Have you ever thought about how the noise levels at your workplace might be affecting workers’ health? Today, we will explore the topic of occupational noise management. Whether working in a loud factory, a busy office, or any other environment where noise is a constant companion, managing occupational noise is vital for your well-being and productivity.
In this post, we’ll dive into the key strategies for effectively managing noise at work. We’ll discuss why it’s important to control noise levels, the impact of excessive noise on health, and practical solutions to mitigate these effects. By the end of this post, you’ll be equipped with the knowledge to create a quieter and healthier workplace.
What You’ll Learn
- Importance of Noise Control: Understand why managing noise levels in the workplace is crucial for health and safety.
- Health Impacts of Excessive Noise: Learn about the potential health effects of prolonged noise exposure and how it can affect your daily life.
- Practical Noise Management Strategies: Discover effective techniques and tools for reducing noise levels and creating a more comfortable work environment.
Introduction
One of the most significant hazards in the workplace is noise exposure. Noise is an inherent aspect of daily life, both at work and socially. However, excessive or prolonged exposure can lead to hearing loss, hearing quality impairment, and other health effects.
The onset of these effects sometimes occurs after acute exposure but mainly after a considerable latency period.
Noise and Sound
Noise is the term that describes the interpretation of sound and whether it is wanted or hazardous. As sound energy is transmitted in waves, it causes a slight increase in air pressure. When the vibrating motion reverses direction, a partial rarefaction occurs. The alternating compression and rarefaction of the air cause minor fluctuations in pressure, which the ear’s hair cells detect, converting them into electrical pulses and sending them to the brain, where they are interpreted as noise.
Controlling Noise Exposure
Several techniques are available to minimize the risk of noise exposure, following the hierarchy of control (Crocker & Kessler, 2018).
Elimination and Substitution
These control techniques are best considered during the initial planning and design phases (Gabbert et al., 2017), as retrofitting and redesigning are often costly (Yankaskas et al., 2017). A “buy quiet” approach can also eliminate high-risk noise sources by ensuring that such equipment or tools are not brought into the workplace.
With substitution, the process or inputs can be changed to minimize noise. Some examples of substitution include using pliers instead of a hammer to reduce impact noise and using self-tapping screws or rivets rather than nails.
Engineering Controls
One of the most cost-effective methods to minimize noise exposure is to reduce its transmission through absorption, dampening (Saleh et al., 2017), or isolation methods.
When sound hits an object or media, it can act in three ways: reflected, absorbed, or transmitted. Sound movement is related to the ratio of wavelength to the size of the reflecting surface. For instance, low-wavelength (high-frequency) sounds tend to reflect at the same angle of incidence.
Noise can be emitted equally in all directions from the source or in a directional pattern. The intensity of the sound will depend on both the sound power level and the movement of the sound waves. In the simplest case of noise propagation, where there is no reflection (an anechoic chamber), sound distribution will be almost equivalent to a spherical free field.
The free field refers to conditions where the inverse square law applies to the sounds propagating from the source. However, if a piece of equipment were to be placed in a room with a sound-reflective floor but absorbent walls and ceiling, then the noise would be distributed in a half-spherical pattern. This, in effect, causes a doubling of the sound intensity as the spherical free field is reduced by half and is sometimes called the directivity factor (Q).
Therefore, for a half-spherical radiation pattern, Q equals two. If one wall plus the floor causes reflection, the noise will be distributed in a one-quarter spherical pattern (Q=4). Where the machine is placed in the corner of the room, and there are three sources of reflection, the sound is radiated in a one-eight spherical pattern (Q=8).
Administrative Controls
Some examples of administrative controls include:
- Minimizing exposure duration through a reduction in exposure time or job rotation
- Organizing for high-risk operations to be conducted out of hours or when few workers will be exposed
- Re-organizing the workplace to locate work activities or noisy equipment away from the main work area
- The noise contour plan results will mark zones where noise exposure may exceed regulatory or organizational standards.
- Limiting or prohibiting specific high-risk tasks
- Training workers on the effects of noise exposure, basic acoustics, and how noise is measured and controlled
- Audiometric testing.
Personal Protective Equipment (PPE)
PPE should be the final choice in minimizing the risk associated with noise exposure. As with all forms of PPE, its effectiveness is governed by its application, which is affected by human behavior.
The fit and design of some hearing protective devices can affect their suitability for use. Some workers may have trouble inserting or wearing the equipment. There are also hygienic reasons for minimizing the use of hearing protection devices.
There are four main types of hearing protection devices that are available:
- Earplugs
- Earmuffs
- Canal caps
- Acoustic helmets.
The principle of noise reduction using hearing protection devices is five-fold:
- Completely cover the entire ear
- Cover the entrance to the ear canal
- Plug the ear canal
- Neutralize noise before it reaches the ear by electronic methods
- Cover the outer ear as well as a portion of the head.
Summary
Noise is a term used to describe our interpretation of sounds. However, excessive exposure may have physiological and psychological effects. The hierarchy of control can be used to reduce exposure to occupational noise.
Helpful Resources
- Conducting a Noise Survey Blog Post, by Megan Tranter
- Occupational Noise and Workplace Acoustics, by Dariusz Pleban
Bibliography
Crocker, M., & Kessler, F. (2018). Noise and Noise Control. CRC Press. https://books.google.com/books?hl=en&lr=&id=gEcPEAAAQBAJ&oi=fnd&pg=PP1&dq=noise+control&ots=GZGdp2wSpK&sig=tW-YorG18-6odgUs_lmN4af85jM#v=onepage&q=noise%20control&f=false
Gabbert, U., Duvigneau, F., & Ringwelski, S. (2017). NOISE CONTROL OF VEHICLE DRIVE SYSTEMS. Mechanical Engineering, 15(2), 183-200. http://casopisi.junis.ni.ac.rs/index.php/FUMechEng/article/view/3026/1752
Saleh, S., Woskie, S., & Bello, A. (2017). The Use of Noise Dampening Mats to Reduce Heavy-Equipment Noise Exposures in Construction. Safety and Health at Work, 8(2), 226-230. https://www.sciencedirect.com/science/article/pii/S2093791116302232
Yankaskas, K., Fischer, R., Spence, J., & Komrower, J. (2017). Engineering out the noise. Hearing Research, 349(June), 37-41. https://www.sciencedirect.com/science/article/pii/S0378595516302817
