCR test records.

RESULTS

The probability of human error in the operational subunits including mining, crushing, processing, and support subunits was estimated to be 0.0056, 0.056, 0.0315, and 0.0177, respectively. All three operational units were found to be in the scrambling control mode. The support unit was determined to be in the tactical control mode. Approximately 50% of all workers had been infected with COVID-19, with the highest prevalence in support units.

CONCLUSION

The results suggest that during the COVID-19 pandemic, copper miners are at higher risk of human error induced by poor working conditions. Therefore, it is recommended to employ some management strategies such as promotion of safety, health monitoring, and adopting supportive measures to control occupational stresses and therefore the probability of human error in the mine's operational units.

Evaluating Occupational Noise Exposure as a Contributor to Injury Risk among Miners

OBJECTIVES

This study: (i) assessed the relationship between noise exposure and injury risk, comprehensively adjusting for individual factors, psychosocial stressors, and organizational influences; (ii) determined the relative importance of noise on injuries; (iii) estimated the lowest observed adverse effect level (LOAEL) of noise on injury risk to determine the threshold of noise considered hazardous to injuries; and (iv) quantified the fraction of injuries that could be attributed to hazardous noise exposure.

METHODS

In this cross-sectional study at 10 US surface mine sites, traditional mixed effects, Poisson regression, and boosted regression tree (BRT) models were run on the number of reported work-related injuries in the last year. The LOAEL of noise on injuries was identified by estimating the percent increase in work-related injuries at different thresholds of noise exposure using a counterfactual estimator through the BRT model. A population attributable fraction (PAF) was quantified with this counterfactual estimator to predict reductions in injuries at the LOAEL.

RESULTS

Among 18 predictors of work-related injuries, mine site, perceived job safety, age, and sleepiness were the most important predictors. Occupational noise exposure was the seventh most important predictor. The LOAEL of noise for work-related injuries was a full-shift exposure of 88 dBA. Exposure ≥88 dBA was attributed to 20.3% (95% CI: 11.2%, 29.3%) of reported work-related injuries in the last year among the participants.

CONCLUSIONS

This study further supports hypotheses of a dose-response relationship between occupational noise exposure and work-related injuries, and suggests that exposures ≥88 dBA may increase injury risk in mining.

Hearing Function and Nutritional Status in Aviation Pilots from Spain Exposed to High Acoustic Damage

Noise-induced hearing loss is the most frequent and preventable occupational disease. Aviation pilots are a vulnerable population, as they spend many hours exposed to noise pollution in their working environment. Different studies suggest that certain dietary compounds may play a key role in the etiology and prevention of this pathology. We aimed to study the relationship linking auditory function, dietary intake, and some serum biomarkers in pilots, exposed to noise in the work environment. A total of 235 pilots, who undergo a periodic medical examination at the Centro de Instrucción de Medicina Aeroespacial (Madrid, SPAIN), were evaluated. Auditory function was assessed by tonal audiometry. Energy and nutrient intakes were estimated by 24 h recall (DIALTM program). Serum homocysteine (Hcy) was determined in a Cobas 6000TM multi-analyzer while folate, vitamin B12, and D were analyzed in a Cobas e411TM. The prevalence of hearing loss (HL) was 64.3%. HL was significantly related to age (r = 0.588, p ≤ 0.001) and flight hours (r = 0.283, p ≤ 0.001). A multiple linear regression model was used to assess the relationship among HL, flight hours, serum folate, and Hcy serum levels. HL was significantly (p < 0.050) associated with flight hours (β = 0.246), serum folate (β = −0.143), and serum Hcy (β = 0.227). Nutritional interventions would be of great interest to monitor and slow down the HL progression in populations exposed to noise pollution in their workplace.

Pre-employment hearing threshold levels of 59,601 Australian male coal miners compared to an otologically normal international male population (ISO7029:2019)

OBJECTIVE

This study compared the pre-employment median hearing threshold level (HTL) distribution from a population of coal miners from New South Wales (NSW), Australia, to an otologically normal, age-matched population described by the International Standards Organisation (ISO) ISO 7029:2019, to determine any differences.

DESIGN

This was an observational, retrospective, repeated cross-sectional study.

STUDY SAMPLE

De-identified audiometric records of 59,601 male employees entering NSW coal mining in three representative five-year periods between 1991 and 2015 were utilised.

RESULTS

The median HTL deviation of the mining population was statistically significantly different (p < 0.05) from the ISO population, for almost all analyses. Overall, the mining population cohorts have higher (worse) median HTLs compared to the ISO population. The greatest difference occurs at 4 kHz in older age groups, likely indicating noise-induced hearing loss.

CONCLUSION

These findings indicate that some NSW coal mine workers commence their careers with evidence of pre-existing hearing loss (HL), in an industry with excessive noise exposures. These results provide Australian mining and other noisy industries with evidence to support a review of hearing conservation strategies to improve mitigation of hearing loss across the working lifespan.

Hearing impairment and tinnitus among older construction workers employed at DOE facilities

BACKGROUND

Few studies have defined the risk of hearing impairment and tinnitus after retirement. This report measures hearing impairment and tinnitus prevalence among older construction trades workers.

METHODS

The study cohort included 21,340 participants in a national medical screening program (www.btmed.org). Audiometric hearing impairment was classified according to the Global Burden of Disease Study. Tinnitus was determined by self-report. An internal subcohort of nonconstruction trades workers served as a reference group. Stratified analyses and multivariate analyses were used to measure the prevalence of hearing impairment and tinnitus by age, sex, and job category.

RESULTS

Prevalence of any hearing impairment was 55.2% (males, 57.7%; females, 26.8%) and increased rapidly with age. Construction trades workers were 40% more likely to have hearing impairment than the reference group. The overall prevalence of tinnitus was 46.52% and followed patterns similar to hearing impairment. Workers with hearing impairment were more likely to also have tinnitus, but tinnitus was frequently reported in the absence of measured hearing impairment.

