Noise-induced hearing loss and hearing protection: Attitudes at a South African coal mine

BACKGROUND

 Negative attitudes and beliefs are major contributing factors to the rising numbers of noise-induced hearing loss (NIHL) cases in coal mines both locally and internationally. International literature confirms limited knowledge surrounding employees' attitudes and beliefs regarding NIHL and hearing protection devices (HPDs), hence the need for the study.

OBJECTIVES

 To ascertain the attitudes and beliefs about NIHL and HPD use among employees at a large scale underground coal mine in Mpumalanga.

METHOD

 A descriptive and exploratory cross-sectional study was conducted using a self-administered questionnaire, developed by the National Institute for Occupational Safety and Health (NIOSH) on Beliefs about Hearing Protection and Hearing Loss (BHPHL). Participants (n = 241) included employees from a coal mine in Mpumalanga, South Africa.

RESULTS

 Out of 241 completed surveys, this study found that 84% were aware of when to replace earmuffs; 95% believed wearing HPDs could prevent hearing loss in noisy environments; 83% felt their hearing was impacted by loud noise. Additionally, 86% mentioned discomfort from earmuff pressure; 95% emphasised HPD importance; and 95% used HPDs around loud sounds. Moreover, 98% knew how to properly wear earplugs, while lower education levels were linked to higher susceptibility to NIHL.

CONCLUSION

 The study identified positive attitudes towards NIHL and HPD use, but existing NIHL cases must be acknowledged. Organisations can use the findings to develop tailored hearing conservation programmes (HCP), including education, involving employees in protection decisions and promoting diligent HPD usage.Contribution: This study contributes to the limited literature on noise perceptions, NIHL, and HPD use in mining, emphasising the impact attitude has on HPD use and assessing the effect of miners NIHL knowledge on compliance. The findings, unique to coal mining, hold significance for enhancing hearing conservation and reducing NIHL.

Perforated Concave Earplug (pCEP): A Proof-of-Concept Earplug to Improve Sound Localization without Compromising Noise Attenuation

Combat soldiers are currently faced with using a hearing-protection device (HPD) at the cost of adequately detecting critical signals impacting mission success. The current study tested the performance of the Perforated-Concave-Earplug (pCEP), a proof-of-concept passive HPD consisting of a concave bowl-like rigid structure attached to a commercial roll-down earplug, designed to improve sound localization with minimal compromising of noise attenuation. Primarily intended for combat/military training settings, our aim was an evaluation of localization of relevant sound sources (single/multiple gunfire, continuous noise, spoken word) compared to 3M™-Combat-Arms™4.1 earplugs in open-mode and 3M™-E-A-R™-Classic™ earplugs. Ninety normal-hearing participants, aged 20-35 years, were asked to localize stimuli delivered from monitors evenly distributed around them in no-HPD and with-HPD conditions. The results showed (1) localization abilities worsened using HPDs; (2) the spoken word was localized less accurately than other stimuli; (3) mean root mean square errors (RMSEs) were largest for stimuli emanating from rear monitors; and (4) localization abilities corresponded to HPD attenuation levels (largest attenuation and mean RMSE: 3M™-E-A-R™-Classic™; smallest attenuation and mean RMSE: 3M™-Combat-Arms™4.1; pCEP was mid-range on both). These findings suggest that the pCEP may benefit in military settings by providing improved sound localization relative to 3M™ E-A-R™-Classic™ and higher attenuation relative to 3M™-Combat Arms™-4.1, recommending its use in noisy environments.

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.

Prevalence of Hearing Loss and Perceptions of Hearing Health and Protection among Florida Firefighters

Firefighters are exposed to extensive hazardous noise while on the job, both during routine tasks at the station and when responding to calls. However, little is known about firefighters' occupational noise hazards. This study employed mixed methods, including focus groups, a survey, and audiometric testing, to identify sources of noise in the firefighters' work environment, determine hearing protective strategies, discern firefighters' perceptions of occupational noise exposure and impacts to their health, and quantify the prevalence of hearing loss among South Florida firefighters. A total of 6 senior officers served in an expert panel, 12 participated in focus groups, 300 completed the survey, and 214 received audiometric tests. Most firefighters were unaware of the risk and their departments' policies, and did not participate in hearing protection practices and avoided using hearing protection devices, which they believed impede team communication and situational awareness. Nearly 30% of participating firefighters showed mild to profound hearing loss, a prevalence that is considerably worse than expected by normal aging alone. Educating firefighters about noise-induced hearing loss early in their careers may have significant health implications for their future. These findings provide insights for developing technologies and programs to mitigate the effects of noise exposure in the firefighting population.

Relationship between risk perception toward hearing conservation and using hearing protection devices among offset printing workers in Tehran province, Iran

The way workers perceive noise exposure can play an important role in the adoption of safety behaviors. Therefore, the determination of the relationship among risk awareness, behavior, and exposure can be an extremely important issue in controlling noise exposure. The aim of this study was to investigate the association between risk perception and practice of workers. Workers from 16 printing houses in Tehran province participated in present study. A questionnaire was used for determining the level of risk perception and practice about hearing conservation. The results revealed a significant relationship between risk perception and safety behavior adoption (P < 0.001). A positive and significant correlation was found between these two variables (P < 0.001; r_s = 0.912). Also, the results showed that workers with hearing impairment had a better practice. In addition, attention should be paid to preventive principles and encouragement of hearing protection devices usage among employees.

