Hearing Conservation Programme Costs at Selected South African Companies.

The Occupational Health and Safety Act 1993 and its attending Regulations in South Africa, require employers to conduct cost analysis studies to inform decision-making related to exposure control for occupational health hazard such as noise. Cost analysis, as per South African National Standard/ISO 31000 risk assessment guideline, is an important input for the decision-making process of the risk management process. The costs of administrating a hearing conservation programme intended to minimise noise-induced hearing loss is an example of a cost analysis. This study enrolled four companies from the South African manufacturing and utilities sectors with the aim of establishing whether cost analysis is included during the noise risk assessment process; and determining administration costs of HCP administration. A HCP cost questionnaire was completed by each company's occupational hygiene professionals and risk officers. None of the companies in the study included cost analysis in their respective risk assessment processes. The overall costs, derived from the HCP cost item questionnaire, was much greater for Company A (4 290 014 Rands) than all of the other companies combined (970 685 Rands). Hearing protection device expenditures across the four companies were the greatest expense, while audiometry was the smallest expense owing to service internalisation. The HCP expenditures are incurred on periodic basis, yearly or biennial, and are internalised in companies as direct costs. Cost analysis can enhance the noise risk assessment process by providing additional input to support the decision-making process related to noise control. This challenges the occupational hygiene profession to pursue new frontiers and decision-making models in the scope of noise risk management, beyond noise measurements and hearing protection device use recommendation.

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.

Towards a practical methodology for assessment of the objective occlusion effect induced by earplugs.

The occlusion effect (OE) occurs when the earcanal becomes occluded by an in-ear device, sometimes leading to discomforts experienced by the users due to the augmented perception of physiological noises, or to a distorted perception of one's own voice. The OE can be assessed objectively by measuring the amplification of the low-frequency sound pressure level (SPL) in the earcanal using in-ear microphones. However, as revealed by methodological discrepancies found in past studies, the measurement of this objective occlusion effect (OEobj) is not standardized. With the goal of proposing a robust yet simple methodology adapted for field assessment, three experimental aspects are investigated: (i) stimulation source and the stimulus's characteristics to induce the phenomenon, (ii) measurement method of the SPL in earcanal, (iii) indicator to quantify the OEobj. To do so, OEobj is measured on human participants in laboratory conditions. Results obtained with a specific insert device suggest using the participant's own voice combined with simultaneous measurements of the SPLs based on the noise reduction method and using a single value indicator leads to a simple yet robust methodology to assess OEobj. Further research is necessary to validate the results with other devices and to generalize the methodology for field assessment.

Calibration and initial validation of a low-cost computer-based screening audiometer coupled to consumer insert phone-earmuff combination for boothless audiometry.

OBJECTIVE: To undertake calibration and preliminary validation of a custom-designed computer-based screening audiometer connected to consumer insert phone-earmuff combination for adult pure tone audiometry. DESIGN: Part 1 involved electroacoustic measurement and biological calibration of a laptop-earphone pair used for the computer-based audiometry (CBA). Part 2 compared CBA thresholds obtained without a sound booth with those measured using the gold-standard clinical audiometry. STUDY SAMPLE: 17 young normal-hearing volunteers (Part 1) and 43 normal and hearing loss subjects (Part 2) recruited from an audiology clinic via convenience sampling. RESULTS: The transducer-device combination produced outputs suitable for measuring thresholds down to 0 dB HL. Threshold pairs obtained from the CBA and clinical audiometry were highly correlated (Spearman's correlation coefficient, ρ = 0.92, p < 0.0001) and had a good degree of agreement (mean difference of -1.06 ± 7.63 dB). Also, the CBA showed about 90% sensitivity and 80% specificity for detecting hearing loss based on low (0.5, 1, 2 kHz) and high frequency (4, 8 kHz) pure tone averages of >25 dB HL. CONCLUSIONS: The use of a computer-based audiometer application with consumer insert phone-earmuff combination can offer a cost-effective solution for boothless screening audiometry.