CONCLUSIONS

Hearing impairment and tinnitus prevalence were much higher in this study than in previous research. A significant reason for the difference is that BTMed follows participants after they have retired. To draw conclusions about the risk for work-related chronic diseases and disorders it is important to monitor workers through their lifetimes. Also, tinnitus by itself should be given greater significance. These findings reinforce the need to promote noise reduction and hearing conservation in construction.

Medical Therapy of Hearing Impairment and Tinnitus with Chinese Medicine: An Overview

The current review gives a comprehensive overview of the recent development in Chinese medicine (CM) for treating several kinds of acquired nerve deafness and tinnitus, as well as links the traditional principle to well-established pharmacological mechanisms for future research. To date, about 24 herbal species and 40 related ingredients used in CM to treat hearing loss and tinnitus are reported for the treatment of endocochlear potential, endolymph growth, lowering toxic and provocative substance aggregation, inhibiting sensory cell death, and retaining sensory transfer. However, there are a few herbal species that can be used for medicinal purposes. Nevertheless, clinical studies have been hampered by a limited population sample, a deficiency of a suitable control research group, or contradictory results. Enhanced cochlear blood flow, antiinflammatory antioxidant, neuroprotective effects, and anti-apoptotic, as well as multi-target approach on different auditory sections of the inner ear, are all possible benefits of CM medications. There are numerous unknown natural products for aural ailment and tinnitus identified in CM that are expected to be examined in the future utilizing various aural ailment models and processes.

Metabolic and Sensory Components of Age-Related Hearing Loss

Age-related hearing loss is a multifactorial condition with effects of aging and environmental exposures that contribute to cochlear pathologies. Metabolic hearing loss involves declines in the endocochlear potential, which broadly reduce cochlear amplification of low-level sounds. Sensory hearing loss involves damage to outer hair cells that may eliminate amplification, especially for high-frequency sounds. A novel approach was developed to estimate the extent of metabolic and sensory components (in dB) for an individual, by combining hearing loss profiles to optimally approximate their hearing thresholds (audiogram). This approach was validated using estimates of metabolic and sensory hearing loss from retrospective datasets including gerbils, cross-sectional and longitudinal audiograms from older adults, a measure of speech recognition in noise, and histopathology case reports. Simulation results showed that well-approximated audiograms can produce accurate metabolic and sensory estimates. Estimates of metabolic and sensory components of age-related hearing loss differentiated gerbils with known strial and/or sensory pathologies based on age and exposures. For older adults, metabolic estimates consistently increased with age and were associated with poorer speech recognition in noise, while sensory estimates were related to sex and noise exposure differences. Histopathology case reports (with audiograms) that described strial and outer hair cell pathology in temporal bones from older donors showed significant differences in metabolic and sensory estimates, respectively. The results support the view that audiograms include information that can be used to estimate the metabolic and sensory components of age-related hearing loss.

Self Reported Hearing Impairments and Associated Risk Factors Among Metal and Woodwork Workers in Gondar Town, North West Ethiopia

BACKGROUND

The global prevalence of occupational noise-induced hearing loss ranges between 16% and 24%. The wood and metalwork industries have recently expanded in Ethiopia. This study aims to determine the level of noise exposure and the prevalence of self-reported hearing impairments and associated risk factors among metal and woodworkers in Gondar town Ethiopia.

MATERIAL AND METHODS

An institutional-based cross-sectional study was conducted on 580 metal and woodwork workers from February10 to March 25/2020. The data were collected through an interviewer-led questioner and the noise level measurement. Multivariate Poisson regression models were used. P-values less than .05 and adjusted prevalence ratios with 95%CI were used to declare the presence and strength of an association respectively.

RESULT

The mean (SD) average noise exposure level in the wood and metalworking industries was 96.9 ± 3.5 dBA and 96.2 ± 4 dBA, respectively. The overall prevalence of self-reported hearing impairment was 20.7% [95%CI: (17.4-24)]. In an adjusted Poisson regression, listening to music with earphones for more than 2 hours per day (PR = 2.95, 95%CI: 1.32, 6.21) and listening to music at maximum volume (PR = 2.24, 95%CI: 1.05, 4.79) were associated with hearing impairments.

CONCLUSION

The majority of workers are exposed to noise levels that exceed OSHA's permissible exposure limit value. A hearing conservation program should be implemented to reduce noise exposure levels in the wood and metal work industries. Workers should be aware of the duration and volume of recreational noise exposure.

Area Noise Assessment at Surface Stone, Sand, and Gravel Mines: Application for Reducing Worker Noise Exposure

Repeated noise exposure and occupational hearing loss are common health problems across industries and especially within the mining industry. Large mechanized processes, blasting, grinding, drilling, and work that is often in close quarters put many miners at an increased risk of noise overexposure. In stone, sand, and gravel mining, noise is generated from a variety of sources, depending on the type of ore being mined as well as the final consumer product provided by that mine. Depending on the source of noise generation, different strategies to reduce and avoid that noise should be implemented. The National Institute for Occupational Safety and Health (NIOSH) has evaluated the noise profile at three operational surface stone, sand, and gravel mines. A-weighted sound level meter data as well as phase array beamforming data were collected throughout the mines in areas with high noise exposure or high personnel foot or vehicle traffic. Sound level meter data collected on a grid pattern was used to develop sound profiles of the working areas. These sound contour maps as well as phase array beamforming plots were provided to the mines as well as guidance to modify work areas or personnel traffic to reduce noise exposure.

Retrospective assessment of the association between noise exposure and nonfatal and fatal injury rates among miners in the United States from 1983 to 2014

BACKGROUND

Mining is a significant economic force in the United States but has historically had among the highest nonfatal injury rates across all industries. Several factors, including workplace hazards and psychosocial stressors, may increase injury and fatality risk. Mining is one of the noisiest industries; however, the association between injury risk and noise exposure has not been evaluated in this industry. In this ecological study, we assessed the association between noise exposure and nonfatal and fatal occupational injury rates among miners.

