[A study on the hearing protection and intervention effects of silicone earplug usage among manufacturing workers].

Objective: To assess the efficacy of silicone earplugs in protecting workers exposed to noise in a typical manufacturing environment, and to provide training interventions for workers who do not achieve the anticipated noise reduction levels, as well as examining the spectral characteristics of earplug attenuation. Methods: From June to August 2022, a total of 294 noise-exposed workers in two manufacturing enterprises equipped with the same type of earplug were studied by cluster sampling method, by conducting questionnaire surveys, collecting data, fitting tests, and providing trainings, the current noise exposure levels of workers in the industry as well as the perception about the earplug were understood. Additionally, the attenuation before and after intervention in workplace were measured, the spectral characteristics of noise reduction were were described and compared. Results: The percentage of workers with Personal Attenuation Rating (PAR) of 0 is 32.7% (96/294), and the baseline pass rates are all below 60%. There were no significant differences in pass rates based on gender, age, noise exposure, education level, or cognition of earplug effectiveness. After adjusting the way that earplugs are worn or changing the type of earplugs, all workers were able to meet their noise reduction requirements. The median PAR improvement for both companies is above 10 dB. The noise attenuation of the earplug vary with frequency, with lower attenuation at 4 000 Hz and higher attenuation at 8 000 Hz, showing some deviation from the nominal values. Conclusion: The difference between the actual sound attenuation value of earplugs and the nominal value is related to the noise frequency. When using silicone earplugs, attention should be paid to the spectral composition of the noise in the workplace.

Music to Define a Generation: Factors Associated With Hearing Protection Use at Music Venues.

OBJECTIVES: Excessive noise levels in music venues can negatively impact long-term hearing health. We investigated the prevalence, characteristics, and factors associated with hearing protection use among music event attendees. STUDY DESIGN: Cross-sectional cohort. METHODS: Adult participants (2,352) from online music forums completed a questionnaire assessing attendance at music events, hearing protection (HP) usage, type, and frequency, along with history of hearing-related symptoms and medical history. Primary outcome was defined as HP use at music venues. Data were characterized using descriptive statistics, paired t tests, and Pearson's chi-squared tests. Multivariable regression analysis elicited factors associated with any and regular HP use. RESULTS: Our 2,352 respondents were primarily male (61.3%) and on average 28.7 years old (SD = 7.0). Of the respondents, 60.6% reported using HP, and 33.2% reported regular use; high-fidelity earplugs were the most used HP type (57.5%). HP use was associated with significantly fewer reports of negative hearing-related symptoms. In a multivariable regression model, factors associated with less likelihood of HP use included being female (vs male, OR = 0.74, CI = [0.55-0.98]), less concern about effects on hearing (OR = 0.53, CI = [0.45-0.61]), and pop music event attendance (vs EDM, OR = 0.40, CI = [0.22-0.72]). Increased attendance frequency in the past year was associated with higher likelihood of regular HP use (OR = 1.07, CI = [1.04-1.09]). Decreased attendance duration was associated with decreased likelihood (OR = 0.09, CI = [0.03-0.33]). CONCLUSION: HP use prevalence was high, while frequent use remained low. HP use was significantly associated with reduced hearing-related symptoms. Demographic factors, otologic symp-tomology, and attendance-related characteristics were associated with HP use. These findings may guide interventions to increase adoption at music venues. LEVEL OF EVIDENCE: 4.

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.

The Impact of Earplugs and Eye Masks on Sleep Quality in Surgical ICU Patients at Risk for Frequent Awakenings.

OBJECTIVES: Sleep disturbances may contribute to the development of delirium, prolonged ICU stay, and increased mortality. There is conflicting data on the effectiveness of earplugs and eye masks for sleep promotion in the ICU. This study evaluates the impact of earplugs and eye masks on sleep quality in postoperative surgical ICU patients at risk for frequent awakenings. DESIGN: Prospective randomized controlled trial. SETTING: Surgical ICU within the University of Texas Southwestern Medical Center. PATIENTS: Adult, female patients admitted to the surgical ICU requiring hourly postoperative assessments following breast free flap surgery between February 2018 and October 2019. INTERVENTIONS: Patients were randomized into an intervention group or a control group. The intervention group received earplugs and eye masks in addition to standard postoperative care, whereas the control group received standard postoperative care. MEASUREMENTS AND MAIN RESULTS: The primary outcome was overall sleep quality assessed via the Richards-Campbell Sleep Questionnaire. Secondary outcomes of patient satisfaction and rates of ICU delirium were assessed with a modified version of the Family Satisfaction in the ICU survey and the Confusion Assessment Method for the ICU. After a planned interim analysis, the study was stopped early because prespecified criteria for significance were attained. Compared with the control group's average Richards-Campbell Sleep Questionnaire total score of 47.3 (95% CI, 40.8-53.8), the intervention group's average Richards-Campbell Sleep Questionnaire total score was significantly higher at 64.5 (95% CI, 58.3-70.7; p = 0.0007). There were no significant between-group differences for Confusion Assessment Method for the ICU scores or modified Family Satisfaction in the ICU survey scores. CONCLUSIONS: These results suggest that earplugs and eye masks are effective in improving sleep quality in ICU patients undergoing frequent assessments. The results strengthen the evidence for nonpharmacologic sleep-promoting adjuncts in the ICU.

