In an industrial work environment, at-risk behaviors such as poor posture and improper eye protection can be observed and corrected almost immediately. But another critical aspect of workplace safety often goes undetected– until the damage is already done. In the U.S., 22 million workers per year are at risk of occupational hearing loss [5]. Hearing damage typically occurs painlessly and progressively, but frequent and repeated exposure to high noise levels in the workplace can result in permanent hearing loss. Due to numerous sources of noise hazards such as heavy machinery and power tools, the mining, manufacturing, and construction industries experience the most incidences of work-induced hearing damage [1]. Although completely preventable, it has remained one of the most prevalent occupational health concerns for nearly three decades.
How we perceive sound
Noise is measured in decibels, using “A-weighted sound levels” (dBA) that measure how sound is perceived by the human ear. For example, a normal conversation would measure in at around 60 dBA, and the sound of a large truck being driven several yards away would be about 90 dBA [8]. Noise exposure is dependent on one’s proximity to the source of noise, as well as the duration of exposure to the source. In short, the louder the sound, the less time it takes to cause hearing damage.
The consequences of hearing damage
The legal limit of noise exposure is 90 dBA for an 8-hour work day, but it’s also possible for hearing damage to occur within these limits. A ringing sensation in the ears, temporary hearing loss after leaving work, or having to shout to be heard by coworkers are common warning signs indicative of short-term hearing damage, which can last for up to a week. The long-term effects grow exceedingly worse as more and more structural damage is inflicted upon the inner ear. It’s also worth noting that hearing damage is cumulative, meaning the risk of hearing loss grows greater with age [1]. While permanent hearing loss can result from frequent exposure to loud sounds, it could also be caused by under a minute of exposure to noise over 120 decibels. Permanent hearing loss cannot be medically or surgically reversed, makes it increasingly difficult to hear high-frequency sounds and speech, and often requires the use of hearing devices to compensate for the loss of function. Occupational hearing loss not only impairs an individual’s quality of life and vocational abilities; it also ends up costing businesses about $242 million a year in worker’s compensation [7].
Mitigating noise exposure at work
Every day, 4 million workers are put at risk of occupationally-induced hearing loss [5]. With so many at risk, prevention is more important than ever. The most generally accepted process of occupational risk mitigation is the hierarchy of controls, in which physically modifying the workplace is seen as most effective, while making changes on an individual level are least effective [3]. Although eliminating the hazard altogether would be the most logical form of mitigation, this is not a viable option in the context of an industrial workplace.
- Engineering controls require modifying or replacing equipment to reduce noise hazards at the source. Many organizations, including NASA, are choosing to be proactive by “buying quiet”, or specifying low noise levels when purchasing equipment in order to ensure a quieter workplace.
- Administrative controls change the way people work, which includes controlling noise exposure through distance, providing quiet or soundproof areas, and limiting time spent exposed to hazards through task rotation. Another supplementary method is to provide workers with training and education that emphasizes preventative behavior outside the workplace, such as avoiding loud environments or setting a maximum volume on portable audio devices.
- Personal protective equipment controls noise exposure on an individual level with Hearing Protection Devices (HPDs) such as earplugs and earmuffs. However, multiple studies have found this to be somewhat problematic as a primary approach; verbal communication and the ability to hear warning signals are critical aspects of performing most industrial job tasks, and HPDs diminish a worker’s ability to do both. As a result, HPD use among U.S. construction workers remains significantly low [2].
A less traditional method of reducing noise hazards is the workplace safety market itself, which often serves as a vehicle to connect innovation with industry needs. For example, in a recent press release, the Department of Labor announced the launch of the “Hear and Now – Noise Safety Challenge” in which entrepreneurs and inventors are invited to develop technological solutions to the problem of work-induced hearing loss; finalists will be able to pitch these ideas to a panel of investors and representatives from the U.S. Patent and Trademark Office.
Progress in occupational noise reduction
There has been significant progress in occupational noise mitigation over the past several decades: many large and medium-sized companies have implemented hearing conservation programs, independent regulatory agencies have issued updated noise regulation for the mining and railroad industries, and technological advances have drastically improved noise measurement equipment. The rate of work-induced hearing loss, however, establishes a need for further preventative action. For example, OSHA requires that general industry employers must implement a Hearing Conservation Program (HCP) when workers are exposed to noise levels of 85 dBA or higher over an 8-hour work day, which includes training, free hearing exams and protection, and evaluation of noise levels [7]. However, HCPs remain woefully under-enforced, leaving an over-reliance on personal protective equipment to mitigate noise exposure.
Medical journal Noise & Health suggests amending the current OSHA noise regulations—which have not been updated since 1983—to address the continuously high rates of occupational hearing loss, as well as the fact that agricultural workers, along with oil and gas service workers, are still not protected by noise regulations [6]. Since OSHA recently increased civil penalties and promised more thorough inspections, compliance with existing noise exposure laws are expected to increase in the next several years. In terms of regulatory changes, many suggest looking to Europe: current noise legislation is the most comprehensive of any developed nation, requiring quieter equipment, declaration of noise emission, and manufacturer incentives to exceed these requirements [4].
Sources
- Verbeek, J., Kateman, E., Morata, T., Dreschler, W., & Mischke, C. (2014). Interventions to prevent occupational noise-induced hearing loss: A Cochrane systematic review. International Journal Of Audiology, 53(sup2), S84-S96. http://dx.doi.org/10.3109/14992027.2013.857436
- Suter, A. (2002). Construction Noise: Exposure, Effects, and the Potential for Remediation; A Review and Analysis. AIHA Journal, 63(6), 768-789. http://dx.doi.org/10.1080/15428110208984768
- Hierarchy of Controls – NIOSH Workplace Safety and Health Topic. (2016). gov. Retrieved 8 August 2016, from http://www.cdc.gov/niosh/topics/hierarchy/
- Witt, B. (2013). Sound Source: Changes in EU Noise Directive. org. Retrieved 8 August 2016, from http://www.hearforever.org/tools-to-learn/sound-source-changes-in-eu-noise-directive
- Facts and Statistics: Noise – NIOSH Workplace Safety & Health. (2010). gov. Retrieved 8 August 2016, from http://www.cdc.gov/niosh/topics/noise/stats.html
- Suter, A. (2009). The hearing conservation amendment: 25 years later. Noise & Health, 11(42), 2. http://dx.doi.org/10.4103/1463-1741.45306
- Safety and Health Topics | Occupational Noise Exposure. (2016). gov. Retrieved 8 August 2016, from https://www.osha.gov/SLTC/noisehearingconservation/index.html
- National Institute on Deafness and Other Communication Disorders. (2010). I Love What I Hear! Common Sounds. Bethesda: U.S. Department of Health and Human Services.