METHODS

Federal US mining accident, injury, and illness data sets from 1983 to 2014 were combined with federal quarterly mining employment and production reports to quantify annual industry rates of nonfatal injuries and fatalities. An existing job-exposure matrix for occupational noise was used to estimate annual industry time-weighted average (TWA, dBA) exposures. Negative binomial models were used to assess relationships between noise, hearing conservation program (HCP) regulation changes in 2000, year, and mine type with incidence rates of injuries and fatalities.

RESULTS

Noise, HCP regulation changes, and mine type were each independently associated with nonfatal injuries and fatalities. In multivariate analysis, each doubling (5 dB increase) of TWA was associated with 1.08 (95% confidence interval: 1.05, 1.11) and 1.48 (1.23, 1.78) times higher rate of nonfatal injuries and fatalities, respectively. HCP regulation changes were associated with 0.61 (0.54, 0.70) and 0.49 (0.34, 0.71) times lower nonfatal injury and fatality rates, respectively.

CONCLUSION

Noise may be a significant independent risk factor for injuries and fatalities in mining.

Trends in Hearing Protection Use With Occupational Noise Exposure in the United States 1999 to 2016

OBJECTIVE

Determine hearing protection use in relation to occupational noise exposure, tinnitus, and audiometry-measured hearing loss in the United States from 1999 to 2016.

STUDY DESIGN

Cross-sectional study utilizing US National Health and Nutritional Examination Survey (NHANES) 1999 to 2016 with occupation, reported occupational noise exposure, hearing protection use, tinnitus, and audiometry-measured hearing loss data. Subgroup analysis divided data into two cohorts early 2000s and 2010s.

SETTING

Population-based study using NHANES database capturing representative sample of US population.

PARTICIPANTS

Individuals with complete data 1999 to 2004 (n = 10,347) and 2011 to 2012 with 2015 to 2016 (n = 9,383).

INTERVENTIONS

Participants self-reported occupational noise exposure lasting more than 4 h/d for more than 3 months. Self-reported hearing protective device uses and tinnitus frequency. Audiometric hearing loss objectively measured.

MAIN OUTCOME MEASURES

Hearing protection use. Secondary measures included self-reported bothersome tinnitus and audiometrically measured hearing loss.

RESULTS

Across occupations, reported occupational noise exposure was higher in 2010s [32%, 95% CI: 29.6-34.6%] than 2000s [12.5%, 95% CI: 11.2-13.9%], while hearing protection use remained low in 2000s [41.3%, 95% CI: 37.8-44.8%] and 2010s [32.8%, 95% CI: 29.8-35.8%]. Less hearing protection use was associated with absence of bothersome tinnitus. Factors associated with increased hearing protection use were younger age, male sex, college education or higher, and white race in a multivariate model.

CONCLUSIONS

Reported occupational noise exposure appeared to increase from 2000s to 2010s yet hearing protection use remained stable at low use rate. As noise exposure is a major risk factor for hearing loss, significant education and reinforcement of appropriate hearing protection use for workplace noise exposures is necessary to preserve workers' hearing.

Prevalence of hearing protection device non-use among noise-exposed US workers in 2007 and 2014

BACKGROUND

This study estimated the prevalence of hearing protection device (HPD) non-use among US workers exposed to hazardous workplace noise and provided risk estimates.

METHODS

Self-reported data from the National Health Interview Survey in 2007 (15,852 workers) and 2014 (23,656 workers) were examined. Weighted prevalence and adjusted prevalence ratios of HPD non-use (using HPDs half the time or less when exposed to hazardous noise) were estimated by demographic, industry, and occupation. Differences in the prevalences of non-use were estimated and compared.

RESULTS

The prevalence of HPD non-use was 53% among all noise-exposed workers in 2014. Workers in the Accommodation and Food Services industry had the highest prevalence (90%) and risk (PR: 2.47, 95% confidence interval: 1.54-3.96) of HPD non-use. The industries with the lowest prevalences of noise exposure, including Finance and Insurance (2%) and Health Care and Social Assistance (4%), had some of the highest prevalences of HPD non-use (80% and 83%, respectively). There were no statistically significant changes in HPD non-use among industries between 2007 and 2014. Among occupations, HPD non-use increased 37% in Arts, Design, Entertainment, Sports and Media, and decreased 39% in Architecture and Engineering.

CONCLUSION

The prevalence of HPD non-use remains high; especially within industries and occupations with fewer noise-exposed workers. These groups need targeted attention to increase awareness and compliance. Employers should require HPD use and trainings among noise-exposed workers and provide an assortment of HPDs tailored to noise level and type, workplace environment, communication and audibility needs, and individual comfort and convenience.

Computational Audiology: New Approaches to Advance Hearing Health Care in the Digital Age

The global digital transformation enables computational audiology for advanced clinical applications that can reduce the global burden of hearing loss. In this article, we describe emerging hearing-related artificial intelligence applications and argue for their potential to improve access, precision, and efficiency of hearing health care services. Also, we raise awareness of risks that must be addressed to enable a safe digital transformation in audiology. We envision a future where computational audiology is implemented via interoperable systems using shared data and where health care providers adopt expanded roles within a network of distributed expertise. This effort should take place in a health care system where privacy, responsibility of each stakeholder, and patients' safety and autonomy are all guarded by design.

Hearing Impairment in Municipal Refuse and Glass Recycling Collection Operatives

Several international regulatory bodies and researchers have identified employees in the municipal refuse and recycling industry as potentially at risk of noise induced hearing loss. Whilst materials recycling facilities have been subject to research regarding the health effects of hazardous exposures, the roadside recycling collection aspects of the industry has been identified as requiring further investigation. The requirement for characterization of such risk has been increased in the European Union by legislation that has led to increased rates of municipal recycling in the waste disposal industry. In particular, the introduction of glass recycling collection rounds over recent years, alongside long-established refuse collection activities, has given rise to possible further increased levels of industrial noise exposure, beyond that of refuse collection alone. This cross-sectional study describes hearing threshold categorization in 201 male full-time refuse collection workers, most of whom had many years of employment in municipal refuse collection, and all of whom, in the 3-4 years preceding the study, had commenced a work pattern of alternating weeks of municipal glass recycling collection and refuse collection. During this period there was no compulsory use of personal hearing protective equipment. No excess of hearing loss was found in this group, irrespective of years in refuse collection duties or when compared with those studied with additional responsibilities as a driver of refuse wagons (a task not considered to lead to excessive noise exposure). Further research into hearing loss in such employees is merited, given the short time period of exposure to noise from glass collection, but the possible benefit of undertaking detailed full shift personal noise exposure in this group is proposed.

