Prevalence of Hazardous Occupational Noise Exposure, Hearing Loss, and Hearing Protection Usage Among a Representative Sample of Working Canadians

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

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

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.

The influencing factors of hearing protection device usage among noise-exposed workers in Guangdong Province: a structural equation modeling-based survey

BACKGROUND

There are numerous complex barriers and facilitators to continuously wearing hearing protection devices (HPDs) for noise-exposed workers. Therefore, the present study aimed to investigate the relationship between HPD wearing behavior and hearing protection knowledge and attitude, HPD wearing comfort, and work-related factors.

METHOD

A cross-sectional study was conducted with 524 noise-exposed workers in manufacturing enterprises in Guangdong Province, China. Data were collected on hearing protection knowledge and attitudes, HPD wearing comfort and behavior, and work-related factors through a questionnaire. Using structural equation modeling (SEM), we tested the association among the study variables.

RESULTS

Among the total workers, 69.47% wore HPD continuously, and the attitudes of hearing protection (26.17 ± 2.958) and total HPD wearing comfort (60.13 ± 8.924) were satisfactory, while hearing protection knowledge (3.54 ± 1.552) was not enough. SEM revealed that hearing protection knowledge had direct effects on attitudes (β = 0.333, p < 0.01) and HPD wearing behavior (β = 0.239, p < 0.01), and the direct effect of total HPD wearing comfort on behavior was β = 0.157 (p < 0.01). The direct effect also existed between work shifts and behavior (β=-0.107, p < 0.05). Indirect relationships mainly existed between other work-related factors, hearing protection attitudes, and HPD wearing behavior through knowledge. Meanwhile, work operation had a direct and negative effect on attitudes (β=-0.146, p < 0.05), and it can also indirectly and positively affect attitudes through knowledge (β = 0.08, p < 0.05).

CONCLUSION

The behavior of wearing HPD was influenced by hearing protection knowledge, comfort in wearing HPD, and work-related factors. The results showed that to improve the compliance of noise-exposed workers wearing HPD continuously when exposed to noise, the HPD wearing comfort and work-related factors must be taken into consideration. In addition, we evaluated HPD wearing comfort in physical and functional dimensions, and this study initially verified the availability of the questionnaire scale of HPD wearing comfort.

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 (β = 0.64, 95% confidence interval [CI] = [0.49-0.78]) and HP use (β = 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.

Self-reported dual sensory impairment and related factors: a European population-based cross-sectional survey

BACKGROUND

Data on population-based self-reported dual vision and hearing impairment are sparse in Europe. We aimed to investigate self-reported dual sensory impairment (DSI) in European population.

METHODS

A standardised questionnaire was used to collect medical and socio-economic data among individuals aged 15 years or more in 29 European countries. Individuals living in collective households or in institutions were excluded from the survey.

RESULTS

Among 296 677 individuals, the survey included 153 866 respondents aged 50 years old or more. The crude prevalence of DSI was of 7.54% (7.36-7.72). Among individuals aged 60 or more, 9.23% of men and 10.94% of women had DSI. Eastern and southern countries had a higher prevalence of DSI. Multivariable analyses showed that social isolation and poor self-rated health status were associated with DSI with ORs of 2.01 (1.77-2.29) and 2.33 (2.15-2.52), while higher income was associated with lower risk of DSI (OR of 0.83 (0.78-0.89). Considering country-level socioeconomic factors, Human Development Index explained almost 38% of the variance of age-adjusted prevalence of DSI.

CONCLUSION

There are important differences in terms of prevalence of DSI in Europe, depending on socioeconomic and medical factors. Prevention of DSI does represent an important challenge for maintaining quality of life in elderly population.

The sound of safety: exploring the determinants of prevention intention in noisy industrial workplaces

Occupational noise exposure is a pervasive issue in many industries, leading to a range of health issues and sleep disturbances among workers. Additionally, there is a strong desire among these workers to prevent industrial accidents. This study, aimed at enhancing worker health and well-being, utilized a survey distributed by the Korean Confederation of Trade Unions to field workers. Data from 1285 workers were collected and analyzed using partial least squares structural equation modeling (PLS-SEM) to identify and understand the factors affecting prevention intention in noisy work environments. Our findings indicate that health problems resulting from occupational noise exposure significantly influence insomnia, perceived severity of potential accidents, perceived benefits of preventive measures, and perceived barriers. Perceived severity was significantly correlated with prevention intention, emphasizing the role of risk perception in motivating preventive behaviors. Perceived benefits were also significantly associated with prevention intention, highlighting the importance of positive outcomes in influencing workers' behaviors. Additionally, perceived barriers showed a significant relationship with prevention intention, suggesting that overcoming these barriers is crucial in promoting preventive behaviors. Demographic factors such as gender displayed a significant association with prevention intention, while age did not. This study provides valuable insights into the multifaceted factors influencing workers' intention to prevent industrial accidents in noisy environments, underlining the importance of comprehensive data collection tools in understanding these dynamics.

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 effects of occupational noise on sleep: A systematic review

Noise exposure in the workplace is one of the most common occupational hazards, which can affect sleep in the human. The effects of occupational noise can be different than that of environmental or social noise. This study aimed to conduct a systematic review on the effects of occupational noise on various characteristics of sleep. In this study, three electronic bibliographic databases (Scopus, PubMed, and Web of Science) were systematically searched up to 14 December 2022. The search algorithm included two sets of keywords and possible combinations. The first group was keywords related to occupational noise, and the second group was keywords related to sleep. A total of 2082 articles were identified in the initial search, and 2034 articles were excluded based on exclusion criteria or lacking inclusion criteria. Finally, 48 articles met the inclusion criteria and were selected for final review. Among 13 articles identified as high quality, all studies (100%) showed that noise had a significant effect on sleep among workers in various occupations. Among 17 articles with moderate quality, thirteen studies (76.47%) indicated that noise had a significant effect on sleep among workers in different occupations. Among 18 low-quality articles, fifteen studies (83.33%) showed that noise had a significant effect on sleep. 41 out of 48 studies (85.42%) found that occupational noise can negatively impact sleep among employees in various occupations. There are at least four potential pathways for this effect, including the physiological effect of daytime noise exposure, the psychological effect of daytime noise exposure, the effect of nighttime noise exposure, and the effect of hearing problems due to noise.

