Managing acoustic noise within MRI: A qualitative interview study among Swedish radiographers.

INTRODUCTION: Acoustic noise from magnetic resonance imaging (MRI) can cause hearing loss and needs to be mitigated to ensure the safety of patients and personnel. Capturing MR personnel's insights is crucial for guiding the development and future applications of noise-reduction technology. This study aimed to explore how MR radiographers manage acoustic noise in clinical MR settings. METHODS: Using a qualitative design, we conducted semi-structured individual interviews with fifteen MR radiographers from fifteen hospitals around Sweden. We focused on the clinical implications of participants' noise management, using an interpretive description approach. We also identified sociotechnical interactions between People, Environment, Tools, and Tasks (PETT) by adopting a Human Factors/Ergonomics framework. Interview data were analyzed inductively with thematic analysis (Braun and Clarke). RESULTS: The analysis generated three main themes regarding MR radiographers' noise management: (I) Navigating Occupational Noise: Risk Management and Adaptation; (II) Protecting the Patient and Serving the Exam, and (III) Establishing a Safe Healthcare Environment with Organizational Support. CONCLUSION: This study offers insights into radiographers' experiences of managing acoustic noise within MRI, and the associated challenges. Radiographers have adopted multiple strategies to protect patients and themselves from adverse noise-related effects. However, they require tools and support to manage this effectively, suggesting a need for organizations to adopt more proactive, holistic approaches to safety initiatives. IMPLICATIONS FOR PRACTICE: The radiographers stressed the importance of a soundproofed work environment to minimize occupational adverse health effects and preserve work performance. They acknowledge noise as a common contributor to patient distress and discomfort. Providing options like earplugs, headphones, mold putty, software-optimized "quiet" sequences, and patient information were important tools. Fostering a safety culture requires proactive safety efforts and support from colleagues and management.

Noise risk assessment practices of four South African manufacturing and utilities companies.

BACKGROUND:  The South African Noise Induced Hearing Loss (NIHL) Regulations, mandates employers to conduct a noise risk assessment, which records specific variables for determining the status of exposure and the need for implementation of control measures. OBJECTIVES:  The study evaluated company noise risk assessment practices for alignment with legal requirements and specific risk assessment guidelines. METHOD:  Convenience sampling was used to select the four manufacturing and utilities companies that participated in the study. The participating companies submitted latest noise risk assessment records for evaluation through the READ approach. RESULTS:  The noise risk assessment records of three of the four companies omitted the recording of factors such as the reasonable deterioration in or failure of control measures, adequate control and formalisation of hearing conservation programmes (HCPs). When evaluated against the South African National Standard 31000 Risk Assessment guidelines, the risk assessment processes of the respective companies were lacking in addressing aspects related to establishing communication and consultation, evaluation, adapting, continually improving, leadership and commitment, and integration. CONCLUSION:  The recorded information on the noise risk assessment reports from the four participating companies were incomplete, negatively affecting subsequent HCP management processes and decision-making. Future studies should investigate other aspects such as the implementation status of recommended noise controls as well as their effectiveness as recorded in the noise risk assessment records.Contribution: This study provided firsthand insights of company noise risk assessment practices, specifically identifying functional and technical areas requiring improvement to enhance current efforts directed towards the minimisation of NIHL within HCPs. The study highlighted that the current practices on recording noise risk assessment information remain incomplete, adversely diminishing the impact of the assessment as an important decision-making tool. The identified technical issues specifically, when addressed, will increase trust on the decisions derived from noise risk assessments.

Impulse noise measurement in view of noise hazard assessment and use of hearing protectors.

Experience shows the occurrence of situations when the measurements of impulse noise parameters are made with measurement equipment unsuitable for such conditions. The results of using such equipment were compared with the results of using equipment with a sufficiently large upper limit of the measurement range. The analysis was carried out on the example of noise generated during shots from a Mossberg smooth-bore shotgun and AKM rifle, as well as produced in the forge. The use of the unsuitable equipment allowed to indicate the exceeding of the exposure limit value of the peak value of the signal (LCpeak), but this is not always possible when determining the energy properties of the signal (LEX,8h). While the inadequate properties of the measurement equipment will generally not prevent the conclusion that noise in a particular workplace is hazardous to hearing, the results of measurements cannot be used to select hearing protectors.