Dynamically Masked Audiograms With Machine Learning Audiometry

OBJECTIVES

When one ear of an individual can hear significantly better than the other ear, evaluating the worse ear with loud probe tones may require delivering masking noise to the better ear to prevent the probe tones from inadvertently being heard by the better ear. Current masking protocols are confusing, laborious, and time consuming. Adding a standardized masking protocol to an active machine learning audiogram procedure could potentially alleviate all of these drawbacks by dynamically adapting the masking as needed for each individual. The goal of this study is to determine the accuracy and efficiency of automated machine learning masking for obtaining true hearing thresholds.

DESIGN

Dynamically masked automated audiograms were collected for 29 participants between the ages of 21 and 83 (mean 43, SD 20) with a wide range of hearing abilities. Normal-hearing listeners were given unmasked and masked machine learning audiogram tests. Listeners with hearing loss were given a standard audiogram test by an audiologist, with masking stimuli added as clinically determined, followed by a masked machine learning audiogram test. The hearing thresholds estimated for each pair of techniques were compared at standard audiogram frequencies (i.e., 0.25, 0.5, 1, 2, 4, 8 kHz).

RESULTS

Masked and unmasked machine learning audiogram threshold estimates matched each other well in normal-hearing listeners, with a mean absolute difference between threshold estimates of 3.4 dB. Masked machine learning audiogram thresholds also matched well the thresholds determined by a conventional masking procedure, with a mean absolute difference between threshold estimates for listeners with low asymmetry and high asymmetry between the ears, respectively, of 4.9 and 2.6 dB. Notably, out of 6200 masked machine learning audiogram tone deliveries for this study, no instances of tones detected by the nontest ear were documented. The machine learning methods were also generally faster than the manual methods, and for some listeners, substantially so.

CONCLUSIONS

Dynamically masked audiograms achieve accurate true threshold estimates and reduce test time compared with current clinical masking procedures. Dynamic masking is a compelling alternative to the methods currently used to evaluate individuals with highly asymmetric hearing, yet can also be used effectively and efficiently for anyone.

Feasibility of a daily noise monitoring intervention for prevention of noise-induced hearing loss

BACKGROUND

Despite the existence of hearing conservation programmes complying with regulatory standards, noise-induced hearing loss (NIHL) remains one of the most prevalent occupational diseases. Compulsory daily monitoring of noise exposure has been associated with decreased NIHL risk. We report on the experience of a voluntary daily noise monitoring intervention among noise-exposed workers.

METHODS

Workers at three locations of a metals manufacturing company voluntarily used an in-ear noise monitoring device that could record and download, on a daily basis, the noise exposure inside of their hearing protection. We compared the hearing loss rates (in decibels hearing level/year) in these volunteers to controls from the same company matched for job title, age, gender, race, plant location, and baseline hearing level.

RESULTS

Over the follow-up period, 110 volunteers for whom controls could be identified monitored daily noise exposures an average of 150 times per year. Noise exposures inside of hearing protection were lower than ambient noise levels estimated from company records. While there was no significant difference in hearing loss rates between volunteers and controls, volunteers downloading exposures 150 times per year or had less hearing loss than those who downloaded less frequently.

CONCLUSION

These results indicate that voluntary daily noise exposure monitoring by workers is feasible and that greater frequency of downloading is associated with less hearing loss. If further development of noise monitoring technology can improve usability and address barriers to daily use, regular self-monitoring of noise exposure could improve the effectiveness of hearing conservation programmes.

TRIAL REGISTRATION NUMBER

NCT01714375.

Occupational Noise-Induced Hearing Loss among Migrant Workers in Kuwait

Although the effect of hearing loss on years lived with disability (YLD) is quite substantial, occupational hearing loss among migrant workers is significantly under-studied. In Kuwait, where nearly two-thirds of the population are migrant workers, the burden of occupational noise-induced hearing loss (ONIHL) is unknown. The objective of the study was to assess the prevalence of ONIHL among migrant workers in Kuwait and explore workplace and individual risk factors that are associated with ONIHL. We obtained data of annual physical exams for the year 2018 conducted by the Shuaiba Industrial Medical Center (SIMC) for all industrial workers in the area. We applied univariate and multivariate logistic regression models to estimate the effects of individual and occupational characteristics on ONIHL. A total of 3474 industrial workers visited the SIMC for an annual exam. The vast majority were men (99%) and non-Kuwaitis (98%) with a median age of 38 years. A total of 710 workers were diagnosed with ONIHL with a prevalence of 20.4%. Age, years of experience, and self-reported exposure to noise were associated with statistically significant higher odds of ONIHL. When adjusted for age, years of experience, and other individual level factors, type of industry was not a statistically significant predictor of ONIHL. The study uncovers the significant burden of hearing loss among the migrant worker subpopulation in Kuwait, an area of occupational health that is often underestimated or unrecognized. Although laws and regulations are in place to prevent and control noise in the workplace, the onus is on local authorities to ensure the necessary training and controls aimed to reduce noise exposure.

The Significance of Audiometric Notching in Individuals With a History of Noise Exposure: A Systematic Review

OBJECTIVES

The diagnosis of noise-induced hearing loss (NIHL) is reliant on the appraisal of audiometric data. A notch, dip or bulge, centered at the 4-kHz frequency is considered to be pathognomonic. However, guidelines applied to assist the diagnosis of NIHL often allow for a notch centered between the 3- and 6-kHz frequencies. The primary outcome of this review is to document the relationship between audiometric notching at particular frequencies and the populations in which they have been identified.