Low-Cost Earmuff Shown to Significantly Reduce Cast-Saw Noise.

Hearing protection devices reduce cast-saw noise. It would be helpful to identify the devices that are both effective and economical. Prior studies have shown that expensive noise-reduction headphones significantly reduced the anxiety associated with cast removal with a powered oscillating saw. The cost of such headphones, however, is a drawback for some practices and hospitals. It would be helpful to determine whether lower cost ear protection can provide effective cast-saw noise reduction. In addition, it is unclear whether the noise reduction ratings (NRRs), the average sound-level reduction provided by a hearing protection device in a laboratory test, provided by manufacturers accurately characterize the effectiveness for reducing cast-saw noise. Note that noise-cancelling devices do not carry an NRR because they are not designed as hearing protectors. Five ear protection devices with different NNRs were tested. The devices varied greatly in cost and included earplugs, low-cost earmuffs, and noise-cancelling headphones. To standardize the evaluation, each device was fitted to an acoustic mannequin with high-fidelity ear microphones while a fiberglass spica cast was cut. An additional test was run without hearing protection as a control. The low-cost devices significantly reduced the saw noise, with the exception of earplugs, which had highly variable performance. The noise reduction was similar between low-cost earmuffs and the high-cost earphones when the noise-cancelling feature was not active. Active noise cancelling provided further reductions in the noise level. Patients can experience high anxiety during cast removal. The current study shows that low-cost earmuffs significantly reduce cast-saw noise. Patient care settings may be more likely to offer hearing protection that is one twenty-fifth the cost of noise-cancelling headphones. An NRR appears to be a reliable guide for selecting hearing protection that reduces cast-saw noise.

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 simple, cost-effective, and novel method for determining the efficiency of industrial and commercial noise-canceling earmuffs.

CONTEXT: There are several ways to assess the noise reducing efficiency of earmuffs, but they usually involve using human participants and/or specialized equipment. OBJECTIVE: The current study was designed to develop a less labor-intensive, cost-effective, participant-free first-pass method for measuring the efficiency of earmuffs. METHODS: We evaluated the noise-cancelling ability of five different types of earmuffs (3M: Optime 98, Optime 105; iDEA USA V201; Tronsmart Encore S6; Bose QuietComfort 35) under laboratory and field conditions. We compared our results to the microphone-in-real-ear (MIRE) method. Lastly, a survey of college-aged students was also conducted to determine which earmuffs were the most comfortable and provided the best fit. RESULTS: Of the five earmuffs studied, the Optime 98 and Bose earmuffs were most effective at reducing noise levels in both the laboratory and field. These earmuffs also received the highest scores for comfort, fit, and perceived ability to reduce noise, with Bose being slightly more preferred than Optime 98. The MIRE method provided the same overall results as the laboratory and field tests. CONCLUSION: Our method for evaluating the noise-canceling ability of earmuffs could be used to supplement more complicated testing procedures as a first-pass method.

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.

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.

Health impact and noise exposure assessment in the cricket bat industry of Kashmir, India.

AIM: The aim of the present study was to identify and evaluate predominant noise sources in the cricket bat industry of Kashmir, India. METHODS: Sound levels were measured at operator's ear level in the working zone of the workers of seven cricket bat factories. The impact assessment was made through personal interviews with each worker separately during their period of rest. RESULTS: On average, 62.5% of the workers reported difficulty in hearing and 24.1% of the workers have become patients for hypertension. Only 58.1% of the workers complained of headache due to high noise level. CONCLUSIONS: The workers engaged in the cricket bat industry of Kashmir are exposed to high noise levels. It is suggested that personal protective equipment like ear plugs and ear muffs be used by these workers as a protection against this hazard.

[Occupational Hearing Loss (BK-No. 2301) - A Retrospective Analysis of 100 Consecutive Cases]. / Lärmschwerhörigkeit (BK-Nr. 2301) ­ Eine retrospektive Analyse von 100 konsekutiven Fällen.