Associations between adolescents' earphone usage in noisy environments, hearing loss, and self-reported hearing problems in a nationally representative sample of South Korean middle and high school students.

ABSTRACT: Few epidemiological studies have examined the relationship between earphone usage and hearing loss in adolescents. This study identified the prevalence of hearing loss in South Korean adolescents using representative national survey data and evaluated the relationship between earphone usage in a noisy environment and hearing loss. This study analyzed 532 subjects (12-19 years) who participated in a 2012 national survey and completed health and noise environment exposure questionnaires and pure tone audiometry (PTA) test. Hearing loss was defined as an average hearing threshold of 26 Decibel-A (dBA) or higher in PTA. The relationship between earphone usage and hearing loss was analyzed using a hierarchical logistic regression model. Adolescents who were exposed to high noise levels via headphones in a noisy environment had a hearing loss prevalence of 22.6% and adolescents who used earphones 80 minutes or more per day on average had the hearing loss prevalence of 22.3%. The results of the logistic regression analysis revealed that adolescents who used earphones in a noisy environment had a 4.5-fold higher risk of hearing loss and an 8.4 times higher risk of having a subjective hearing problem than those who did not use earphones (prevalence odds ratio (pOR) = 4.54, 95% confidence interval (CI): 1.35-15.24; pOR = 8.39, 95% CI: 1.12-62.83, respectively). Additionally, adolescents who used earphones more than 80 minutes per day in a noisy environment had a 4.7 times higher risk of hearing loss than those who used them less than 80 minutes per day (pOR = 4.68, 95% CI: 1.08-20.22). Longitudinal studies are needed to provide evidence of causality between earphone usage and hearing loss.

Survey of Teen Noise Exposure and Efforts to Protect Hearing at School - United States, 2020.

Noise-induced hearing loss (NIHL) is a substantial, often unrecognized, health problem. Various learning environments and activities in school settings are loud. Researchers have reported the prevalence of NIHL among U.S. adolescents ranging between 12.8% and 17.5%, suggesting that one in every six to eight middle and high school students (aged 12-19 years) has measurable hearing loss likely resulting from excessive noise exposure (1). Evidence suggests that even mild levels of hearing loss negatively affect auditory perception and cognitive skills.* CDC analyzed data from a sample of 817 youths aged 12-17 years who responded to the web-based YouthStyles survey in 2020. The survey measured the frequency of exposure to loud noise in school settings, the provision of hearing protection devices (HPDs) during exposure, and whether prevention techniques were part of their educational curriculum. Approximately three in four teenage students reported being exposed to loud sound at school, and nearly one half (46.5%) of respondents reported exposure to loud sounds at school on a regular basis. A majority of students (85.9%) reported that their school did not provide HPDs during classes or activities where they were exposed to loud sounds, and seven out of 10 reported they were never taught how to protect their hearing. Increasing youth's awareness about the adverse health effects of excessive noise exposure and simple preventive measures to reduce risk can help prevent or reduce NIHL. Health care providers and educators have resources and tools available to prevent NIHL among school-aged children. Increased efforts are needed to promote prevention.

Ultra-broadband local active noise control with remote acoustic sensing.