DESIGN

We included all population-based studies, cohort, cross-sectional, case-control, case-series, and case reports of adults and children, with exposure to noise and with a notch, dip or bulge. The review has been registered with Prospero (Registration: CRD42017079901) and prepared in line with the PRISMA guidelines.

RESULTS

We included 84 articles in the final systematic review. There were a total of 1,438,987 individuals, aged 7 to 80 years old. The studies were conducted in 26 different countries. Fourteen studies identified notching at 3 kHz, 63 studies identified notching at 4 kHz, and 47 studies identified notching at 6 kHz. The Newcastle-Ottawa risk assessment tool was performed on 82 of the studies emphasizing the high risk of bias in observational studies.

CONCLUSIONS

The overwhelming outcome of this systematic review demonstrates that the relationship between noise exposure and a 3- to 6-kHz audiometric notch is not straight-forward. A handful of articles have displayed a clear association between an individual's noise exposure and an audiometric notch. Unilateral notches, notches observed at 3 kHz and notches in the absence of continued high-intensity noise exposure must be scrutinized thoroughly. The ambiguous nature of NIHL directs its continued interest.

Loud Music and Leisure Noise Is a Common Cause of Chronic Hearing Loss, Tinnitus and Hyperacusis

High sound levels capable of permanently damaging the ear are experienced not only in factories and war zones but in concert halls, nightclubs, sports stadiums, and many other leisure environments. This review summarizes evidence that loud music and other forms of "leisure noise" are common causes of noise-induced hearing loss, tinnitus, and hyperacusis, even if audiometric thresholds initially remain within clinically normal limits. Given the huge global burden of preventable noise-induced hearing loss, noise limits should be adopted in a much broader range of settings, and education to promote hearing conservation should be a higher public health priority.

Health study of 11,800 workers under occupational noise in Xinjiang

Background

We investigated the health status of some workers exposed to occupational noise in Xinjiang, and explored the influencing factors of their health level. We aimed to determine the key protection groups of occupational noise hazards, which might provide the basis for the development of targeted noise prevention measures.

Methods

We used descriptive analysis to investigate a total of 11,800 participants who underwent occupational health examination in Xinjiang Occupational Disease Prevention Hospital.

Results

The hearing abnormality rate of noise exposure participants was 8.03%, which was higher in males than females (χ² = 54.507, p < 0.05). The abnormal rate of high-frequency hearing threshold in Xinjiang minorities was lower than in Han nationality (χ² = 11.780, p < 0.05), while the results of the electrocardiogram were reversed (χ² = 9.128, p < 0.05). Differences in abnormal rates of blood pressure (χ² = 149.734, p < 0.05), hearing (χ² = 231.203, p < 0.05), and physical examination (χ² = 360.609, p < 0.05) are statistically significant in different industries. The abnormal rates of blood pressure (χ² = 67.416, p < 0.05) and hearing (χ² = 49.535, p < 0.05) gradually decrease with the expansion of the enterprise scale. Logistic regression analysis showed that gender, nationality, age, enterprise size, and industry were closely related to pure tone audiometry examination abnormal rate.

Conclusion

Workers of male, elder, in mine and small/medium enterprises should be the key populations to prevent occupational noise hazard. It is necessary to standardize occupational health management in enterprises, which helps to improve workers’ self-protection awareness and quality of life.

Sex differences in noise-induced hearing loss: a cross-sectional study in China

BACKGROUND

Significant sex differences exist in hearing physiology, while few human studies have investigated sex differences in noise-induced hearing loss (NIHL), and the sex bias in previous studies resulted in inadequate female data. The study aims to investigate sex differences in the characteristics of NIHL to provide insight into sex-specific risk factors, prevention strategies and treatment for NIHL.

METHODS

This cross-sectional study included 2280 industrial noise-exposed shipyard workers (1140 males and 1140 females matched for age, job and employment length) in China. Individual noise exposure levels were measured to calculate the cumulative noise exposure (CNE), and an audiometric test was performed by an experienced technician in a soundproof booth. Sex differences in and influencing factors of low-frequency (LFHL) and high-frequency hearing loss (HFHL) were analyzed using logistic regression models stratified by age and CNE.

RESULTS

At comparable noise exposure levels and ages, the prevalence of HFHL was significantly higher in males (34.4%) than in females (13.8%), and males had a higher prevalence of HFHL (OR = 4.19, 95% CI 3.18 to 5.52) after adjusting for age, CNE, and other covariates. Sex differences were constant and highly remarkable among subjects aged 30 to 40 years and those with a CNE of 80 to 95 dB(A). Alcohol consumption might be a risk factor for HFHL in females (OR = 3.12, 95% CI 1.10 to 8.89).

CONCLUSIONS

This study indicates significant sex differences in NIHL. Males are at higher risk of HFHL than females despite equivalent noise exposure and age. The risk factors for NIHL might be different in males and females.

Hearing threshold levels of Australian coal mine workers: a retrospective cross-sectional study of 64196 audiograms

OBJECTIVE

This study examined the hearing threshold levels (HTL) of workers commencing employment in Australian coal mines in the State of New South Wales (NSW). The aim was to establish if some degree of hearing loss was identifiable in the mandatory pre-employment audiograms of workers.

DESIGN

This was an observational, retrospective, repeated cross-sectional study.

STUDY SAMPLE

De-identified audiometric records of 64196 employees entering NSW coal mining in three representative five-year periods between 1991-2015 were utilised.

RESULTS

Although HTLs were lower (better) in more recent years, the results showed clinically significant hearing loss (≥25dBHL) for older workers, 45-60 years. Pure tone average (PTA) hearing losses were greater at the higher frequencies associated with excessive noise exposure (3-6 kHz), than at the speech frequencies (0.5-4 kHz). Hearing loss in the left ears were higher compared to the right ears, with higher prevalence of audiometric notches in males.