Leisure noise exposure and hearing outcomes among Canadians aged 6 to 79 years

OBJECTIVE

To examine the association between individual and cumulative leisure noise exposure in addition to acceptable yearly exposure (AYE) and hearing outcomes among a nationally representative sample of Canadians.

DESIGN

Audiometry, distortion-product otoacoustic emissions (DPOAEs) and in-person questionnaires were used to evaluate hearing and leisure noise exposure across age, sex, and household income/education level. High-risk cumulative leisure noise exposure was defined as 85 dBA or greater for 40 h or more per week, with AYE calculations also based on this occupational limit.

STUDY SAMPLE

A randomised sample of 10,460 respondents, aged 6-79, completed questionnaires and hearing evaluations between 2012 and 2015.

RESULTS

Among 50-79 year olds, high-risk cumulative leisure noise was associated with increased odds of a notch while high exposure to farming/construction equipment noise was associated with hearing loss, notches and absent DPOAEs. No associations with hearing loss were found however, non-significant tendencies observed included higher mean hearing thresholds, notches and hearing loss odds.

CONCLUSION

Educational outreach and monitoring of hearing among young and middle-aged populations exposed to hazardous leisure noise would be beneficial.

A history of occupational noise exposure is associated with steep-slope audiograms and poorer self-reported hearing-aid outcomes

OBJECTIVE

To investigate the effects of previous occupational noise exposure in older adults with hearing loss on (1) audiometric configuration and acoustic reflex (AR) thresholds and (2) self-reported hearing abilities and hearing aid (HA) effectiveness.

DESIGN

A prospective observational study.

STUDY SAMPLE

The study included 1176 adults (≥60 years) with bilateral sensorineural hearing loss. Pure-tone audiometry, AR thresholds, and responses to the abbreviated version of the Speech, Spatial, and Qualities of Hearing Scale (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire were obtained, along with information about previous occupational noise exposure.

RESULTS

Greater occupational noise exposure was associated with a higher prevalence of steeply sloping audiograms in men and women and a 0.32 (95% CI: -0.57; -0.06) scale points lower mean SSQ12 total score among noise-exposed men. AR thresholds did not show a significant relation to noise-exposure status, but hearing thresholds at a given frequency were related to elevated AR thresholds at the same frequency.

CONCLUSIONS

A noise exposure history is linked to steeper audiograms in older adults with hearing loss as well as to poorer self-reported hearing abilities in noise-exposed men. More attention to older adults with previous noise exposure is warranted in hearing rehabilitation.

Noise-Related Hearing Disorder Among Vector Control Workers in Kuala Lumpur

Introduction Noise-related hearing disorder (NRHD) is the second most common sensorineural hearing loss, right after age-related hearing loss (presbycusis). It is the highest reported occupational disease and a major compensable occupational hazard in Malaysia. With the increase in dengue cases, the need for vector control workers to control the spread of dengue at the expense of being exposed to noisy fogging machines is critical. Methods This was a cross-sectional study of vector control workers conducted by a local authority in Kuala Lumpur. Participants were categorised as either vector control workers who were directly involved in fogging activities or those who were not. A self-administered questionnaire was used to collect sociodemographic, medical and occupational information. NRHD was confirmed by an audiogram test. Results This study found a high prevalence of NRHD among vector control workers exposed to fogging activity (occupational noise hazards), with 51.4% of them experiencing this condition. The predictors of NRHD include fogging status adjusted odds ratio (aOR) 1.94 (95% CI: 1.19 - 3.17), sex 18.28 (95% CI: 2.33 - 143.16) and age 2.03 (95% CI: 1.27 - 3.25). Conclusion The findings of this study imply that vector control workers are at risk of NRHD. The predictors of NRHD are fogging status, sex and age. These findings emphasise the major impact of occupational noise hazards on NRHD and emphasise the importance of addressing this issue to preserve employees' health; especially among male and older employees with chronic noise exposure.

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.

Occupational Health Hazards Among Traffic Police in South Asian Countries: Protocol for a Scoping Review

BACKGROUND

Occupational health hazards and injuries are an alarming concern among traffic police. Occupational injuries affect the physical, social, and mental well-being of police personnel, which has various public health implications. The evaluation of occupational health and safety policies and regulations for the traffic police relies on their occupational exposure and health hazard statistics and assessments.

OBJECTIVE

The purpose of this scoping review is to systematically explore, analyze, and describe relevant findings from all studies conducted on occupational exposure and associated health hazards among traffic police in South Asia.

METHODS

The scoping review will include studies that assessed occupational exposure prevalence, types, knowledge, predisposing factors, and prevention strategies. Databases like PubMed, Springer Link, EBSCOhost, the Cochrane library, and Google Scholar will be used to obtain both published and unpublished works in the English language. Relevant gray literature, including governmental and international organization reports, will be examined. After removing duplicates and screening titles and abstracts, the full-text analysis will begin. Arksey and O'Malley's methodology framework for scoping reviews will be followed. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews, the scoping review will be reported. Two qualified reviewers will independently conduct article screening and data extraction. The extracted data will then be tabulated and accompanied by an explanation to facilitate comprehension. We will extract relevant article results using NVivo (version 10; QSR International) and thematic content analysis. The included articles will be evaluated using the mixed methods appraisal tool (version 2018).

RESULTS

The scoping review will provide insight into how occupational health hazards affect traffic police physically and psychologically in South Asia. The theoretical conceptualization of different aspects of the occupational health of traffic police will emphasize future studies in this region, which will inform policy makers to revise their occupational health and safety policies and principles. It will have implications for taking necessary preventive measures in the future to reduce occupational injuries and fatalities resulting from different types of occupational hazards.

CONCLUSIONS

This scoping review will describe the overview of occupational hazards among South Asian traffic police and will provide insights for policy makers to implement changes and to adapt new strategies.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/42239.

