Nonoccupational Noise Exposure Research Articles

The National Institute for Occupational Safety and Health recommended exposure level for noise needs to be revised downwards

Noise-induced hearing loss (NIHL) is caused by cumulative occupational and non-occupational noise exposure. The National Institute for Occupational Safety and Health (NIOSH) developed recommendations for occupational noise exposure in 1972, revised in 1998. Fifty years after the NIOSH 85 dBA recommended exposure level (REL) was first published, it needs to be revised downwards. In its calculations, NIOSH assumed that workers have quiet (<60 dBA) when not at work, something no longer true. Everyday public noise exposure now exceeds the Environmental Protection Agency's safe noise level, a time-weighted average of 70 dB for 24 hours, with multiple studies reporting average exposures near 75 dBA. Also, NIOSH calculations were based on occupational studies of material hearing loss measured by limited frequency pure tone audiometry, an insensitive measure of noise-induced auditory damage. Modern audiology techniques include extended range audiometry, speech in noise testing, diffusion product otoacoustic emissions testing, and questions about tinnitus and hyperacusis. Doing the needed research to support downward REL revision, detecting auditory damage in noise-exposed workers with these newer techniques, is a daunting task, but this is necessary both to protect workers and because the NIOSH REL forms the basis for the world's recommendations for non-occupational noise exposure.

What is the safe noise level to prevent noise-induced hearing loss?

Noise causes short-term mechanical and chemical changes in the cochlea, transduced into electrical signals transmitted to the brain. Excessive noise exposure overwhelms the cochlea’s ability to reverse these changes, causing noise-induced hearing loss (NIHL). The Centers for Disease Control and Prevention state that NIHL is the only completely preventable type of hearing loss. What is the evidence-based safe noise exposure level to prevent NIHL? The National Institute for Occupational Safety and Health (NIOSH) recommended exposure level (REL), 85 dBA, does not prevent NIHL. Occupational exposures are calculated for 8 hours/day, 240 days/year, for 40 years. To calculate the noise exposure level to prevent NIHL in the public, 70 dB for 24 hours (Leq(24) = 70), the Environmental Protection Agency (EPA) adjusted the REL for 24 hours/day, 365 days/year exposure. The actual safe noise exposure must be lower than 70 dB because 1) the EPA did not adjust for lifetime noise exposure, 2) NIOSH based its REL on limited-frequency pure tone audiometry, an insensitive measure of auditory damage, and 3) non-occupational noise exposure has increased. The safe noise level may be as low as 55 dBA, the effective quiet level required for humans to recover from noise-induced temporary threshold shift.

A Comparison of Self-Reported Nonoccupational Noise Exposure in a Large Cohort of Listeners.

A variety of questionnaires have been developed to describe and quantify occupational and nonoccupational noise exposure, which are associated with hearing loss and tinnitus. The main aim of this study was to compare and contrast three commonly used nonoccupational noise exposure measurement questionnaires in a group of young adults. A total of 197 participants were recruited for this study. All the participants completed three commonly used nonoccupational noise exposure measurement questionnaires via Qualtrics software (Qualtrics, Provo, UT). General patterns in the nature of noise exposure were highlighted and statistical agreement and correlations between the three instruments were calculated. Comparisons were made between self-percept of noise exposure and annual noise exposure metrics obtained using questionnaires. Strong statistical agreement and correlation (r = 0.57, P < 0.001) was found between the selected instruments similar in their constructs of noise exposure. When compared to quantified scores of noise exposure, self-report of exposure to loud noise was highly sensitive but associated with poor specificity (3.61%) and a high false-positive rate (96.38%). The majority of participants reported exposure to noise from listening to music and attending loud recreational activities, with a differential effect of sex on average annual noise exposure values depending on the questionnaire used. The outcomes of this analysis could assist in comparing noise exposure quantifications across research studies, and determining if and how these questionnaires may be utilized clinically to effectively identify and counsel those at risk for noise-induced hearing loss.

Personal Audio Systems Unsafe At Any Sound

Personal Audio Systems Unsafe At Any Sound

Too Loud: Noise Exposure in Everyday Life is Causing Hearing Loss

Too Loud: Noise Exposure in Everyday Life is Causing Hearing Loss

Investigating the effects of occupational and environmental noise on cardiovascular diseases: a systematic review and meta-analysis.