CONCLUSION

Almost a fifth (14.8-20.1%) of male workers commencing work in NSW coal mines presented with an audiometric notch at 4 kHz. Further research is required to determine if these notches represent true NIHL, and how the residual hearing of workers may be conserved.

Occupational Noise Exposure and Longitudinal Hearing Changes in Post-9/11 US Military Personnel During an Initial Period of Military Service

OBJECTIVES

Auditory impairments, particularly those resulting from hazardous occupational noise exposures, are pressing concerns for the US Departments of Defense (DoD) and Veterans Affairs (VA). However, to date, no studies have estimated the rate of hearing threshold change that occurs during service or how changes may vary by military occupation. Hearing threshold changes during military service have historically been reported as the proportion of Service members demonstrating a significant threshold shift. This approach does not capture the rate of the hearing threshold change or the specific audiometric frequencies impacted. Determining the rate of hearing threshold change, and factors that affect the rate of change, is important to elucidate the impact of military service on hearing and to guide prevention strategies and subsequent hearing health care. Our primary objective was to estimate the annual rate of hearing threshold change during military service as a consequence of military occupational noise exposure ranking.

DESIGN

We linked audiometric data, collected from military personnel as part of a DoD hearing conservation program, to data describing demographic and military-service characteristics obtained from individuals enrolled in the Noise Outcomes In Service members Epidemiology Study. The analytic cohort included Veterans who enlisted in military service after September 2001 (n = 246). We examined the longitudinal association between military occupations categorized as having a low, moderate, or high noise exposure ranking and pure-tone hearing thresholds (500 to 6000 Hz) using a hierarchical linear model. The average annual rate of hearing threshold change and their 95% confidence intervals were estimated by service branch, military occupational noise exposure ranking, and audiometric test frequency.

RESULTS

On average, hearing threshold change ranged between -0.5 and 1.1 dB/year and changes over time varied by service branch, audiometric test frequency, and military occupation noise ranking. Generally, higher test frequencies (3000 to 6000 Hz) and military occupations with moderate or high noise exposure rankings had the greatest average annual rates of hearing threshold change; however, no dose-response relationship was observed. Among Marine Corps personnel, those exposed to occupations with high noise rankings demonstrated the greatest average annual rate of change (1.1 dB/year at 6000 Hz). Army personnel exposed to occupations with moderate noise rankings demonstrated the greatest average annual rate of change (0.6 dB/year at 6000 Hz).

CONCLUSIONS

This study (1) demonstrates the unique use of DoD hearing conservation program data, (2) is the first analysis of hearing threshold changes over time using such data, and (3) adds to the limited literature on longitudinal changes in hearing. The difference in hearing threshold changes across military branches is likely indicative of their varying noise exposures, hearing protection device use and enforcement, and surveillance practices. Results suggest Marine Corps and Army personnel are at risk for hearing threshold changes and that, among Army personnel, this is most pronounced among those exposed to moderate levels of occupational noise exposure. Estimates of the rate of hearing threshold change by frequency and factors that impact hearing are useful to inform the DoD's efforts to protect the hearing of their Service members and to the Veterans Affairs's efforts to identify and rehabilitate those most likely to experience hearing threshold change.

Factors associated with self-rated health among mineworkers in Zambia: a cross-sectional study

Background

This study aims to examine miners’ working conditions and self-rated health status in copper mines in Zambia and to identify the conditions and factors necessary to improve the safety and health of mineworkers.

Methods

A cross-sectional study using a self-administered questionnaire was conducted anonymously among copper mineworkers in Zambia in 2015 and 2016. Five targeted mining companies among 33 were introduced by the Mineworkers’ Union of Zambia. Study participants were recruited at the waiting space for underground work, waiting rooms of company clinics/hospitals, and/or at training sessions, which were places permitted by the target companies to perform data collection via convenience sampling. Bivariate analyses (e.g., t tests, Kruskal-Wallis tests, chi-square tests, or Cochran-Armitage tests) and logistic regression analysis were used to analyze differences in demographic characteristics and to compare their working conditions, health conditions, safety management at the workplace, and training opportunities by employment status.

Results

In total, 338 responses were analyzed. Regular employees had better working conditions, including higher incomes (P = 0.001), more likely to be guaranteed sickness insurance by the company (P < 0.001), paid holidays (P = 0.094), and sick leave (P = 0.064), although the difference was not statistically significant. Mineworkers’ decreased self-rated health was determined by job category (adjusted odds ratio [AOR], 0.41; 95% confidence interval [CI], 0.21, 0.82; P = 0.012). Having experienced violence from the boss/manager (AOR, 0.54; 95% CI, 0.32, 0.91; P = 0.020) was negatively associated with better self-rated health in the crude odds ratio.

Conclusions

Among mineworkers in Zambia, nonunderground work and not having experienced violence from their boss/manager contributed to increased self-rated health. From the perspective of psychological safety and human security, the management of safety and the working environment, including human resource management and preventing harassment/violence, should be assured, especially for underground mineworkers.

Hearing loss as a predictor for hearing protection attenuation among miners

OBJECTIVE

This study investigated risk factors for poor earplug fit, with a focus on the association between hearing loss and personal attenuation ratings (PARs).

METHODS

Earplug fit was assessed by obtaining PARs using a real ear at attenuation threshold (REAT) system. Hearing loss was assessed using the unoccluded hearing thresholds measured during the REAT testing and the results of a speech-in-noise test. Potential predictors of PARs were modelled using both simple and multiple linear regression. Hearing loss was the primary predictor of interest.

RESULTS

Data were collected from 200 workers at ten above-ground mining sites in the Midwestern USA. Workers reported wearing their hearing protection on average 73.9% of the time in a high noise environment (mean 8-hour time-weighted average noise exposure 85.5 dBA, range 65-103 dBA). One-quarter (26.7%) of workers were found to have a hearing loss (hearing threshold ≥25 dB across 1-4 kHz), and 42% reported symptoms of tinnitus. Workers with a hearing loss had a significantly lower PAR than those without a hearing loss (β=-5.1, SE=1.7).