Effects of hearing protector devices on speech intelligibility: the importance of individualized assessment.

Objectives. This study aimed to compare speech intelligibility in noise with and without hearing protection devices (HPDs). Methods. Fifty-one workers were distributed into three groups: noise-induced hearing loss group (NIHLG), normally hearing noise-exposed group (NG) and normally hearing non-exposed to noise group (CG). A free field system was used to emit monosyllables (65, 70 and 75 dB) and pink noise in different signal-to-noise ratios (SNRs) (0, -5, -10 and -15). Results. In situations with HPDs, all groups showed a decrease in the percentage of correct responses with an increase in noise level. The HPD had little effect on speech intelligibility in the NIHLG and NG. Considering the effect caused by the HPD on speech intelligibility, it was observed that the group with the greatest loss was the CG for SNRs of -5, -10 and -15. Conclusion. Although speech intelligibility is influenced by the hearing threshold, the noise level and SNR are crucial for good speech intelligibility, either with or without an HPD. It is highlighted that the NG had worse results when compared with the CG, which may indicate changes in the auditory pathway resulting from continuous noise exposure, even in the absence of changes in the audiometric thresholds.

[Risk assessment on noise-induced hearing loss of 488 workers in a petrochemical plant].

Objective: To assess the risk of noise-induced hearing loss in workers from a petrochemical plant. Methods: In October 2020, 488 male workers exposed to noise in a petrochemical plant in Guangdong Province were selected by cluster sampling. Acoustics-Estimation of Noise-Induced Hearing Loss (ISO 1999: 2013) was used to assess the risk of noise-induced hearing loss of workers, and individual fit testing was used to evaluate the sound attenuation obtained by the workers. The risk assessment results and fitness test results of workers with different hearing levels were compared. Results: The average noise exposure equivalent sound level of the workers in the petrochemical plant was 86.7 dB (A) . The median of PARs (personal attenuation ratings) was 16 (4, 23) dB. There were statistically significant differences in age and service years among workers with different hearing results (P<0.05) , but no statistically significant differences in noise intensity and PARs (P>0.05) . According to risk assessment results of ISO 1999: 2013, the current risk of high-frequency hearing loss in 488 workers were negligible risk and acceptable risk. The risk of noise-induced deafness weredivided into three levels: negligible risk in 452 workers (92.7%) , medium risk in 27 workers (5.5%) and high risk in 9 workers (1.8%) . The risk of high-frequency hearing loss in next 5 to 15 years for workers with noise exposure level of >94 to 97 dB and >97 dB or above would be medium risk or above. The risk of noise-induced deafness in next 5 to 15 years for workers exposed to noise withlevel of 91 to 94 dB would be medium risk or above. Conclusion: The risk of noise-induced hearing loss in workers from the petrochemical plant is high in next 5 to 15 years, and noise prevention and control measures need to be strengthened. ISO1999: 2013 assessment method may underestimate the risk of hearing loss among workers.

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.

A scoping review to identify strategies that work to prevent four important occupational diseases.

BACKGROUND: Despite being largely preventable, many occupational diseases continue to be highly prevalent and extremely costly. Effective strategies are required to reduce their human, economic, and social impacts. METHODS: To better understand which approaches are most likely to lead to progress in preventing noise-related hearing loss, occupational contact dermatitis, occupational cancers, and occupational asthma, we undertook a scoping review and consulted with a number of key informants. RESULTS: We examined a total of 404 articles and found that various types of interventions are reported to contribute to occupational disease prevention but each has its limitations and each is often insufficient on its own. Our principal findings included: legislation and regulations can be an effective means of primary prevention, but their impact depends on both the nature of the regulations and the degree of enforcement; measures across the hierarchy of controls can reduce the risk of some of these diseases and reduce exposures; monitoring, surveillance, and screening are effective prevention tools and for evaluating the impact of legislative/policy change; the effect of education and training is context-dependent and influenced by the manner of delivery; and, multifaceted interventions are often more effective than ones consisting of a single activity. CONCLUSIONS: This scoping review identifies occupational disease prevention strategies worthy of further exploration by decisionmakers and stakeholders and of future systematic evaluation by researchers. It also identified important gaps, including a lack of studies of precarious workers and the need for more studies that rigorously evaluate the effectiveness of interventions.