One enduring challenge for controlling high frequency sound in local active noise control (ANC) systems is to obtain the acoustic signal at the specific location to be controlled. In some applications such as in ANC headrest systems, it is not practical to install error microphones in a person's ears to provide the user a quiet or optimally acoustically controlled environment. Many virtual error sensing approaches have been proposed to estimate the acoustic signal remotely with the current state-of-the-art method using an array of four microphones and a head tracking system to yield sound reduction up to 1 kHz for a single sound source. In the work reported in this paper, a novel approach of incorporating remote acoustic sensing using a laser Doppler vibrometer into an ANC headrest system is investigated. In this "virtual ANC headphone" system, a lightweight retro-reflective membrane pick-up is mounted in each synthetic ear of a head and torso simulator to determine the sound in the ear in real-time with minimal invasiveness. The membrane design and the effects of its location on the system performance are explored, the noise spectra in the ears without and with ANC for a variety of relevant primary sound fields are reported, and the performance of the system during head movements is demonstrated. The test results show that at least 10 dB sound attenuation can be realised in the ears over an extended frequency range (from 500 Hz to 6 kHz) under a complex sound field and for several common types of synthesised environmental noise, even in the presence of head motion.

Community-based program to increase use of hearing conservation practices among farm and rural youth: a cluster randomized trial of effectiveness.

BACKGROUND: Noise exposure and associated hearing loss affects an estimated 2 million farm youth who are exposed as farm residents, farm family workers, hired workers, children of migrant or seasonal workers, and farm visitors. Risk factors for farm youth include frequent exposure to high farm noise; farm work from an early age, and exposure to high recreational noise (e.g., firearms, ATVs, and personal listening devices). METHODS: This study compared the effectiveness of two interventions and control. The programs included a community-based interactive youth educational program alone (Group A), a community-based interactive youth educational program followed by an Internet-based booster (Group B), and a no-interaction control (Group C). The study used a cluster randomized control design, with equal allocation ratio to each cluster, without blinding. Inclusion criteria included enrollment in grade 4, parental consent, English speaking, and attending a community-based educational event included in the cluster sampling. A total of 1979 youth were enrolled at 36 sites distributed across the 3 study arms in the following distribution: N = 662 in 13 sites (Group A), N = 680 in 12 sites (Group B), and N = 637 in 11 sites (Group C). RESULTS: Comparison with pre-intervention data showed no difference in intent to use hearing conservation strategies in experimental groups. However, knowledge and attitudes toward hearing conservation were improved in the groups receiving the Internet-based booster. Participants reported frequent exposure to sources of hazardous noise (e.g., loud sporting events, firecrackers, personal listening devices). CONCLUSIONS: It is feasible and acceptable to incorporate hearing health education into an already existing system designed to deliver health and safety educational programming to farm and rural youth. The program was adopted by the partner agency for dissemination to up to 100,000 youth annually. Results of this study inform future intervention studies, interventions aimed at farm youth, and interventions to increase use of hearing conservation strategies, as well as offer a base for developing programs for non-English speaking children. TRIAL REGISTRATION: Clinicaltrials.gov registration CT02472821. Date of trial registration: 06/09/2015 (retrospectively registered).

The hearing function of sound engineers: A hearing conservation perspective.

BACKGROUND: Occupational activities performed by sound engineers are associated with hearing loss. However, there is a dearth of research on the hearing functions and the related hearing loss for sound engineers. OBJECTIVES: To determine the hearing function and early effects of noise on the hearing ability of sound engineers, and to establish whether there are hearing conservation programmes (HCPs) available for sound engineer participants in Johannesburg. METHODS: A quantitative cross-sectional design was used. Eight sound engineers from the Academy of Sound Engineering (ASE) participated in the study. The following data were collected from the participants: case history data, ear-related symptoms and hearing conservation data. Hearing screening followed by full diagnostic audiological assessments was conducted for each participant. Descriptive statistics and one-sample t-test were used to analyse the data (confidence interval [CI] = 95%). RESULTS: Participants reported tinnitus and aural fullness as common complaints. Only one participant had a unilateral impacted cerumen. All the participants presented with hearing within normal limits bilaterally, with a percentage loss of hearing (PLH) of 1.1% for all the participants. However, five participants presented with a notched configuration that was ≥ 10 decibel (dB), in the high frequency region at 3000 Hz and 6000 Hz bilaterally. One-sample t-test (p = 0.001) inferred that at a mean age of 27.6 years (standard deviation [SD] = 3.85), a notch at 3000 Hz and 6000 Hz was associated with an early sign of a hearing loss for the study participants. An HCP was not in place at the study site. CONCLUSION: The study indicated a younger age as an associated early sign of noise-induced hearing loss (NIHL) for the study participants, and that audiologists' clinical practice needs to explore HCP strategies specific for the sound engineers in order to prevent hearing loss.

Development and application of a noise-hazard scheme for road maintainers.