The effect of occupational training provided to workers in a glass factory on their use of ear protectors

Objectives. This study aimed to determine the effect of occupational training applied to workers working in noisy parts of a glass factory on the use of ear protectors. Methods. The study was a semi-experimental pre-test and post-test design. It was carried out with 45 workers determined by purposeful sampling and working in a glass production factory who accepted to participate in the study. The data were collected with an information form and noise-related symptom chart, hearing health information questionnaire and observation. In the analysis of the study data, the number/percentage, χ² test, Cohen κ test and analysis of variance were used. Results. It was determined that workers pre training did not use ear protectors (100%) and there were some noise-related health complaints. There was an increase in using ear protectors (57.8%) and a decrease in their health complaints post training. It was also found that the workers' pre-training hearing health information questionnaire mean score was 11.46 ± 3.20, and post training was 13.77 ± 3.42 in the first month and 15.77 ± 2.88 in the fourth month. Conclusions. Occupational training provided to the workers increased the workers' awareness level and their rate of wearing ear protectors, and health problems caused by work-related noise started to recover.

A Systematic Literature Review of the Factors Influencing Hearing Protection Device Usage among Industrial Workers

This systematic literature review (SLR) aims to determine the factors influencing the use of hearing protection devices (HPDs) among industrial workers. This study was guided by the PRISMA Statement (Preferred Reporting Items for Systematic reviews and Meta-Analyses) review method, and four databases comprising Scopus, Science Direct, PubMed, Wiley Online Library, and Google Scholar were employed. A total of 196 articles were identified, and 28 studies on the factors associated with HPD use among industrial workers from 2006 to 2021 met the inclusion criteria. Resultantly, five main themes emerged from this review: sociodemographic (29%), interpersonal influences (18%), situational influences (18%), cognitive-perceptual (29%), and health-promoting behavior (6%) associated with HPD use among industrial workers. A total of 17 sub-themes were identified, including age, gender, educational level, noise level, working experience, social models, interpersonal support, social norms, safety climate, training, organizational support, perceived barrier, perceived susceptibility, perceived severity, perceived benefit, self-efficacy, and cues to action. The significant factors influencing workers to use HPDs are sociodemographic, interpersonal influences, situational influences, and health-promoting behavior. Future studies should focus on the cues to action toward human behavior influencing the use of HPDs, workers' health status, and comorbidities of hearing loss. Therefore, this systematic study gives valuable reference resources for up-and-coming researchers as well as new knowledge to expert professionals and academics in various industries.

Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline

Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.

Experimental investigation on composites incorporating rice husk nanoparticles for environmental noise management

Environmental noise characteristics are determined by factors besides its source. One such factor is reverberation time, which in city canyons tends to be high due to the reflective characteristics of materials commonly used in building facades. Incorporating sound absorbing materials into building facades can help improve urban environments. This research evaluates different facade materials (concrete mix, mortar mix, vinyl spackling, and epoxy resin) incorporated with rice husk nanoparticles (NPs). Rice husk, in addition to presenting good properties for acoustic absorption, is one of the main agricultural wastes worldwide. Additionally, the characteristic of rice husk nanoparticles is correlated with milling time (longer grinding times enhance production of rice husk NPs). Sound absorption coefficients levels increase for compounds with a greater amount of rice husk NPs.

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.

Identification of Noise Levels for Skill Training Activities, Equipment, Machines and Power Tools at TVET Institutes in Malaysia

The use of various machines, equipment and power tools at TVET Institute causes the institute's environment to be exposed to noise hazards that are similar to the industry. However, not much data has been published regarding noise exposure at TVET institutes. This study was carried out to document the noise exposure of work activities training in public TVET institutes in Malaysia that implement skill training programs in metal fabrication, furniture manufacturing and automotive maintenance. The identification of excessive noise, task-based noise exposure monitoring and source measurement was conducted. The noise contribution from each work activity to the daily A-weighted noise exposure level and sound pressure level emitted by machines and equipment was documented. The findings of this study recorded 20 activities with task-based noise contribution to the daily A-weighted noise exposure level between 75.3 dB and 95 dB. Based on the findings, the training environment at the TVET institutes has a risk of operating with excessive noise. The documented data can be used in planning the implementation of suitable noise control measures in TVET institutes.

Hearing loss and its associated factors among metal workshop workers at Gondar city, Northwest Ethiopia

Introduction

Noise-induced hearing loss is a permanent sensorineural deficiency, which is caused by exposure to excessive noise sound. Although noise-induced hearing loss due to industrialization is a main public health problem in Ethiopia, studies on the prevalence and associated factors of hearing loss are scarce.

Objectives

This study aimed to assess the prevalence and associated factors of hearing loss among workers at a metal workshop in Gondar city, Northwest Ethiopia.

Methods

A cross-sectional study was employed among 300 participants using a stratified sampling technique. Data were collected using an interviewer-administered questionnaire. Bivariable and multivariable logistic regressions were conducted. In the multivariable logistic regression model, adjusted odds ratios (AOR) with a 95% confidence interval (CI) and a p &lt; 0.05 were computed to determine the level of significance.

Results

The prevalence of hearing loss among metal workshop workers was 30.7% [95% CI: (25.7, 35.7)]. Age between 30 and 44 years [AOR = 2.9; 95% CI: 1.2, 7.1], age between 45 and 65 years [AOR = 3.8; 95% CI (1.5, 9.5)], cigarette smoking [AOR = 2.3; 95% CI: 1.2, 4.5], working area noise level &gt;85 dB [AOR = 2.2; 95% CI: 1.1, 6.5], working experience of 6–10 years [AOR = 1.8; 95% CI: 1.4, 6.0], working experience &gt;10 years [AOR = 3.5; 95% CI: 1.3, 4.3], and using ear protection devices [AOR = 0.3; 95% CI: 0.1, 0.6] were significantly associated with hearing loss.

Conclusion

The prevalence of hearing loss was considerably high. This study revealed that advanced age, cigarette smoking, increased working area noise level, and working experiences were found to increase the odds of having hearing loss. Therefore, it is important to emphasize metal workshop workers that are at high risk of hearing loss and develop preventive strategies to reduce the burden of this problem. Besides, minimizing working area noise levels, proper utilization of ear protection devices, and creating awareness about the impact of hearing loss are recommended.