The present study aimed to use a meta-analysis to investigate the relationship between occupational and non-occupational noise exposure expressed in various studies with cardiovascular disease. This is a systematic review and meta-analysis study based on PRISMA checklist. In this study, the researchers searched five international databases of Medline/PubMed, Embase, Scopus, ISI/web of knowledge, and Google Scholar. Search keywords included two categories noise and noise pollution, cardiovascular disease, and hypertension. The Joanna Briggs Institute checklist was used to review and control the quality of the articles. After all screening stage 139 articles entered the final analysis. The results show that except for East African environmental studies and workplace studies in East Asia, Western Asia, and Northern Europe, there was a significant association between noise exposure and cardiovascular disease. Also, there was a significant difference between the intensity of sound and blood pressure in workers (OR = 1.28, CI 95%: 1.15-1.42, P < 0.001). Based on the results of environmental noise, there was a significant difference between ambient noise intensity and blood pressure (OR = 1.55, CI 95%: 1.53-1.57, P < 0.001). It can be concluded that it is very important to study and identify jobs or living environments with less than the recommended noise level and in addition to hearing aids that occur in over-standard exposures, such as cardiovascular disease.

Associations between indoor temperature and noise and semen parameters among participants in the US-based general population Growing Up Today Study

BACKGROUND AND AIM: Multiple environmental exposures have been suggested as important determinants of decreases in semen quality. However, very little is known regarding the impacts of non-occupational noise and indoor temperature exposures. Our aim was to explore these associations in a general population cohort of young men in the United States. METHODS: Participants were members of the prospective Growing Up Today Study. Exposures to noise, temperature, and relative humidity were collected every 5 minutes for 90 days in the main room of each home with a NetAtmo weather station. Semen samples collected at home were sent by express shipping to the Massachusetts General Hospital Andrology Laboratory; sperm concentration and morphology were assessed via computer-aided and manual methods. Associations per interquartile range (IQR) were assessed in three-exposure generalized linear models, adjusted for age, race, and body mass index. RESULTS:The first 82 participants were included in analyses (average age 35.6 years). The average sperm concentration was 56.5 (SD=36.9) M/ml and the percent normal morphology was 4.5% (SD=2.1). The average 90-day average noise level was 62.5 dB (SD=8.0), temperature was 22.0°C (SD=1.9) and relative humidity was 54.0% (SD=8.2). There was little evidence that the exposures were associated with sperm concentration (-1.91, 95%CI:-12.44, 8.63 per 9.83dB of noise; -3.73, 95%CI: -14.93, 7.46 per 2.53°C; 9.25, 95%CI: -0.78, 19.27 per 9.63% relative humidity) or % normal morphology (0.04, 95%CI: -0.58, 0.66 per 9.83dB of noise; -0.59, 95%CI: -1.23, 0.05 per 2.53°C; 0.04, 95%CI: -0.53, 0.61 per 9.63% relative humidity). CONCLUSIONS:In this cohort of general population US men, temperature, humidity, and noise in the 90 days before producing a semen sample were not associated with measures of semen quality. The impact of these exposures may be limited to sensitive time windows. KEYWORDS: Noise, Temperature, Relative Humidity, Reproductive Outcomes, Male, environmental epidemiology

Non-occupational noise exposure in the United States: A review

That occupational noise exposure causes hearing loss has long been known, but non-occupational noise exposure was generally not recognized as causing hearing loss until the 1960s. Audiometric evaluation of populations not exposed to occupational noise was used to establish normal hearing baselines for workers compensation purposes. Audiometery in these groups, and in isolated populations not exposed to loud noise, suggested that hearing was preserved without noise exposure. The word sociocusis was used to describe non-occupational hearing loss. There are no federal recommendations, guidelines, or standards for non-occupational noise exposure. Perhaps because of a misconception that the 85 A-weighted decibel recommended occupational noise exposure limit is safe for the public without time limit, everyday noise exposure appears to have increased. Noise-induced hearing loss (NIHL) has become a major public health problem in the U.S., with approximately 20% of adolescents age 12–19 and 25% of adults age 20–69 having NIHL Common sources of non-occupational noise exposure include transportation noise, music and entertainment including personal listening devices, restaurant noise, kitchen appliances and power tools, hobbies, and sports. Efforts to reduce non-occupational noise exposure must include public education and the promulgation and enforcement of standards for non-occupational noise exposure.