The study of attenuation levels and the comfort of earplugs

Introduction:

This study aimed to analyze and compare four different types of earplugs, divided into premolded plugs and foam plug models, in relation to the level of attenuation, comfort, and the size of the external acoustic meatus (EAM) in an attempt to identify how these variables influence the choice of specific hearing protection devices (HPDs).

Materials and Methods:

A cross-sectional observational study was performed in a sample of 49 participants, oriented toward the ideal placement of four HPDs, two premolded and two foam plugs (3M™). The procedures included otoscopy, EAM diameter measurement using an otometer, EAM volume measurement via an acoustic impedance test, and the obtainment of the bilateral personal attenuation rating (PAR) for each HPD using the E-A-Rfit™ Validation System (3M™). The Bipolar Comfort Rating Scale (BCRS) instrument was applied twice for each individual: once after the evaluations with the premolded HPDs and again after the evaluations with the foam plug HPDs. Then, each participant was asked which was his/her favorite protector.

Results:

The volume of the EAM was not directly related to the diameter of the EAM. The attenuation did not interfere with the HPD preference, and the PAR of the foam plug was significantly higher regardless of the preferred HPD. Regarding the BCRS, the variables “Placement,” “Complexity,” and “Occlusion Effect” had higher scores for premolded HPDs and had a direct relationship with the type of preferred HPD.

Conclusion:

Attention to the use of HPDs should be personalized, taking into account the needs of each individual, considering not only the attenuation, but also the user’s reported well-being.

Occupational noise exposure and hearing loss: A study of knowledge, attitude and practice among Tanzanian iron and steel workers

We assessed Knowledge Attitude and Practice (KAP) regarding occupational noise exposure, Noise-induced hearing loss, audiometry and use of hearing protection devices among iron and steel factory workers exposed to high noise level. A modified, validated, structured questionnaire was used to collect information from 253 male workers randomly selected from the four factories. The sum scores for each domain of KAP were computed. Scores above 75% were defined as good knowledge and positive attitude. For practice, scores of >50% were defined as good. Independent samples t-test and Chi-squared test were used to analyze association between KAP and continuous/categorical variables respectively. Majority of workers displayed poor knowledge and poor practice (94%), but 76% displayed a positive attitude. Most of the workers (86%) had never been provided with hearing protection devices. The mean scores for attitude and practice differed significantly between the four factories (one-way ANOVA, p < 0.001). Implementation of hearing conservation program with provision of hearing protection devices are suggested.

Earmuff efficacy in the workplace using F-MIRE - a case report

PURPOSE

To determine the field efficacy of an earmuff used by the employees of a private company.

METHODS

Measurements were performed using a double-channel noise dosimeter. Noise levels collected in one-third-octave bands were corrected with the frequency response for diffuse sound field and attenuation was compared with values provided by the manufacturer of the hearing protection device (HPD).

RESULTS

Comparisons between the corrected noise reduction and the attenuation provided by the manufacturer of the HPD show no statistically significant differences in attenuation for most frequency bands, with higher mean values for the observed corrected noise reduction. However, despite the fact that the field attenuation values are above those obtained in the laboratory, when individual attenuation values were compared with expected attenuation values it was found that the employees have below-expected noise attenuation in all frequency bands.

CONCLUSIONS

The fact that over 60% of the employees had frequency band attenuations below that expected for most frequency bands underscores the need for individual assessment of attenuation provided by the HPD in the workplace, to assess whether the HPD is functional and what provisions should be implemented in a specific workplace.

Hearing protection devices: Use at work predicts use at play

Use of hearing protection devices (HPDs) at work is widespread and well researched, but less is known about HPD use in high-noise leisure activities. We investigated HPD use of 8,144 Australians in leisure settings. An online survey asked questions about HPD use at work and leisure and examined whether age, gender, HPD use at work, and tinnitus predicted HPD use in leisure activities. Leisure-based HPD use was most common during high-risk work-related activities. Use of HPDs at work was the most significant predictor of leisure-based use, with workplace users up to 5 times more likely to use HPDs at leisure. Men were significantly more likely than women to use HPDs in 10/20 leisure activities, and those with tinnitus were more likely than those without to use HPDs in 8/20 activities. Older participants were more likely to use HPDs at nightclubs and concerts, but younger participants were more likely to use HPDs playing e-games and musical instruments.

Measurement of impulse peak insertion loss for four hearing protection devices in field conditions

OBJECTIVE

In 2009, the U.S. Environmental Protection Agency (EPA) proposed an impulse noise reduction rating (NRR) for hearing protection devices based upon the impulse peak insertion loss (IPIL) methods in the ANSI S12.42-2010 standard. This study tests the ANSI S12.42 methods with a range of hearing protection devices measured in field conditions.

DESIGN

The method utilizes an acoustic test fixture and three ranges for impulse levels: 130-134, 148-152, and 166-170 dB peak SPL. For this study, four different models of hearing protectors were tested: Bilsom 707 Impact II electronic earmuff, E·A·R Pod Express, E·A·R Combat Arms version 4, and the Etymotic Research, Inc. Electronic BlastPLG™ EB1.

STUDY SAMPLE

Five samples of each protector were fitted on the fixture or inserted in the fixture's ear canal five times for each impulse level. Impulses were generated by a 0.223 caliber rifle.

RESULTS

The average IPILs increased with peak pressure and ranged between 20 and 38 dB. For some protectors, significant differences were observed across protector examples of the same model, and across insertions.

CONCLUSIONS

The EPA's proposed methods provide consistent and reproducible results. The proposed impulse NRR rating should utilize the minimum and maximum protection percentiles as determined by the ANSI S12.42-2010 methods.

Pilot survey of subway and bus stop noise levels

Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 +/- 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.