ELSA-Brasil: a 4-year incidence of hearing loss in adults with and without hypertension

OBJECTIVE

To compare the incidence of hearing loss among adults stratified by the occurrence of hypertension, and to investigate the association between hypertension and hearing loss.

METHODS

Longitudinal observational study, part of the Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil, Longitudinal Study on Adult's Health). Data from the first and second waves were analyzed, including information from audiological assessment and general health of the subjects. As outcome, we considered the presence of hearing loss (hearing thresholds above 25 dBHL at frequencies from 500 Hz to 8 kHz) and, as exposure variable, hypertension (report of medical diagnosis of hypertension; and/or use of drugs to treat hypertension; and/or pressure systolic blood pressure ≥ 140 mmHg; or diastolic blood pressure ≥ 90 mmHg). As covariables for adjustment were considered: sex, age, education, race / ethnicity, income, smoking, diabetes, and occupational exposure to noise. Poisson regression analysis was conducted, estimating the crude and adjusted relative risks, with 95% confidence intervals, in order to assess the factors associated with hearing loss.

RESULTS

In crude analyses, the incidence of hearing loss was higher for subjects with hypertension (9.7% versus 5.4%). The crude relative risks for hearing loss was almost double (1.93; 95%CI: 1.10-3.39) for subjects with hypertension in the right ear. In the adjusted analyses, the relative risks was not significant for the hypertension variable (1.42; 95%CI: 0.75-2.67). Being 60 years or older (RR: 5.41; 95%CI: 2.79-10.50) showed a statistically significant association with hearing loss, indicating that older adults have higher relative risks for hearing loss.

CONCLUSION

In the adjusted analyses controlled for multiple risk factors there was no association between hypertension and hearing loss. The dichotomous variable age (being 60 years or older), on the other hand, has shown a significant association with hearing loss.

The Relevance of Leisure Noise to Hearing Threshold Shifts: A Longitudinal Analysis Among Adolescents

PURPOSE

The aim of this study was to analyze the association of total leisure noise exposure and hearing threshold shifts over 5 years among adolescents enrolled in the Ohrkan cohort study.

METHOD

The Ohrkan cohort of 2,148 students aged 13-19 years was recruited from 2009 to 2011 and followed up 5 years later. Complete baseline and follow-up reports on exposure and outcome were available for 989 participants. Leisure noise exposure was assessed by questionnaires, and clinical audiometric examinations were performed. Two outcomes were defined: occurrence of the Niskar notch pattern and audiometry showing maximum hearing threshold values at 3, 4, and 6 kHz (both ears). Longitudinal analysis using generalized estimating equations was performed.

RESULTS

High total leisure noise exposure, defined as an energy equivalent of a 40-hr week of > 85 dBA, was estimated for 32.7% of students at baseline and 63.8% at follow-up. A noise notch was observed in 1.1% of adolescents at baseline and 3.3% at follow-up. At baseline, the maximum measured threshold shift was 55 dB, which increased to 85 dB at the follow-up. Longitudinal analysis did not reveal an association between leisure noise exposure and hearing thresholds. Hearing threshold shifts or noise notches were associated with sex, school type, and time point of measurement.

CONCLUSIONS

No relationship was found between leisure noise and hearing thresholds. Male adolescents and those attending secondary general schools, with graduation following completion of ninth or 10th grade, had a greater likelihood of developing hearing threshold shifts. Prevention programs should focus on these risk groups.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19233462.

Does severe subacute noise exposure increase risk of new onset hypertension beyond conventional risk factors? A 30 000 person-years cohort study

OBJECTIVES

Previous studies mostly focused on the relationship between chronic environmental noise exposure and hypertension but the effects of subacute (under 4 years) exposure with severe (>85 dB) noise exposure on clinical level hypertension have not been explored. This study aimed to reveal the association between severe noise exposure and hypertension.

METHODS

The severe noise exposure group was recruited from a Common Data Model conducted for the Korean Participants Health Examination from January 2014 to December 2017. The use of antihypertensive drug and/or blood pressure of at least 140/90 mmHg was defined as new onset clinical hypertension. A multivariate Cox proportional hazard model was implemented to estimate hazard ratios and 95% confidence intervals (CI) by adjusting covariates including demographic, lifestyle, and other chemical exposure factors. Time-dependent Cox analysis and Landmark analysis were further performed as a sensitivity analysis.

RESULTS

During the 29 332 person-years follow-up with 12 412 participants of the entire cohort, new onset hypertension occurred in 1222 participants. The findings showed that severe noise exposure was associated with an increased risk of hypertension incidence in the entire cohort [final model hazard ratio 1.28 (95% CI 1.11-1.47)]. Other covariates did not attenuate the association after adjusting age and sex. Time-dependent Cox and Landmark analysis also showed significant results [hazard ratio 1.60 (95% CI 1.38-1.85) and hazard ratio 1.33 (95% CI 1.13-1.57)].

CONCLUSION

Severe noise with subacute exposure is significantly associated with hypertension development. Further studies should be implemented to clarify whether severe exposure to noise could be an important risk factor for hypertension.

Auditory changes following firearm noise exposure, a review

Firearms produce peak sound pressure levels (peak SPL) between ∼130 and 175 dB peak SPL, creating significant risk of noise-induced hearing loss (NIHL) in those exposed to firearm noise during occupational, recreational, and/or military operations. Noise-induced tinnitus and hearing loss are common in military service members, public safety officers, and hunters/shooters. Given the significant risk of NIHL due to firearm and other noise sources, there is an interest in, and demand for, interventions to prevent and/or treat NIHL in high-risk populations. However, research and clinical trial designs assessing NIHL prevention have varied due to inconsistent data from the literature, specifically with end point definitions, study protocols, and assessment methodologies. This article presents a scoping review of the literature pertaining to auditory changes following firearm noise exposure. Meta-analysis was not possible due to heterogeneity of the study designs. Recommendations regarding audiologic test approach and monitoring of populations at risk for NIHL are presented based on critical review of the existing literature.