CONCLUSIONS

The results of the adjusted regression models suggest that workers with hearing loss achieved significantly lower PARs than those without hearing loss. This association between hearing loss and hearing protection devices (HPD) fit brings into focus the potential benefit of fit checks to be included in hearing conservation programmes. Workers found to have hearing loss should be prioritised for fit testing, as their hearing impairment may be associated with poor HPD fit.

Opioid-Induced Hearing Loss and Neonatal Abstinence Syndrome: Clinical Considerations for Audiologists and Recommendations for Future Research

Purpose Over the last two decades, the number of Americans misusing opioids has reached epidemic levels. With such drastic increases in opioid misuse, audiologists are more likely to have patients with opioid-induced hearing loss or neonatal abstinence syndrome (NAS) than in previous years. More attention is needed on how these increases might influence clinical practice and such a discussion could be useful for audiologists. The goal of this article, therefore, is to summarize what is currently known regarding the relationship between opioid misuse and audiology to help guide hearing health care providers (with a particular focus on opioid-induced hearing loss and NAS). This article (a) summarizes the overlap in opioid misuse and hearing loss populations, (b) describes the evidence linking opioid misuse to hearing loss, (c) discusses clinical implications that opioid-induced hearing loss and NAS have for practicing audiologists, and (d) recommends directions for future audiological research on opioid-induced hearing loss and NAS. Conclusions There is considerable overlap between populations at-risk for hearing loss and opioid misuse. Additionally, compelling evidence exists linking opioid misuse to hearing loss, but the specific causal mechanisms remain unclear, indicating a need for additional research. This article attempts to fill a gap in the audiological literature and has the potential to serve as a guide for hearing health care providers to make more informed clinical decisions regarding patients with opioid-induced hearing loss and NAS. Clinicians may wish to consider the concerns raised in this article before intervening with such concerns, especially in the absence of best practice protocols.

An overview of occupational noise-induced hearing loss among workers: epidemiology, pathogenesis, and preventive measures

Occupational noise-induced hearing loss (ONIHL) is the most prevalent occupational disease in the world. The goal of this study was to review the epidemiology, pathogenesis, and preventive measures of ONIHL among workers and provide evidence for the implementation of control measures. Literature studies were identified from the MEDLINE, PubMed, Embase, Web of Science, and Google Scholar using the search terms “noise-induced hearing loss” “prevalence”, “pathogenesis”, and “preventive measures”. The articles reviewed in this report were limited from 2000 to 2020. Articles that were not published in the English language, manuscripts without an abstract, and opinion articles were excluded. After a preliminary screening, all of the articles were reviewed and synthesized to provide an overview of the current status of ONIHL among workers. The mechanism of ONIHL among workers is a complex interaction between environmental and host factors (both genetic and acquired factors). The outcomes of noise exposure are different among individual subjects. Clinical trials are currently underway to evaluate the treatment effect of antioxidants on ONIHL. Noise exposure may contribute to temporary or permanent threshold shifts; however, even temporary threshold shifts may predispose an individual to eventual permanent hearing loss. Noise prevention programs are an important preventive measure in reducing the morbidity of ONIHL among workers.

Prevalence of hearing loss among noise-exposed workers within the services sector, 2006-2015

OBJECTIVE

The purpose of this study is to estimate the prevalence of hearing loss among noise-exposed U.S. workers within the Services sector.

METHODS

Audiograms for 1.9 million workers (158,436 within Services) from 2006 to 2015 were examined. Prevalence and adjusted risk for hearing loss as compared with a reference industry were estimated for the Services sector/sub-sectors, and all industries combined.

RESULTS

The prevalence of hearing loss within Services was 17 compared to 16% for all industries combined. However, many sub-sectors greatly exceeded the overall prevalence (10-33% higher) and/or had adjusted risks significantly higher than the reference industry. Workers in Administration of Urban Planning and Community and Rural Development had the highest prevalence (50%), and workers in Solid Waste Combustors and Incinerators had more than double the risk, the highest of any sub-sector. Some sub-sectors traditionally viewed as 'low-risk' also had high prevalences and risks.

CONCLUSIONS

Large numbers of workers within Services have an elevated risk of hearing loss and need immediate hearing conservation efforts. Additional research and surveillance are needed for sub-sectors for which there is low awareness of hearing hazards or a lack of hearing data.

Assessment of Noise Exposure and Hearing Loss Among Workers in Textile Mill (Thamine), Myanmar: A Cross-Sectional Study

Background

In a wide range of industries, noise-induced hearing loss remains one of the most prevalent occupational problems. This study aimed to assess the noise exposure level and associated factors of hearing loss among textile workers in Yangon Region, Myanmar.

Methods

A cross-sectional study was conducted at a Textile mill (Thamine), Yangon Region, from April to December 2018. In total, 226 workers who were randomly selected from 3 weaving sections participated in face-to-face interviews using a structured questionnaire. A digital sound level meter and pure-tone audiometer were used for the assessment of noise exposure level and hearing loss, respectively. Logistic regression analysis was performed to assess the associated factors of hearing loss.

Results

In total workers, 66.4% were exposed to ≥85 dB(A) of noise exposure, and the prevalence of hearing loss was 25.7%. Age ≥35 years, below high school education, hearing difficulty, tinnitus, hypertension, > 9 years of service duration in a textile mill were positively associated with hearing loss. After adjusting confounding factors, age ≥35 years (adjusted odds ratio = 6.90, 95% confidence interval = 3.45-13.82) and tinnitus (adjusted odds ratio = 2.88, 95% confidence interval = 1.13-7.37) were persistently associated with hearing loss.

Conclusion

Providing occupational hazard education and enforcement of occupational safety regulations should be taken to decrease the noise exposure level. The regular audiometry test should be conducted for assessment of hearing threshold shift. The employer needs to implement a hearing conservation program in workplace when noise exposure reaches or exceeds 85 dB(A) for 8 hours.