Introduction: In order for a diagnosis of Occupational Hearing Loss (BK-no. 2301) to be made certain criteria must be fulfilled to establish that the hearing loss is occupational in origin. This work compares 2 groups, those who fulfil the criteria (BKE) and those who do not (BKNE). Methods: A 100 consecutive reports ("Lärmgutachten BK-no. 2301") written by the authors were examined retrospectively. These recorded audiometric examination, an analysis of any tinnitus and noise exposure plus use of hearing protection. Pre- and post-noise exposure status together with an expert assessment of work limitations was made to produce a 7 point score. Results: 67% of the group fulfilled the conditions for occupational hearing loss (9% were entitled to compensation). In the BKE group 82% showed typical audiometric signs of noise damage with 75% of them fulfilling at least 6 criteria of occupational disease no. 2301. Tinnitus typical for noise exposure was found in 26%. Discussion: A 7 point score could be useful in the future as a method of helping distinguish hearing loss and tinnitus from occupational as opposed to other causes.

Providing earplugs to young adults at risk encourages protective behaviour in music venues.

For some young people, nightclubs and other music venues are a major source of noise exposure, arising from a combination of very high noise levels; relatively long attendance duration; and frequent, sustained participation over several years. Responsibility for hearing protection is largely left to individuals, many of whom choose not to wear earplugs. In order to encourage earplug use in these settings, a new approach is needed. The aim of the study was to examine whether presentation of hearing health information would result in increased use of earplugs, or whether provision of earplugs alone would be sufficient to change behaviour. A total of 51 regular patrons of music venues were allocated to either a low-information (lo-info) or high-information (hi-info) group. Both groups completed a survey about their current noise exposure, earplug usage and perceived risk of hearing damage. Both groups were also provided with one-size-fits-all filtered music earplugs. The hi-info group was also provided with audio-visual and written information about the risks of excessive noise exposure. After 4 weeks, and again after an additional 12 weeks, participants were asked about their recent earplug usage, intention to use earplugs in the future, and perceived risk of hearing damage. The results showed that after 4 weeks, the hi-info group's perceived personal risk of hearing damage was significantly higher than that of the lo-info group. After 16 weeks, these differences were no longer evident; however, at both 4 and 16 weeks, both the lo- and hi-info groups were using the earplugs equally often; and both groups intended to use earplugs significantly more often in the future. This suggests that the information was unnecessary to motivate behavioural change. Rather, the simple act of providing access to earplugs appears to have effectively encouraged young at-risk adults to increase their earplug use.

Increase in use of protective earplugs by Rock and Roll concert attendees when provided for free at concert venues.

OBJECTIVE: To determine the prevalence of hearing protection use among attendees of Rock and Roll concerts at baseline and in concerts where earplugs are provided for free at concert venue entrances. DESIGN: Six concerts performed at two music venues in Toronto, Canada were evaluated. Study personnel observed and recorded the use of hearing protection at three concerts where no earplugs were distributed, and three concerts where earplugs were provided for free at the concert venue entrance. STUDY SAMPLE: A total of 955 individuals over the age of 18 were observed at six concerts. Six hundred and thirty-seven individuals (64% male) were observed at concerts where no earplugs were provided, and 318 individuals (68% male) were observed at concerts where free earplugs were provided. RESULTS: Multivariate logistic regression demonstrated a significant increase in hearing protection usage at concerts where earplugs were provided for free at the concert venue entrance, odds ratio 7.27 (95% CI: 3.24-16.30). CONCLUSION: The provision of free earplugs at concert venues may be a simple and inexpensive intervention that could be a component of a larger public health campaign to prevent non-occupational noise-induced hearing loss.

Description and evaluation of a hearing conservation program in use in a professional symphony orchestra.