South African hearing conservation programmes in the context of tele-audiology: A scoping review.

BACKGROUND: The limited involvement of audiologists in occupational noise-induced hearing loss (ONIHL) management through hearing conservation programmes (HCPs) is a global issue. In low- and middle-income (LAMI) countries such as South Africa, this is also exacerbated by demand versus capacity challenges. Tele-audiology is an option requiring serious deliberation by the audiology community within HCPs in LAMI contexts. OBJECTIVES: This scoping review explores if tele-audiology has a potential value in HCPs and reviews what has been documented in the literature on the use of tele-audiology in HCPs. METHOD: A scoping review was conducted using the Arksey and O'Malley's framework. A search was conducted in five electronic bibliographic databases including Science Direct, PubMed, Scopus Medline, ProQuest and Google Scholar and the grey literature to identify publications presenting considerations around tele-audiology in the implementation of HCPs. RESULTS: Findings revealed significant dearth of evidence specific to the use or application of tele-audiology in ONIHL and/or HCPs both within the African context and internationally, despite the purported potential benefit of this service delivery model, particularly in resource-constrained contexts such as LAMI countries. Of the publications deemed potentially relevant to this scoping review, none were found that specifically investigated or addressed the use of tele-audiology in ONIHL or HCPs as their main objective. Nuanced analysis of publications revealed that in the last decade, indication for potential growth in the use of tele-audiology within occupational audiology is indicated. CONCLUSION: Because of the significant demand versus capacity challenges in LAMI countries, and because of the need for scaling up audiology professionals' management of HCPs, careful consideration of teleaudiology as a platform to deliver services in these contexts is required.

Risk versus benefit: Should not audiologists assess this in the context of occupational noise-induced hearing loss in the mining industry?

BACKGROUND: Hearing conservation programmes (HCPs) are an important aspect of occupational health efforts to prevent occupational noise-induced hearing loss (ONIHL). In low- and middle income (LAMI) countries, where the incidence of ONIHL is significant, it is important to deliberate on the risk or benefit of HCPs. OBJECTIVES: This article is an attempt at highlighting important strategic indicators as well as important variables that the occupational health and audiology community need to consider to plan efficacious HCPs within the South African mining context. METHOD: The current arguments are presented in the form of a viewpoint publication. RESULTS: Occupational audiology vigilance in the form of engagement with HCPs in the mining industry has been limited within the South African research and clinical communities. When occupational audiology occurs, it is conducted by mid-level workers and paraprofessionals; and it is non-systematic, non-comprehensive and non-strategic. This is compounded by the current, unclear externally enforced accountability by several bodies, including the mining industry regulating body, with silent and/or peripheral regulation by the Health Professions Council of South Africa and the Department of Health. The lack of involvement of audiologists in the risk or benefit evaluation of HCPs during their development and monitoring process, as well as their limited involvement in the development of policies and regulations concerning ear health and safety within this population are probable reasons for this. CONCLUSIONS: Increased functioning of the regulatory body towards making the employers accountable for the elimination of ONIHL, and a more central and prominent role for audiologists in HCPs, are strongly argued for.

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.

Assessment of Safe Listening Intentional Behavior Toward Personal Listening Devices in Young Adults.

Recreational noise-induced hearing loss (RNIHL) is a highly preventable disorder that is commonly seen in teenagers and young adults. Despite the documented negative effects of RNIHL, it is still challenging to persuade people to adopt safe listening behaviors. More research is needed to understand the underlying factors guiding listeners' intentions to engage in safe listening habits. We used the Theory of Planned Behavior (TPB) to identify attitudes, social norms, and behavioral control in 92 young adults toward two intentional behaviors related to safe listening habits while listening to their personal listening devices: (1) lowering the intensity of loud music, and (2) shortening the listening duration of loud music. Using a Qualtrics survey, the major factors of the TPB model as they relate to the participants' intention to engage in risk-controlling behavior were assessed. Behavioral intentions to turn the music down and listen for shorter durations were thought to be predicted by the TPB factors (attitudes, social norms, and perceived behavioral control). Linear regression findings indicated that the overall TPB models were significant. Positive attitudes toward turning the music down and shortening the durations were significantly associated with intentions to engage in non-risky behavior, more so for the former behavior.