Centers for Disease Control and Prevention non-occupational noise campaign

In February 2017, an intra-agency workgroup within the Centers for Disease Control and Prevention (CDC) National Center for Environmental Health (NCEH) launched a hearing loss campaign to increase awareness that excessive exposure to loud sounds outside of the working environment can lead to permanent noise-induced hearing loss (NIHL). The NCEH workgroup initiated research efforts and participated in activities to promote the prevention of NIHL from non-occupational noise exposures. This included the development of an online toolkit with infographics, videos, and other sharable media, several available in English and Spanish. Publication of CDC NIHL research has included peer-reviewed journals, partner articles and Morbidity and Mortality Weekly Report (MMWR) manuscripts. The CDC NIHL workgroup engages with various organizations and continues to analyze national data to prioritize public health needs in this area. CDC continues to develop communication materials, social media content, videos, and factsheets to support partners and other stakeholders. By providing evidence and education/health communication; through its partners CDC collaborates with other national efforts to increase awareness and behavioral change to prevent NIHL at home and in the community.

Improving our understanding on non-occupational noise-induced hearing loss

Noise is among the most common occupational and non-occupational exposures globally. As a result, the public health burden of noise-induced hearing loss is high. Some estimates suggest that roughly 20% of all hearing loss cases result from occupational noise exposure. Occupational noise exposures have been extensively studied and regulated in many countries for decades, and as a result the risk of occupational noise-induced hearing loss associated with different exposure levels and durations has been modeled and quantified. However, non-occupational exposures have not been nearly as well-characterized, and the risk of non-occupational noise-induced hearing loss is not well understood. This presentation will describe a systematic review conducted to evaluate the risk of noise-induced hearing loss associated with non-occupational noise. The presentation will also discuss knowledge gaps in our understanding of non-occupational noise exposures, and the need for tools to allow individuals to evaluate their own exposures against recommended non-occupational noise exposure limits, and ideally to share these “citizen-science” data for aggregated analysis. This approach is now being utilized in the Apple Hearing Study, a partnership between Apple, Inc., and the University of Michigan. Details will be provided on the research approaches and some preliminary results from the Apple Hearing Study.

Larry H. Royster memorial session

Larry Royster conducted pioneering research on the effectiveness of occupational hearing conservation programs, with a particular focus on the performance of hearing protection devices (HPDs) and audiometric database evaluation. Dr. Royster also conducted important early research into non-occupational noise exposures such as sporting events, recreational activities, and air travel. This presentation will briefly review key findings from Dr. Royster's work on these topics from the 1970s–1990s, and will then summarize the findings of a number of recent related studies. These will include: an evaluation of hearing conservation program effectiveness and hearing protector performance among aluminum manufacturing workers; an assessment of the contributions of occupational and non-occupational noise to hearing loss risk in a large sample of individuals in New York City; and a review of patterns and trends in occupational noise exposures in the US from 1979–2013. Collectively, these studies indicate that the risk of hearing loss from noise remains substantial among US workers, as well as in the general public that participates in noisy leisure-time activities, and highlight the importance of continuing the research that Dr. Royster started in order to protect the hearing health of Americans.

Early hearing slope as a predictor of subsequent hearing trajectory in a noise-exposed occupational cohort

Variations in individual susceptibility to noise-induced hearing loss have been observed among workers exposed to similar ambient noise levels but the reasons for this observation are poorly understood. Many workers are exposed to hazardous levels of occupational noise throughout their entire careers. Therefore, a mechanism to identify workers at risk for accelerated hearing loss early in their career may offer a time-sensitive window for targeted intervention. Using available longitudinal data for an occupationally noise-exposed cohort of manufacturing workers, this study aims to examine whether change in an individual's high frequency hearing level during the initial years of occupational noise exposure can predict subsequent high frequency hearing loss. General linear mixed modeling was used to model later hearing slope in the worse ear for the combined frequencies of 3, 4, and 6 kHz as a function of early hearing slope in the worse ear, age at baseline, sex, race/ethnicity, mean ambient workplace noise exposure, and self-reported non-occupational noise exposure. Those with accelerated early hearing loss were more likely to experience a greater rate of subsequent hearing loss, thus offering a potentially important opportunity for meaningful intervention among those at greatest risk of future hearing loss.

Association of organic solvents and occupational noise on hearing loss and tinnitus among adults in the U.S., 1999-2004.