Professional orchestral musicians risk permanent hearing loss while playing their instruments. Protecting the hearing of these musicians in the workplace is critical to their ongoing ability to play their instruments, but typical workplace hearing conservation measures can have very damaging effects on the product (music) and the musicians' abilities to hear one another sufficiently. To enable effective intervention, orchestras as employers must encourage engagement with hearing protection programs and implement controls while preserving the integrity of the music. To achieve this, typical approaches used in other industries must be redesigned to suit this unique workplace. In response to these challenges, the Queensland Symphony Orchestra (Brisbane, Australia) introduced a comprehensive hearing conservation strategy in 2005 based upon best practice at the time. This strategy-which has been regularly refined-continues to be implemented on a daily basis. This investigation aimed to assess the successes, difficulties, and practical viability of the program. To achieve this a process evaluation was carried out, incorporating archival analyses, player and management focus groups, and an interview with the program's administrator. Results show the program has successfully become integrated into the orchestra's and the musicians' daily operations and significantly contributes to managing the risk of hearing loss in this population. While there is room for improvement in the orchestra's approach-particularly regarding usable personal protective devices and improved education and training, results are encouraging. This study provides a basis for those wishing to implement or evaluate similar paradigms.

[Assessment of the impulse noise attenuation by earplugs in metalworking processes]. / Ocena ograniczania halasu impulsowego przez wkladki przeciwhalasowe podczas obróbki metalu.

BACKGROUND: The aim of the study was to answer the question of whether earplugs provide sufficient protection in the exposure to impulse noise generated during metalworking processes. MATERIAL AND METHODS: The noise generated by die forging hammer and punching machine was characterized. Using an acoustic test fixture, noise parameters (LCpeak, LAmax) under 24 earplugs, foam, winged and no-roll, were measured. Octave band method was used to calculate values of LAeq under earplugs. RESULTS: It was found that in the case of punching machine the exposure limit value of A-weighted noise exposure level, normalized to an 8-h working day (LEX, 8h = 94.8 dB) of noise present at the workstation, was exceeded, while in the case of die forging hammer both the exposure limit value of this parameter (LEX, 8h = 108.3 dB) and the exposure limit value of peak sound pressure level (LCpeak = 148.9 dB) were exceeded. The assessment of noise parameters (LCpeak, LAmax, LAeq) under earplugs revealed that the noise attenuation can be insufficient, sufficient, or too high. CONCLUSIONS: Earplugs can be suitable hearing protection devices in metalworking processes. Of the 24 earplugs included in this study, 9 provided appropriate noise attenuation in the case of tested die forging hammer and 10 in the case of tested punching machine.

Assessment of exposure to voices and noise via earphones in manufacturing industry workers in Japan.

OBJECTIVES: There is concern that sound via earphones and headphones attached to headsets used in workplaces may be a risk factor for noise-induced hearing loss (NIHL). Although there are some previous studies investigating exposure to noise from headphones, almost none have assessed the risks to workers who use earphones. We assessed exposure to noise among workers who regularly wear earphones in noisy workplaces. METHODS: The subjects of this study were 21 workers who regularly wear earphones in three manufacturing companies in Japan. The sound pressure output from earphones and personal exposure to occupational noise was measured for each worker. A noise-dosimeter was used to measure individual exposure to occupational noise. The sound pressure output from the earphones was measured by recording the electric signal with a data recorder attached to the earphones, and the recording was analyzed by playing it back in the laboratory through a sound analyzer via an ear simulator. RESULTS: The mean scores for personal exposure and earphone output LAeq were 87.9 dB and 87.6 dB, respectively. Earphone output LAeq exceeded 85 dB for two-thirds of the subjects. Nearly all the subjects lacked hearing protection devices (HPDs) on their earphones. CONCLUSIONS: The results suggest that workers who use earphones in noisy workplaces are exposed to the following NIHL risk factors: (1) they are deprived of the opportunity to fit appropriate HPDs, and (2) the sound pressure output from the earphones themselves exceeds the occupational exposure limit.