Association of mitochondrial DNA haplogroup and hearing impairment with aging in Japanese general population of the Iwaki Health Promotion Project

Age-related hearing loss (ARHL) is a complex multifactorial disorder. Studies in animals, including mitochondria-mutator mice, and in human suggest that oxidative stress and mitochondrial disturbance play an important role in the pathoetiology of ARHL. Mitochondrial DNA (mtDNA) haplogroups are populations with genetically similar traits, and they have been reported to affect the mitochondrial function of oxidative phosphorylation. To gain further insights into the relationships between mitochondrial haplotypes and the susceptibility to cochlear aging, in this study, we aimed to elucidate how the differences in mtDNA haplogroups may affect ARHL development in Japanese general population. We focused on early onset ARHL, as the same mtDNA haplogroup can show either a negative or positive effect on systemic co-morbidities of ARHL that appear later in life. A total of 1167 participants of the Iwaki Health Promotion Project were surveyed in 2014, and 12 major haplotype groups (D4a, D4b, D5, G1, G2, M7a, M7b, A, B4, B5, N9, and F) were selected for the analysis. A total of 698 subjects aged 30 to 65 years were included in the statistical analysis, and the hearing loss group consisted of 112 males (40.3%) and 111 females (26.4%). Multiple logistic regression analysis showed that the male subjects belonging to haplogroup A had a significantly increased risk of hearing loss, whereas the female subjects belonging to haplogroup N9 had a significantly decreased risk of hearing loss. These results suggested that the mtDNA haplogroup may be an indicator for future risk of morbidity associated with ARHL.

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.

Associations of Occupational Heat Stress and Noise Exposure with Carotid Atherosclerosis among Chinese Steelworkers: A Cross-Sectional Survey

Occupational exposure to heat stress and noise at the workplace are widespread physical hazards and have been associated with an increase in both morbidity and mortality. This study aims to examine the association between occupational heat stress and noise exposure and carotid atherosclerosis in Chinese steelworkers. A total of 3471 subjects were included in this study. Carotid plaque was measured using ultrasonography. The occupational information was collected by face-to-face personal interviews and all of the reported information was verified with the company's records. Workers were divided into non-exposure and exposure groups according to the company's records regarding previous and/or current heat stress and noise exposure status in the workplace. The prevalence of carotid plaque was 30.1% in the study population and workers exposed to both occupational heat stress and noise had the highest prevalence of carotid plaque at 37.2%. The odds of carotid plaque in individuals of different exposure status were significantly elevated after adjustment for potential confounders, especially in the heat stress and noise exposure combination group: OR = 1.32, 95% CI: 1.06 to 1.65, in individuals who had experienced heat stress exposure; OR = 1.49, 95% CI: 1.18 to 1.88, in individuals who had experienced noise exposure; OR = 2.02, 95% CI: 1.60 to 2.56, in the combination group. No significant association in female workers and no significant multiplicative or additive interactions were found between occupational heat stress and noise exposure and carotid plaque. Exposure to occupational heat stress and noise are statistically associated with carotid atherosclerosis among male steelworkers.

Health and work in Brazil: physical and psychosocial demands

This study aims to describe the prevalence and factors associated of physical and psychosocial demands among Brazilian workers. Data were obtained from the 2013 Brazilian National Health Survey. Physical demand was defined as jobs that require intense physical effort or excessive walking, whereas psychosocial demand was defined as involvement in stressful activities. Multivariate logistic regression was used to estimate the association between demands and health conditions, occupational characteristics, and work conditions. Out of 39,590 participants, 54.4% reported physical demands and 35.5% psychosocial demands at work. After adjustment for sociodemographic characteristics, health conditions, occupational characteristics, and work conditions remained significantly associated with physical or psychosocial workload. The results suggest that in Brazil the work has a high level of physical and psychosocial demands, which are associated with occupational features and health conditions. It is necessary to incorporate work activities as significant factors to investigate the causes of diseases. And the interventions and policies aimed at preventing the negative occupational exposures are urgent, and can contribute to improve physical and psychosocial health at the workplace.

Hearing Loss and Associated Factors Among Noise-Exposed Workers in Palm Oil Mills

Introduction

Almost 90% of the reported occupational diseases in Sabah, Malaysian Borneo were due to hearing loss. The manufacturing industry was the main contributor to this problem. This study aims to identify the prevalence and associated factors for hearing loss among workers in the palm oil manufacturing industry in Sabah.

Material and Methods

A cross-sectional study was done among 312 respondents from five palm oil mills in Sabah from January to April 2019. Audiometric tests, validated questionnaires and sound level meters were used. Chi-square test and independent t-test were conducted to determine the associated factors for hearing loss.

Results

75% (n = 234) of the respondents were diagnosed with hearing loss. Most of them were male (96.2%) with a mean age of 44.4 (SD 9.8) years, mean duration of employment of 16.2 (SD 9.7) years and mean noise exposure of 96.1 (SD 4.8) dB(A). The significant factors associated with hearing loss were older age (p = 0.001), married (p = 0.001), blue-collar jobs (p = 0.003), smoking (p = 0.001), works with noisy machinery (p = 0.005), lower level of noise exposed (p = 0.015), longer duration of employment (p = 0.001), and longer overtime hours per week (p = 0.001).

Conclusion

The prevalence of hearing loss among workers in the noise-exposed palm oil industries was high. Annual audiometry testing and job rotation from noise-exposed workstations were recommended. A smoking cessation program may help but reduction of noise from the source by engineering control is still the best method.