Exposure to organic solvents and noise may be causal agents in the development of hearing loss and tinnitus. The objectives of the present study were to examine the association of organic solvents with hearing loss and tinnitus and to assess the interaction of organic solvent and occupational noise exposure on hearing loss and tinnitus. A secondary data analysis of data from the National Health and Nutrition Examination Survey and Occupational Information Network (O*NET) among a study population ranging from 1085 to 2471 study participants from 1999 to 2004. Multiple multivariate logistic regression models were used to assess the associations of individual organic solvent exposures as measured by blood biomarkers (1,4-dichlorobenzene, benzene, ethylbenzene, styrene, toluene, o-xylene, and m-/p-xylene) with self-reported hearing loss, audiometrically assessed hearing loss, and self-reported tinnitus. Models were adjusted for age, gender, race/ethnicity, diabetes, non-occupational noise exposure, smoking, and income. Organic solvents found to be statistically significantly associated with the outcome after adjusting for covariates were tested for interaction with occupational noise exposure. Solvent exposure was not statistically significantly associated with self-reported tinnitus. Benzene (OR 1.43, 95% CI 1.15-1.78), ethylbenzene (OR 1.24, 95% CI 1.02-1.50), and toluene (OR 1.27, 95% CI 1.06-1.52) concentrations were statistically significantly associated with increased adjusted odds of high-frequency hearing loss. No statistically significant interaction was observed between these solvents and occupational noise on high-frequency hearing loss. We found no evidence of an association between organic solvents and tinnitus; however, there was evidence of an association between organic solvent exposure and prevalence of high-frequency hearing loss.

Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers.

Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people’s livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen’s Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman’s ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

Mass Transit Ridership and Self-Reported Hearing Health in an Urban Population

Information on prevalence and risk factors associated with self-reported hearing health among mass transit riders is extremely limited, even though evidence suggests mass transit may be a source of excessive exposure to noise. Data on mass transit ridership were collected from 756 study participants using a self-administered questionnaire. Hearing health was measured using two symptom items (tinnitus and temporary audiometric threshold shift), two subjective measures (self-rated hearing and hearing ability), and two medical-related questions (hearing testing and physician-diagnosed hearing loss). In logistic regression analyses that controlled for possible confounders, including demographic variables, occupational noise exposure, nonoccupational noise exposure (including MP3 player use) and use of hearing protection, frequent and lengthy mass transit (all forms) ridership (1,100min or more per week vs. 350min or less per week) was the strongest predictor of temporary threshold shift symptoms. Noise abatement strategies, such as engineering controls, and the promotion of hearing protection use should be encouraged to reduce the risk of adverse impacts on the hearing health of mass transit users.

The influence of ambient noise and headphone style on listening volume using a personal stereo system

It is well known that exposure to excessive noise for long durations can cause a significant noise-induced hearing loss (NIHL). Although most research has focused on occupational sources of NIHL, there is growing concern about the potential damage caused by non-occupational noise exposure such as that from portable stereo system headphones. The purpose of current study was to measure the sound level generated by headphones of portable stereo system, and provide hearing conservation guidelines. Using a B&amp;K Torso and a personal computer, output sound levels across volume control set by thirty participants were measured from headphone driven by music samples of five different genres. Three different styles of headphones (in-ear, circum-aural, supra-aural) were used to determine if styles of headphone influence sound level inside of ears. The study results suggested that the supra-aural headphone used by listener in noisy environment shall set a higher volume, in a result of a larger sound level in eardrum. The authors would like to thank the Institute of Occupational Safety and Health of Taiwan for the support that made the completion of this work possible.

Typical noise exposure in daily life

Objective: Identify the distribution of typical noise levels present in daily life and identify factors associated with average sound levels. Design: This was an observational study. Study sample: Participants (N = 286) were 20 to 68 year old men and women, drawn from the general population of Kalamazoo County, Michigan. A total of 73 000 person-hours of noise monitoring were conducted. Results: Median overall daily average levels were 79 and 77 dBLeqA,8,equiv , with average levels exceeding EPA recommended levels for 70% of participants. Median levels were similar between the hours of 9 a.m. and 9 p.m., and varied little across days of the week. Gender, occupational classification, and history of occupational noise exposure were related to average noise levels, but age, educational attainment, and non-occupational noise exposures were not. Conclusions: A large portion of the general population is exposed to noise levels that could result in long-term adverse effects on hearing. Gender and occupation were most strongly related to exposure, though most participants in this study had occupations that are not conventionally considered noisy.