BACKGROUND: Transportation road maintenance and repair workers, or "maintainers," are exposed to hazardous and variable noise levels and often rely on hearing protection devices (HPD) to reduce noise-exposure levels. We aimed to improve upon HPD use as part of the HearWell program that used a Total Worker Health, participatory approach to hearing conservation. METHODS: Full-shift, personal noise sampling was performed during the routine task of brush cutting. Work activities and equipment were recorded and combined with 1-min noise measures to summarize personal noise-exposure levels by equipment. Using noise-monitoring results, HPD noise reduction ratings, and input from worker-based design teams, a noise-hazard scheme was developed and applied to the task and equipment used during brush cutting. RESULTS: Average (standard deviation) and maximum Leq 1-minute, personal noise-exposure levels recorded during brush cutting included chainsaws at 92.1 (7.6) and max of 111 dBA, leaf blowers at 91.2 (7.5) and max 107 dBA, and wood chipper at 90.3 (7.3) and max of 104 dBA. The worker-designed noise-hazard scheme breaks down noise exposures into one of three color bands and exposure ranges: red (over 105 dBA), orange (90-105 dBA), or yellow (85-90 dBA). The scheme simplifies the identification of noise levels, assessment of noise-hazard, and choice of appropriate hearing protection for workers. CONCLUSION: Combining noise-exposure assessment with intervention development using participatory methods, we characterized noise exposure and developed an intervention to educate and assist in protecting workers as they perform noisy tasks.

A pilot survey of Southeastern firefighters: Safety practices, use of protective gear, and injury.

INTRO: There were over 60 firefighter line of duty deaths and roughly 30,000 injuries in the United States in 2016. Modern thermoprotective gear has reduced the risks firefighters face from both thermal and inhalation injury, but must be used properly to be effective. The purpose of this study is to examine gear use and associated injury in firefighters. METHODS: Surveys were distributed with questions about demographics, gear usage, and maintenance practices. If previously injured, firefighters described the injury, treatment, and recovery. RESULTS: Of the 50 surveys distributed, 37 were returned (72%). A majority of respondents (70%) reported wearing incomplete gear. Those who reported injury were more likely to have omitted gear (81% vs 45%). For all respondents, the items most commonly omitted were hood (58%), gloves (22%), and earflaps (22%). Regular cleaning of gear was not practiced by 39% of burned respondents and 46% had not had their gear sized within 2 years. Serious burns were reported by 41% of respondents. Mean burn size was 7% total body surface area (TBSA), and 11% reported self-treating their burns, including 63.5% who continued to work despite suffering a 2nd or 3rd degree burn injury. Only 17% were treated at a burn center, and this group missed anywhere from two shifts to 8 months of work. CONCLUSIONS: Firefighters risk injury by omitting gear and not adhering to National Fire Protection Association (NFPA) guidelines on gear sizing, maintenance, and station wear. Firefighters also frequently self-treat serious burns despite unique considerations regarding re-injury. National trends related to gear use and injury risk should be studied further, and standards should be developed for ensuring safe return to work.

Epidemiology and gender differences in pediatric recreational and firearms noise exposure in the USA.

OBJECTIVE: We aim to identify contemporary noise exposures and hearing protection use among U.S. children in a large, population-based study. METHODS: Cross-sectional analysis of the 2014 National Health Interview Series was performed. Results from in-person interviews of families with children under 18 years of age in all 50 states were queried. Potentially harmful exposures to loud sounds and patterns of hearing protection use in the last 12 months were analyzed after representative sample weights were applied. RESULTS: Among 73.4 million children, 18.4% (9.1 ± 0.4 million) (boys: 23.2%, girls: 13.5%; P < 0.001) were exposed to firearms noise, and 28.2% (20.7 ± 0.6 million) (boys: 30.5%, girls: 25.8%; P < 0.001) to firecrackers and other explosive sounds. Exposure to recreational "very-loud" noise exposure was more common (7.9%; 5.8 ± 0.3 million), consisting of music players (46.5%), fireworks (44.8%), lawnmowers (42.6%), and firearms (32.5%). However, only 17.1% of boys and 15.6% of girls, totaling 16.4% of all children, always used hearing protection during noise exposures. CONCLUSION: Children in the United States are commonly exposed to firearms and recreational loud noises. Hearing protection is infrequently used, and gender disparities in patterns of exposure and use of hearing protection are prevalent. Those children and families at risk should be identified via public health initiatives and appropriately counseled by healthcare providers. LEVEL OF EVIDENCE: NA Laryngoscope, 130:541-545, 2020.

Cochrane corner: interventions to prevent hearing loss caused by noise at work.