High frequency hearing impairment and cardiovascular disease in Canada: Results from the Canadian Health Measures Survey

Noise-induced stress may precipitate cardiovascular diseases. This research assessed the association between sensorineural bilateral high frequency hearing loss (HFHL), as an indication of excessive noise exposure, and cardiovascular outcomes. Participants (n = 6318, ∼50% male) 20-79 years were recruited through the cross-sectional Canadian Health Measures Survey. Questionnaires included several demographic and health-related variables. Audiometry and blood/urine collection took place in a mobile examination centre. Average thresholds ≥25 dB averaged across 3, 4, and 6 kHz defined HFHL. Logistic or linear regression models explored associations between HFHL and cardiovascular-related risk factors/outcomes. Adjusted models indicated elevated diastolic blood pressure in respondents with normal hearing, X¯ = 72.52 (95% confidence interval: 71.85-73.18) compared to the group with bilateral HFHL, X¯ = 70.28 (95%CI: 69.13-71.43), p < 0.05. Average total cholesterol, high-density lipoprotein, low-density lipoprotein and apolipoprotein A1 were elevated in the normal hearing group (p < 0.05). Insulin, high-sensitivity C-reactive protein, and average resting heart rate were elevated in the group with bilateral HFHL, p < 0.05. A stratified analysis by sex- and age, or history of loud occupational noise exposure, did not change the overall results. Although some findings warrant further exploration, the overall analysis did not provide compelling evidence for an association between HFHL and cardiovascular-related biomarkers, or cardiovascular diseases among Canadians aged 20-79 years.

Self-reported occupational noise exposure and cardiovascular disease in Canada: Results from the Canadian Health Measures Survey

Self-reported occupational noise exposure has been associated with impaired hearing, but its relationship with extra-auditory affects remains uncertain. This research assessed the association between self-reported occupational noise exposure and cardiovascular outcomes. Participants (n = 6318, ∼50% male) from the Canadian Health Measures Survey (2012-2015) aged 20-79 years were randomly recruited across Canada. An in-person household interview included basic demographics, perceived stress, diagnosed health conditions, and self-reported exposure to a noisy work environment. Direct physiological assessment in a mobile examination centre permitted the determination of biomarkers/risk factors related to cardiovascular function. Logistic or linear regression models explored the association between self-reported occupational noise exposure and several cardiovascular endpoints after adjusting for confounding variables. After adjustments, there was no evidence for an association between occupational noise and any of the evaluated endpoints, which included but were not limited to blood pressure, heart rate, blood glucose, insulin, lipids, diagnosed hypertension, medication for hypertension, myocardial infarction, stroke, or heart disease. There was no evidence that self-reported occupational noise exposure was associated with evaluated cardiovascular-related biomarkers, or cardiovascular diseases among Canadians aged 20-79 years. This study, and others like it, provides an important contribution to an evidence base that could inform policy related to occupational 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.

Noise Damage Accelerates Auditory Aging and Tinnitus: A Canadian Population-Based Study

OBJECTIVE

Age-related hearing loss (ARHL) is the third most challenging disability in older adults. Noise is a known modifiable risk factor of ARHL, which can drive adverse health effects. Few large-scale studies, however, have shown how chronic noise exposure (CNE) impacts the progression of ARHL and tinnitus.

STUDY DESIGN

Retrospective large-scale study.

SETTING

Audiology clinical practice.

PATIENTS

In this study, 928 individuals aged 30-100 years without (n=497) or with the experience of CNE (n=431) were compared in their hearing assessments and tinnitus. In order to only investigate the impact of CNE on ARHL and tinnitus, people with other risk factors of hearing loss were excluded from the study.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Noise damage was associated with a greater ARHL per age decades (pure-tone average(PTA)0.5-4kHz alterations 19.6-70.8 dB vs. 8.0-63.2 dB, ≤0.001), an acceleration of developing a significant ARHL at least by two decades (PTA0.5-4kHz 33.4 dB at 50-59yr vs. 28.2 dB at 30-39yr, ≤0.001), and an increased loss of word recognition scores (total average 84.7% vs. 80.0%, ≤0.001). Significant noise-associated growth in the prevalence of tinnitus also was shown, including more than a triple prevalence for constant tinnitus (28.10% vs. 8.85%, ≤0.001) and near to a double prevalence for intermittent tinnitus (19.10% vs. 11.10%, ≤0.001). Noise also resulted in the elevation of the static compliance of the tympanic membrane throughout age (total average 0.61 vs. 0.85 mmho, ≤0.001).

CONCLUSIONS

Our findings emphasize the significant contribution of CNE in auditory aging and the precipitation of both ARHL and tinnitus.

Are occupational and environmental noises associated with periodontitis? Evidence from a Korean representative cross-sectional study

BACKGROUND

Evidences have shown that noise could be a risk factor for cardiovascular and metabolic diseases. Since periodontitis and CVD are characterized by inflammation, it is reasonable to doubt that occupational/environmental noise is a risk factor for periodontitis. The aim of this study was to examine the relationship between occupational/environmental noise and periodontitis in a nationally representative sample of Korean adults.

METHODS

This cross-sectional study used data from the 7th Korean National Health and Nutrition Examination Survey. The study sample included 8327 adults aged 40 to 80 years old. Noise exposure and the duration of the exposure were assessed with self-report questionnaires. The dependent variable was periodontitis. Age, gender, place of residence, income, marital status, smoking, frequency of daily tooth brushing, recent dental checkup, and diabetes were included as covariates. Logistic regression analyses estimated the association between noise exposure and periodontitis.

RESULTS

Those who were exposed to environmental noise during their lifetime had an increased prevalence of severe periodontitis (odds ratio [OR] 1.88; 95% confidence interval [CI] 1.05 to 3.40), and this association was strengthened as the duration of the environmental noise exposure was longer (OR of > 120 months 2.35 and OR of ≤120 months 1.49). There was a combined relationship for severe periodontitis between occupational and environmental noise exposure (OR of both exposures 2.62, OR of occupational exposure only 1.12, and OR of environmental exposure only 1.57).

CONCLUSION

Our study shows that noise exposure is associated with periodontitis, and the association was higher in the synergism between occupational and environmental interaction.

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.

Acoustic-Perceptual Correlates of Voice Among Steam Train Engineers: Effects of Noise and Hearing Protection

Occupational voice users are at a higher risk for developing voice disorders due to their vocal demands, such as prolonged periods of work-related voice use and nonideal environmental factors, such as speaking above background noise. The current study focused on the effects of background noise and hearing protection on acoustic-perceptual correlates of voice among steam train engineers. Fourteen participants phonated vowel /a/, read a phrase, and described a map under different noise and hearing protection conditions. Relative sound pressure level, relative fundamental frequency, and perceived vocal effort and disturbance decreased in the presence of hearing protection for all noise conditions. In contrast, these acoustic measures increased in the absence of hearing protection supporting Lombard effect. Overall, results of the current study provide insight into possible risks to vocal health in workers exposed to high levels of background noise and use hearing protection.