Assessment of Noise Exposure During Commuting in the Madrid Subway

Because noise-induced hearing impairment is the result not only of occupational noise exposure but also of total daily noise exposure, it is important to take the non-occupational exposure of individuals (during commuting to and from their jobs, at home, and during recreational activities) into account. Mass transit is one of the main contributors to non-occupational noise exposure. We developed a new methodology to estimate a representative commuting noise exposure. The methodology was put into practice for the Madrid subway because of all Spanish subway systems it covers the highest percentage of worker journeys (22.6%). The results of the application highlight that, for Madrid subway passengers, noise exposure level normalized to a nominal 8 hr (LEx,8h-cj ) depends strongly on the type of train, the presence of squealing noise, and the public address audio system, ranging from 68.6 dBA to 72.8 dBA. These values play an important role in a more complete evaluation of a relationship between noise dose and worker health response.

Auditory sensitivity in opiate addicts with and without a history of noise exposure

Several case reports suggest that some individuals are susceptible to hearing loss from opioids. A combination of noise and opium exposure is possible in either occupational setting such as military service or recreational settings. According to the Drug Enforcement Agency of the U.S. Department of Justice, prescriptions for opiate-based drugs have skyrocketed in the past decade. Since both opium and noise independently can cause hearing loss, it is important to know the prevalence of hearing loss among individuals who are exposed to opium or both opium and noise. The purpose of this research was to evaluate auditory sensitivity in individuals with a history of opium abuse and/or occupational or nonoccupational noise exposure. Twenty-three men who reported opiate abuse served as participants in the study. Four of the individuals reported no history of noise exposure, 12 reported hobby-related noise exposure, 7 reported occupational noise exposure including 2 who also reported hobby-related noise exposure. Fifty percent (2/4) of the individuals without any noise exposure had a hearing loss confirming previous reports that some of the population is vulnerable to the ototoxic effects of opioids. The percentage of population with hearing loss increased with hobby-related (58%) and occupational noise exposure (100%). Mixed MANOVA revealed a significant ear, frequency, and noise exposure interaction. Health professionals need to be aware of the possible ototoxic effects of opioids, since early detection of hearing loss from opium abuse may lead to cessation of abuse and further progression of hearing loss. The possibility that opium abuse may interact with noise exposure in determining auditory thresholds needs to be considered in noise exposed individuals who are addicted to opiates. Possible mechanisms of cochlear damage from opium abuse, possible reasons for individual susceptibility, and recommendations for future studies are presented in the article.

Influence of Nutrition on the Association Between Occupational Noise Exposures and Hearing Impairment in the US General Population

PP-29-184 Background/Aims: Recently, we have shown a dose-dependent elevation of hearing thresholds across the occupational noise levels in the US general population. Numerous animal studies suggest that dietary antioxidants (vitamins C and E) and other micronutrients (folate and vitamin B12) may play an important role in the pathogenesis of auditory disorders. We investigated potential modifying effects of dietary antioxidants and B-vitamins in the association with occupational noise and hearing loss. Methods: We examined 3922 adults from the National Health and Nutrition Examination Survey (NHANES) 1999–2004, a representative sample of the US general population. Occupational noise score was assessed by utilizing the O*NET (Occupational Information Network) exposure database (scored as 1–5) across numerous occupations. Air-conduction hearing threshold was computed as a pure-tone average (PTA) of 0.5, 1, 2, and 4 kHz and log-transformed. Quantitative dietary intake data were obtained by means of a 24-hour dietary recall interview. Linear regression models accounting for the complex sampling design were fit with interaction terms between occupational noise and quintiles of each dietary variable, adjusting for potential confounding factors including sociodemographic/clinical risk factors and nonoccupational noise exposures. Results: The mean of occupational noise score was 3.08 (SD: 0.02). An interquartile range increase in occupational noise score (0.91) was associated with a 10.12% (95% CI: 6.52–13.83) elevation of PTA. We found a statistically significant interaction between occupational noise score and intake of vitamin C on PTA (P for trend = 0.02). The lowest quintile of vitamin C group had a statistically significant elevation of PTA in relation to occupational noise (percent change = 15.92% [95% CI: 6.15–26.58]), whereas the highest quintile group had no association between occupational noise and PTA. No effect modification by other dietary factors was observed. Conclusion: This study suggests that higher intake of vitamin C may mitigate a harmful effect of occupational noise on hearing loss.