This Cochrane Corner features "Interventions to prevent hearing loss caused by noise at work", published in 2017. The aim of this Cochrane Review was to find out if hearing loss caused by noise at work is being prevented by current interventions. Tikka et al. identified 29 studies that studied the effect of preventive measures. One study evaluated legislation to reduce noise exposure, eleven studies evaluated effects of personal hearing protection devices and 17 studies evaluated effects of hearing loss prevention programmes (HLPPs). There was some very low-quality evidence that implementation of stricter legislation can reduce noise levels in workplaces and moderate-quality evidence that training of proper insertion of earplugs significantly reduces noise exposure at short-term follow-up. This Cochrane review has identified specific strategies that have shown effectiveness in reducing workplace noise, such as the implementation of stricter legislation and the need for training in the proper use of earplugs and earmuffs to reduce noise exposure to safe levels. The overall quality of evidence for the effectiveness of HLPPs in preventing hearing loss was very low, there was limited follow-up of participants receiving training for insertion of earplugs and no controlled studies examining engineering controls to reduce workplace noise.

Hearing loss among military personnel in relation to occupational and leisure noise exposure and usage of personal protective equipment.

CONTEXT: Hearing loss (HL) is a major health concern among military personnel due to noise from shooting, blasts, military vehicles, and noisy training environments. Nevertheless, one's exposure can be partially reduced by using personal protective equipment (PPE). The aim of this study is to estimate the prevalence of HL among military personnel, to analyse associations between HL and self-reported occupational and leisure noise exposure, and use of PPEs. MATERIALS AND METHODS: A cross-sectional study was conducted among 150 military personnel during their routine medical examinations. First, all participants filled in a questionnaire about their exposure to noise and later the respondents went through an audiometric test. The diagnostic criteria for slight, moderate, and severe HL was HL of 25-40, 41-60, and >60 dB at 4 and 6 kHz, respectively. The associations between noise exposure and HL were studied with multinomial logistic regression analysis. RESULTS: The prevalence of slight to severe HL in high frequencies (4 and 6 kHz) among study participants was 62.7%. Nevertheless, the majority of it was slight, as the prevalence of severe HL was 9.3%. The prevalence of any kind of HL was highest in the Navy and the prevalence of severe HL was highest in the Central Command Units. The relative risk ratios (RRRs) for HL were higher among those who had been working for a long time in a noisy environment, working with noise-producing equipment, driving in a PASI or a Bandvagn or had been shooting with blanks at least once per week. It also appeared that military personnel who had HL, reported tinnitus more often. Respondents' previous health problems, music-listening habits, and amount of exposure to loud noise in non-military environments were not independently associated with HL, but in several cases it increased the RRRs together with military exposure. We also found significantly more frequent HL among those never using PPEs. CONCLUSION: HL loss was more prevalent among personnel who are more often exposed to military noise, especially among those who never use PPEs. The effect was enhanced by leisure time noise, but it was not independently associated to HL.

Noise exposures and perceptions of hearing conservation programs among wildland firefighters.

Wildland firefighters are exposed to numerous noise sources that may be hazardous to their hearing. This study examined the noise exposure profiles for 264 wildland firefighters across 15 job categories. All 264 firefighters completed questionnaires to assess their use of hearing protection devices, enrollment in hearing conservation programs, and their overall perception of their noise exposure. Roughly 54% of firefighters' noise exposures exceeded the National Institute for Occupational Safety and Health recommended exposure limit of 85 decibels, A-weighted, over 8 hr, and 32% exceeded the Occupational Safety and Health Administration permissible exposure limit of 90 decibels, A-weighted, over 8 hr. Questionnaire results indicated good agreement between noise exposures and firefighters' perceptions of the noise hazard. Approximately 65% reported that they used some form of hearing protection; however, only 19% reported receiving any proper training regarding the use of hearing protection devices, with the majority of those firefighters relying on earplugs, including electronic and level-dependent earplugs, over earmuffs or other forms of hearing protectors. The results also suggest that improved communication and situational awareness play a greater role in the consistent use of hearing protection devices than other factors such as risk of developing noise-induced hearing loss. The study highlighted the challenges facing wildland firefighters and their management and the need for a comprehensive wildland fire agencies' hearing conservation program especially for firefighters who were exempt based on their occupational designations.

Prevalence and determinants of noise-induced hearing loss among workers in the automotive industry in China: A pilot study.