Personal listening device usage among Canadians and audiometric outcomes among 6-29 year olds

OBJECTIVE

To describe personal listening device (PLD) usage and sociodemographic variables among a nationally representative sample of Canadians and examine audiometric outcomes among a subsample.

DESIGN

Audiometry and in-person questionnaires were used to evaluate hearing and PLD usage across age, sex, household income/education level. PLD exposure was quantified using a common occupational noise limit.

STUDY SAMPLE

A randomised sample of 10,460 respondents, aged 6-79, with audiometric analysis of a subsample (n = 4807), aged 6-29, tested between 2012 and 2015.

RESULTS

Loud PLD usage was reported by19.5% of Canadians. The highest prevalence was among teenagers (44.2%) and young adults (36.3%). Among children, 13.1% of users listened at loud volumes. High PLD usage (equivalent to or above 85 dBA, LEX 40) among 12-19 year olds was double that of 20-29 year olds: 10.2% versus 5.1%^E. Five years or more of loud PLD usage was associated with significantly higher mean hearing thresholds compared to less years. No association between loud or high PLD usage and mean thresholds were found.

CONCLUSION

The majority used PLDs safely, however a small proportion reported high risk usage which will impact hearing should this pattern persist over many years.

Occupational Noise: Auditory and Non-Auditory Consequences

Occupational noise exposure accounts for approximately 16% of all disabling hearing losses, but the true value and societal costs may be grossly underestimated because current regulations only identify hearing impairments in the workplace if exposures result in audiometric threshold shifts within a limited frequency region. Research over the past several decades indicates that occupational noise exposures can cause other serious auditory deficits such as tinnitus, hyperacusis, extended high-frequency hearing loss, and poor speech perception in noise. Beyond the audiogram, there is growing awareness that hearing loss is a significant risk factor for other debilitating and potentially life-threatening disorders such as cardiovascular disease and dementia. This review discusses some of the shortcomings and limitations of current noise regulations in the United States and Europe.

Effectiveness of a Novel Index System in Preventing Early Hearing Loss among Furniture Industry Skills Training Students in Malaysia

Occupational noise-induced hearing loss (ONIHL) is the most reported occupational disease in Malaysia. ONIHL is aggravated by the presence of early hearing loss amongst the youth prior to entering a real working environment. At technical and vocational education training (TVET) institutions, students may develop early ONIHL because training workshops are designed imitating the industrial working environment to produce skilled workers. The exceeding noise level at workshops and recent risk of non-occupational noise can cause early ONIHL among these students. Therefore, ONIHL must be addressed at the early stage of producing skilled workers. Octa hearing conservation index (OHCI) system is developed as a management and monitoring tool for hearing conservation program (HCP) in TVET institutions. Six existing and two new HCP components were used to build the index system. A pilot test on the effectiveness of the OHCI system was conducted in a selected TVET institution for six months. The post-HCP shows a 52.6% improvement compared to the pre-HCP. The implementation of HCP has shown improved awareness on the hazards of loud noise exposure and active use of hearing protection devices among participants. The OHCI system has a great potential as a tool to improve HCP implementation in TVET institutions, and eventually, industry.

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.

Noise Induced Hearing Loss and Tinnitus-New Research Developments and Remaining Gaps in Disease Assessment, Treatment, and Prevention

Long-term noise exposure often results in noise induced hearing loss (NIHL). Tinnitus, the generation of phantom sounds, can also result from noise exposure, although understanding of its underlying mechanisms are limited. Recent studies, however, are shedding light on the neural processes involved in NIHL and tinnitus, leading to potential new and innovative treatments. This review focuses on the assessment of NIHL, available treatments, and development of new pharmacologic and non-pharmacologic treatments based on recent studies of central auditory plasticity and adaptive changes in hearing. We discuss the mechanisms and maladaptive plasticity of NIHL, neuronal aspects of tinnitus triggers, and mechanisms such as tinnitus-associated neural changes at the cochlear nucleus underlying the generation of tinnitus after noise-induced deafferentation. We include observations from recent studies, including our own studies on associated risks and emerging treatments for tinnitus. Increasing knowledge of neural plasticity and adaptive changes in the central auditory system suggest that NIHL is preventable and transient abnormalities may be reversable, although ongoing research in assessment and early detection of hearing difficulties is still urgently needed. Since no treatment can yet reverse noise-related damage completely, preventative strategies and increased awareness of hearing health are essential.

Field Attenuation of Foam Earplugs

Background

Hearing protection devices (HPDs) are often used in the workplace to prevent hearing damage caused by noise. However, a factor that can lead to hearing loss in the workplace is improper HPD fitting, and the previous literature has shown that instructing workers on how to properly insert their HPDs can make a significant difference in the degree of attenuation.

Methods

Two studies were completed on a total of 33 Hydro One workers. A FitCheck Solo field attenuation estimation system was used to measure the personal attenuation rating (PAR) before and after providing one-on-one fitting instructions. In addition, external ear canal diameters were measured, and a questionnaire with items related to frequency of use, confidence, and discomfort was administered.

Results

Training led to an improvement in HPD attenuation, particularly for participants with poorer PARs before training. The questionnaire results indicated that much HPD discomfort is caused by heat, humidity, and communication difficulties. External ear canal asymmetry did not appear to significantly influence the measured PAR.

Conclusion

In accordance with the previous literature, our studies suggest that one-on-one instruction is an effective training method for HPD use. Addressing discomfort issues from heat, humidity, and communication issues could help to improve the use of HPDs in the workplace. Further research into the effects of canal asymmetry on the PAR is needed.