Collaborative Approaches to the Support of People with Disabilities: The Underserved and Unserved.

BACKGROUND: Underserved and unserved people are individuals who lack necessary health services. They can be found in both high- and low-income countries with disabilities in areas such as speech, language, hearing, swallowing, physical, and neurological, as well as other health problems. In addition, academic programs that prepare students to serve underserved or unserved communities do not exist in some countries. Collaborative projects allow those with expertise to share their knowledge, strategies, methods, and technologies with health practitioners, administrators, educators, students, and families. The goal is to assist populations who require special services. Collaborative projects can be interdisciplinary, international, or involve academic institutions or organizations. It is also essential that collaboration projects consider the strengths and assets that are present in the environment and in the population. This asset-based approach supports sustainability as long-term solutions can take advantage of existing strengths. Sustainability is essential so that the goals of projects can continue to contribute to a population. OBJECTIVES: The primary objective of this article is to present collaborative projects that positively impact underserved and unserved populations. The strengths of these projects are also presented as a model for further work. SUMMARY: This article presents several collaborative projects, along with the impact of these efforts.

Awareness, attitudes, and beliefs about music-induced hearing loss: Towards the development of a health communication strategy to promote safe listening.

OBJECTIVE: Worldwide, 1.1 billion young people are at risk of developing hearing loss due to unsafe listening. The World Health Organization plans a global health campaign to promote behavior change. In an effort to develop effective evidence-based interventions, this study identifies modifiable factors that influence listening habits. METHODS: Online survey among 1019 individuals aged 18-35. The questionnaire was based on theories of behavior change. RESULTS: Individuals not contemplating change showed a lack of knowledge, tended not to feel particularly at risk, and did not see the benefits of preventive measures. Conversely, those considering a change perceived more barriers (e.g., lack of information on how to act,). Self-efficacy was shown to play an ambivalent role. CONCLUSION: Four factors that can be influenced by a health communication intervention were identified: risk perception, perceived safe listening level due to a lack of symptoms, knowledge, and perceived benefits and barriers, in particular perceived loss of pleasure. PRACTICE IMPLICATIONS: The first aspects can be influenced through health communication interventions. Influencing the perceived loss of pleasure additionally requires an analysis of competing pressures. To support and not exceedingly burden the individual, we further suggest to address environmental aspects (e.g., policies).

Military and industrial performance: the critical role of noise controls.

Noise control is a well understood and important engineering skill. The science has been developed to address operational needs of being quiet on the one hand, and avoiding hearing loss on the other, both in industry and military operations. Noise control is also the first priority step in systems safety risk mitigation for noise hazards, as evidenced in U.S. industry by the requirement stated in Federal OSHA regulation 1910.95: "(b)(1) When employees are subjected to sound exceeding those listed in Table G-16, feasible administrative or engineering controls shall be utilized." In actual practice, engineering controls are of first preference, while the second step is administrative noise controls, reducing noise exposures by removing personnel from high-noise environments. The third is the use of personal protective equipment (PPE), commonly known as earmuffs and earplugs. Each of these topics is discussed herein. The U.S. Navy has developed and/or implemented many groundbreaking noise control efforts on ships, and that provides the basis of discussion in this article. This article, as an overview of noise control, also addresses issues associated with high-noise environments and consideration of noise control techniques.

Use of Personal Hearing Protection Devices at Loud Athletic or Entertainment Events Among Adults - United States, 2018.

Tens of millions of U.S. residents have a range of adverse health outcomes caused by noise exposure (1). During 2011-2012, 21 million U.S. adults who reported no exposure to loud or very loud noise at work exhibited hearing damage suggestive of noise-induced hearing loss (2). In addition to the known risk for hearing damage, nonauditory adverse health outcomes and health risks from excessive environmental sound exposure can include effects on the cardiovascular system, metabolism, blood pressure, body weight, cognition, sleep, mental health, quality of life, and overall well-being (1,3,4). CDC analyzed a representative sample of the U.S. adult population (aged ≥18 years) from a 2018 national marketing survey (50 states and the District of Columbia) that included questions about use of hearing protection devices (HPDs) (e.g., ear plugs or ear muffs) during recreational exposure to loud athletic and entertainment events; approximately 8% of respondents reported consistent use of an HPD at these types of events. Among those adults more likely to wear an HPD, 63.8% had at least some college education, and 49.1% had higher income levels. Women and older adults were significantly less likely to use HPDs. These findings suggest a need to strengthen a public health focus on the adverse health effects of excessive noise exposure at home and in recreational settings as well as a need for continued efforts to raise public awareness about the protective value of HPDs.