OBJECTIVE: Data on noise-induced hearing loss (NIHL) in the automotive industry are rare. This pilot study aimed to investigate the prevalence and determinants of NIHL among workers in the automotive industry in China. METHODS: A cross-sectional survey was conducted with 6557 participants from the automotive industry. The questionnaire survey was administered, and individual noise exposure level (LAeq.8h ) and hearing loss level were measured. RESULTS: Of participants, 96.43% were male; the median age was 27.0 years and 28.82% had NIHL defined as adjusted high-frequency noise-induced hearing loss (AHFNIHL). Concerning individual noise levels (LAeq.8h ), 62.53% exceeded 85 dB(A), which were mainly concentrated in various jobs, including metal cutting, surface treatment, stamping, welding, grinding, assembly, plastic molding, and forging. Each typical noise source generated its own unique temporal waveform shape with the type of non-Gaussian noise. Of workers, 53.15% regularly used hearing protector devices (HPD), and the proportion of regular HPD use increased with LAeq.8h . The trend test showed that the prevalence of AHFNIHL in male workers significantly increased with an increase in LAeq.8h at <94 dB(A) and cumulative noise exposure (CNE) in each age group (P < 0.05 or P < 0.01). A logistic regression analysis showed that CNE and HPD usage frequency were important factors contributing to AHFNIHL. CONCLUSIONS: CNE and HPD usage frequency were the determinants for NIHL. Much more human surveys are needed to understand the prevalence and determinants of NIHL in the automotive industry in China.

Safety climate, hearing climate and hearing protection device use among transportation road maintainers.

BACKGROUND: It is important to understand workplace factors including safety climate that influence hearing protection device (HPD) use. We sought to investigate the association between HPD use, safety climate, and hearing climate, a new measure specific to hearing. METHODS: A survey was developed and distributed among transportation "maintainers" who perform road maintenance and repair. A new hearing climate measure was designed by adapting a safety climate measure. HPD use was assessed by asking workers how often they wear HPD while in noise. The differences in safety climate and hearing climate were compared by the frequency of HPD use using analysis of variance. RESULTS: Among 166 maintainers, 54% reported always or almost always wearing HPD while noise exposed. High-frequency HPD users reported a statistically significant higher safety climate (P = 0.004) and hearing climate (P = 0.003). CONCLUSIONS: Hearing climate predicts the frequency of HPD use and may be a useful measure when assessing and improving hearing conservation programs.

Validation of clinical techniques for verification of uniform attenuation earplugs.

OBJECTIVE: Uniform attenuation earplugs (UAE) theoretically provide near even attenuation across frequencies when built to a manufacturer's specifications. Unfortunately, there is no current research available confirming if custom-molded uniform attenuation earplugs (UAE) are made to specifications nor is there guidance available on clinical methods of measuring attenuation of uniform attenuation earplug (UAE) devices. The goal of this study was to evaluate different procedures for UAE verification and to determine the most accurate clinically accessible verification protocol. DESIGN: Attenuation was measured using probe microphone techniques, as well as real-ear attenuation at threshold (REAT) measurements under circumaural earphones, soundfield speakers and supra-aural earphones. Comparisons were made to a reference system created in the laboratory. STUDY SAMPLE: Seventeen adult participants, totaling 30 ears. RESULTS: The results of this study demonstrate that the REAT measured in the soundfield using a narrowband noise stimulus with masking in the contralateral ear is currently the most accurate and widely available method of verifying UAEs. CONCLUSIONS: Factoring in clinical efficiency, the authors of this study recommend verifying attenuation levels using a soundfield REAT procedure as best clinical practice. In addition, the data suggests that REAT measurements under circumaural earphones are an acceptable second choice method.

Occupational noise exposure and hearing defects among sawmill workers in the south of Thailand.

The aim of this study was to investigate occupational noise exposure and hearing defects among sawmill workers in the south of Thailand. Seven hundred sawmill workers participated, of which 335 (47.9%) were male. The mean age of the sawmill workers was 33.5 years (SD 10.2), and more than 60% were <35 years old; 75.1% of the workers had less than 5 years of work experience. Only about one in four workers (25%) had been trained in use of personal protective equipment (PPE), and half of the participants never or rarely wore PPE while working. The prevalence rate of noise-induced hearing loss (NIHL) was 22.8% (N = 42). Male workers had significantly higher risk than female workers (odds ratio [OR] = 2.21). Workers aged older than 25 years had significantly higher risks for NIHL (OR = 3.51-12.42) than workers younger than 25 years. Sawing workers had higher risk for NIHL than office workers (OR = 3.07).

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.