Method for protected noise exposure level assessment under an in-ear hearing protection device: a pilot study

OBJECTIVE

To properly measure the effective noise exposure level of workers with hearing protection devices (HPD), the use of in-ear noise dosimeters (IEND) is increasing. Commercial IENDs typically feature one in-ear microphone that captures all noises inside the ear and do not discriminate the residual noise in the earcanal from wearer-induced disturbances (WID) to calculate the in-ear sound pressure levels (SPL). A method to alleviate this particular issue with IENDs and calculate the hearing protection level on-site is therefore proposed.

DESIGN

The sound captured by an outer-ear microphone is filtered with the modelled HPD transfer function to estimate the in-ear SPL, this way part of the WIDs mostly captured by the in-ear microphone can be rejected from the SPL. The level of protection provided by the earplugs can then be estimated from the difference between in-ear and outer-ear SPLs. The proposed method is validated by comparing the outcome of the proposed WID rejection method to a reference method.

STUDY SAMPLE

The detailed methods are assessed on audio recordings from 16 industrial workers monitored for up to 4 days.

RESULTS

The merits of the proposed WID rejection approach are discussed in terms of residual SPL and hearing protection level estimation accuracy.

CONCLUSIONS

Based on the findings, a method to integrate the proposed WID rejection algorithm in future IENDs is suggested.

The Prevalence of Occupational Injuries and Associated Risk Factors among Workers in Bahir Dar Textile Share Company, Amhara Region, Northwest Ethiopia

Introduction

Occupational injuries are occurrences arising out of, or in the course of, work which results in a fatal or nonfatal injury, e.g., a fall from a height or contact with moving machines. They pose psychological, behavioral, social, vocational, and economic problems. No previous studies have been conducted on the prevalence and associated risk factors of occupational injuries among workers in Bahir Dar Textile Share Company (SC). Therefore, this study aimed to assess the prevalence and associated risk factors of occupational injury in Bahir Dar Textile SC, Northwest Ethiopia.

Methods

A cross-sectional study was conducted among employees of Bahir Dar Textile SC in 2019. Three hundred (195 males and 105 females) employees were selected using proportional simple random sampling from the spinning, weaving, finishing, engineering, and administration sections.

Results

The one-year and the two-week occupational injury prevalences were 42.7% and 6.7%, respectively. The one-year report from all the respondents shows that abrasion (10.7%) and eye injury (7.7%) were the two top injuries, hands (12.7%) and eyes (7.7%) were the top injured body parts, and machines (22.7%) and falling/slipping (6.3%) caused most injuries. Statistically significant differences in injuries (p < 0.05) were observed due to variations in gender, job category, exposure to vibration, exposure to rays/welding sparks, and labor-intensive work. The weaving section was positively associated with occupational injuries at AOR = 4.497 and p=0.05.

Conclusions

Occupational injuries prevalence is high over the last year. The major causes of injuries were machines and falling/slipping, while the major injuries were abrasions, eye injuries, sprains, and burns. The factors significantly associated with occupational injuries were male gender, job category, use of vibrating tools, high intensive work, and rays/welding sparks. Occupational safety and health training, use of personal protective equipment (PPE), and shifting employees from intensive works are recommended.

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.

Burden of disease: A scoping review of HIV/AIDS and TB in occupational noise-induced hearing loss

BACKGROUND

Occupational noise-induced hearing loss (ONIHL) does not occur in isolation from other influencing factors such as health conditions and illnesses like human immunodeficiency virus and acquired immunodeficiency syndrome (HIV and AIDS), as well as tuberculosis (TB). How the burden of disease influences the occurrence and/or management of ONIHL becomes a key if the goal of hearing conservation programmes (HCPs) is to be achieved within these contexts.

OBJECTIVES

The purpose of this scoping review was to conduct an investigation on how the burden of disease's influence on ONIHL is reported in literature, with a specific focus on the most prevalent diseases in South African mines - HIV and AIDS and TB.

METHOD

A scoping review was conducted using the Arksey and O'Malley's framework. A search was conducted in five electronic bibliographic databases and the grey literature.

RESULTS

The search procured 10 publications, with two specific to ONIHL within the South African context. In addition to the two publications specific to TB and ONIHL, findings revealed a serious gap in the evidence around the scoping review question globally. This obvious lack of investigations into the influence of these two conditions in the South African mining context raises serious implications about the responsiveness, and proactive nature of HCPs within this population.

CONCLUSION

Considering the burden of diseases on otology and audiology is critical as certain diseases cause hearing impairment either as a primary effect, as a secondary/opportunistic effect or as a side effect of treatment options for that disease. An employee suffering from any such disease with concomitant exposure to hazardous noise levels presents an even bigger challenge to HCPs if such is not taken into consideration in the conception, implementation and monitoring of HCPs.

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.

[Prevalence of exposure to occupational noise in Brazilian workers: results of the Brazilian National Health Survey, 2013]

The objectives were to describe the prevalence of occupational exposure to noise and to analyze associated factors in the Brazilian population. This cross-sectional population-based study used data from the Brazilian National Health Survey (PNS, 2013). The sample consisted of 36,442 Brazilians 18 years or older. The outcome variable was self-reported exposure to noise during work. To assess possible factors associated with exposure to noise, we used Pearson's chi-square test and the univariate and multivariate Poisson model with robust variance. The results showed 32.1% prevalence of exposure to noise, varying from 40.9% (Santa Catarina, Brazil) to 21.9% (Piauí, Brazil). Prevalence was lower in women (PR = 0.57; 95%CI: 0.55-0.59) and in individuals 55 years or older (PR = 0.70; 95%CI: 0.65-0.76). Higher prevalence was associated with the 25-54-year age bracket (PR = 1.00; 95%CI: 0.95-1.06), middle schooling level (PR = 1.36; 95%CI: 1.29-1.44), self-reported fatigue (PR = 1.35; 95%CI: 1.30-1.40), hearing impairment (PR = 1.27; 95%CI: 1.19-1.35), and history of work-related accident (PR = 1.37; 95%CI: 1.25-1.50). Prevalence of self-reported exposure to occupational noise was higher than in three other Latin American countries. Higher prevalence among men, younger workers, and those with less schooling was expected. The associations with auditory and non-auditory problems suggest the need for systemic interventions. Adjustments to the questions in the PNS are desirable to favor comparability and monitoring.