An overview of research trends and genetic polymorphisms for noise-induced hearing loss from 2009 to 2018

Recently, there has been increased studies in noise-induced hearing loss (NIHL). We aimed to make an overview of research trends and genetic polymorphisms for NIHL from 2009 to 2018 with VOSviewer software. A total of 2391 papers were identified for research trends analysis in NIHL and 33 studies identified for a brief review of genetic polymorphisms in human NIHL. The number of publications has been increasing over the past decade. The journal Hearing Research published the most articles (218). The USA contributed the largest number of papers (1042; 43.58%), with the most citations (18,987) and the highest H-index (60). The University of Washington was the most contributive institution. Liberman MC published the most articles (32), and Kujawa SG possessed the highest co-citations (584). Except for high-frequency keywords identified by the software, "prevalence," "oxidative stress," "hair cells," and "cochlear implant" were also the latest research frontiers. HSPA1A rs1043618, HSPA1L rs2227956, PON2 rs12026 and rs7785846, SOD2 rs2855116, KCNE1 rs2070358, KCNQ4 rs34287852, GJB2 rs3751385, PCDH15 rs7095441 and rs11004085, GRHL2 rs1981361, ITGA8 rs10508489, MYH14 rs667907, and POU4F3 rs891969 were the research hotspots and were replicated in independent samples. Inflammation response underlying NIHL has emerged and should be considered as a pioneering field in the future for the prevention of NIHL and conservation of hearing.

Cost-Effectiveness Analysis of a Military Hearing Conservation Program

INTRODUCTION

Occupational noise threatens U.S. worker health and safety and commands a significant financial burden on state and federal government worker compensation programs. Previous studies suggest that hearing conservation programs have contributed to reduced occupational hearing loss for noise-exposed workers. Many military personnel are overexposed to noise and are provided hearing conservation services. Select military branches require all active duty personnel to follow hearing conservation program guidelines, regardless of individual noise exposure. We evaluated the cost-effectiveness of a military hearing conservation program, relative to no intervention, in relation to cases of hearing loss prevented.

METHODS

We employed cost-effectiveness analytic methods to compare the costs and effectiveness, in terms of hearing loss cases prevented, of a military hearing conservation program relative to no program. We used costs and probability estimates available in the literature and publicly available sources. The effectiveness of the interventions was analyzed based on whether hearing loss occurred over a 20-yr time frame.

RESULTS

The incremental cost-effectiveness ratio of the hearing conservation program compared with no intervention was $10,657 per case of hearing loss prevented. Workers were 28% less likely to sustain hearing loss in our model when they received the hearing conservation program compared with no intervention, which reflected the greater effectiveness of the hearing conservation program. Cost-effectiveness results were sensitive to estimated values for the probability of acquiring hearing loss from both interventions and the cost of hearing protection. We performed a Monte Carlo probabilistic sensitivity analysis where we simultaneously varied all the model parameters to their extreme plausible bounds. When we ran 10,000 Monte Carlo iterations, we observed that the hearing conservation program was more cost-effective in 99% of cases when decision makers were willing to pay $64,172 per case of hearing loss prevented.

CONCLUSIONS

Conceding a lifetime cost for service-related compensation for hearing loss per individual of $64,172, the Department of Defense Hearing Conservation Program is an economically reasonable program relative to no intervention, if a case of hearing loss avoided costs $10,657. Considering the net difference of the costs and comparative benefits of both treatment strategies, providing a hearing conservation program for all active duty military workers may be a cost-effective intervention for the Department of Defense.

Occupational noise exposure: A review of its effects, epidemiology, and impact with recommendations for reducing its burden

Exposure to hazardous noise is one of the most common occupational risks, both in the U.S. and worldwide. Repeated overexposure to noise at or above 85 dBA can cause permanent hearing loss, tinnitus, and difficulty understanding speech in noise. It is also associated with cardiovascular disease, depression, balance problems, and lower income. About 22 million U.S. workers are currently exposed to hazardous occupational noise. Approximately 33% of working-age adults with a history of occupational noise exposure have audiometric evidence of noise-induced hearing damage, and 16% of noise-exposed workers have material hearing impairment. While the Mining, Construction, and Manufacturing sectors typically have the highest prevalence of noise exposure and hearing loss, there are noise-exposed workers in every sector and every sector has workers with hearing loss. Noise-induced hearing loss is preventable. Increased understanding of the biological processes underlying noise damage may lead to protective pharmacologic or genetic therapies. For now, an integrated public health approach that (1) emphasizes noise control over reliance on hearing protection, (2) illustrates the full impact of hearing loss on quality of life, and (3) challenges the cultural acceptance of loud noise can substantially reduce the impact of noise on worker health.

Untangling the genomics of noise-induced hearing loss and tinnitus: Contributions of Mus musculus and Homo sapiens

Acoustic trauma is a feature of the industrial age, in general, and mechanized warfare, in particular. Noise-induced hearing loss (NIHL) and tinnitus have been the number 1 and number 2 disabilities at U.S. Veterans hospitals since 2006. In a reversal of original protocols to identify candidate genes associated with monogenic deafness disorders, unbiased genome-wide association studies now direct animal experiments in order to explore genetic variants common in Homo sapiens. However, even these approaches must utilize animal studies for validation of function and understanding of mechanisms. Animal research currently focuses on genetic expression profiles since the majority of variants occur in non-coding regions, implying regulatory divergences. Moving forward, it will be important in both human and animal research to define the phenotypes of hearing loss and tinnitus, as well as exposure parameters, in order to extricate genes related to acoustic trauma versus those related to aging. It has become clear that common disorders like acoustic trauma are influenced by large numbers of genes, each with small effects, which cumulatively lead to susceptibility to a disorder. A polygenic risk score, which aggregates these small effect sizes of multiple genes, may offer a more accurate description of risk for NIHL and/or tinnitus.