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.

Assessing Hearing Conservation Program Effectiveness: Results of a Multisite Assessment.

OBJECTIVES: Noise-induced hearing loss (NIHL) remains one of the most prevalent occupational diseases. Occupational hearing conservation programs (HCPs) can reduce the risk of NIHL, but there remains no consensus on assessing HCP effectiveness. We conducted a multisite, mixed-method assessment of HCP programs. METHODS: At 13 manufacturing plants, we performed assessments, including interviews with program staff and worker focus groups and surveys. We analyzed the association between these assessments and age-corrected NIHL rates. RESULTS: Only a few items from the HCP staff interviews correlated with NIHL rates. For the employee survey, management commitment to NIHL prevention and being counseled about NIHL were strongly associated with NIHL rates. CONCLUSION: Management commitment and counseling of workers about NIHL may be key factors in program effectiveness. A combination of qualitative and quantitative methods appears to be useful for assessing HCPs.

Costs and effectiveness of hearing conservation programs at 14 US metal manufacturing facilities.

OBJECTIVE: This study characterised overall and specific costs associated with hearing conservation programmes (HCPs) at US metal manufacturing sites, and examined the association between these costs and several noise-induced hearing loss (NIHL) outcomes. DESIGN: We interviewed personnel and reviewed records at participating facilities. We also measured noise for comparison to the ten-year average of measurements made by each facility. NIHL outcomes assessed included rates of standard threshold shifts (STS) and high-frequency hearing loss, as well as prevalence of hearing impairment, for each participating facility. We used linear regression to identify per-person HCP costs that best predicted the NIHL outcomes. STUDY SAMPLE: We evaluated 14 US metal manufacturing facilities operated by a single company. RESULTS: Annual HCP costs ranged from roughly $67,000 to $397,000 (average $308 ± 80 per worker). Our full-shift noise measurements (mean 83.1 dBA) showed good agreement with the facilities' measurements (mean 82.6 dBA). Hearing impairment prevalence was about 15% overall. Higher expenditures for training and hearing protector fit-testing were significantly associated with reduced STS prevalence. Higher training expenditures were also related to lower hearing impairment prevalence and high-frequency hearing loss rates. CONCLUSIONS: HCP costs were substantial and variable. Increased workplace spending on training and fit-testing may help minimise NIHL.

Cost-Effective Hearing Conservation: Regulatory and Research Priorities.

Hearing conservation programs (HCPs) mandated by the US Occupational Safety and Health Administration (OSHA) cost about $350/worker/year. Are they cost-effective? A cross-sectional model of the US adult population with and without HCPs incorporates (1) the American Medical Association's method for estimating binaural hearing impairment and whole-person impairment; (2) the model of the International Organization for Standardization (ISO) for estimating both age-related and noise-induced hearing loss; and (3) an acceptable cost of $50,000 per quality-adjusted life year. The ISO model's outputs were audiometric thresholds for groups of people with different age, sex, and noise exposure history. These thresholds were used to estimate cost per quality-adjusted life year saved for people in HCPs with different noise exposure levels. Model simulations suggest that HCPs may be cost-effective only when time-weighted average (TWA) noise exposures are ≥ 90 dBA. Enforcing existing regulations, requiring engineering noise control at high exposure levels, and using new methods that can document hearing protection device performance could improve cost-effectiveness. If the OSHA action level remains at 85 dBA-TWA, reducing the permissible exposure limit to the same level would simplify management and slightly improve cost-effectiveness. Research should evaluate employer compliance across industries, determine whether workers currently excluded from HCP regulations are at risk of noise-induced hearing loss, and develop cost-effective HCPs for mobile workers in construction, agriculture, and oil and gas drilling and servicing. Research on HCP cost-effectiveness could be extended to incorporate sensitivity analyses of the effects of a wider range of assumptions.