# Industrial noise

Temporary hearing loss after loud noise exposure. If such exposure a enough long, this temporary threshold shift became may permanent.[1]

Industrial noise, or occupational noise, is often a term used in relation to environmental health and safety, rather than nuisance, as sustained exposure can cause permanent hearing damage. Industrial noise is an occupational hazard traditionally linked to heavy industries such as ship-building and associated with noise-induced hearing loss (NIHL), a form of occupational hearing loss. Modern thinking in occupational safety and health further identifies noise as hazardous to worker safety and health in many places of employment and by a variety of means.

Noise can cause hearing impairment at long-term exposures of over 85 decibels (known as an exposure action value), and it also acts as a causal factor for stress and raises systolic blood pressure.

Noise can be a causal factor in work accidents, both by masking hazards and warning signals, and by impeding concentration. Noise acts synergistically with other hazards to increase the risk of harm to workers. In particular, noise and toxic (e.g. some solvents, metals, asphyxiants and pesticides) have some ototoxic properties may affect the hearing function.[2][3]

A-weighted measurements are commonly used to determine noise levels that can cause harm to the human ear, and special exposure meters are available that integrate noise over a period of time to give an Leq value (equivalent sound pressure level), defined by standards.

## Reduction

Acoustic quieting is the process of making machinery quieter by damping vibrations to prevent them from reaching the observer.

Noise decreases as distance from its source increases. When two identical noise sources are side by side producing a recorded noise of, say, 100 dB(A) the reduction in noise from removing one of the noise sources is about 3 dB, resulting in 97 dB(A). When the distance to a noise source is doubled the recorded noise level is reduced by 6 dB, sometimes called the Rule of 6.

The noise attenuation in decibels at a distance from the source ${\displaystyle d}$, knowing the SPL at distance ${\displaystyle d_{0}}$, is ${\displaystyle 20log_{10}\left({\frac {d}{d_{0}}}\right)}$. If the distance is doubled, i.e. ${\displaystyle \left({\frac {d}{d_{0}}}\right)=2}$, the attenuation becomes 6.02 dB (6 for most practical purposes).

Experts have developed a number of standards for noise reduction and isolation of its sources from people.[4][5][6][7][8][9]

## Regulation

In the United States, the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) work together to provide standards and regulations for noise in the workplace. [10][11] Industrial noise can also be regulated by legislation. A 2012 Cochrane review found low-quality evidence that legislation reduced industrial noise both immediately and in the long-term. [12]

## Initiatives

Since the hazards of occupational noise exposure were realized, programs and initiatives such as the US Buy Quiet program have been set up to regulate or discourage noise exposure. The Buy Quiet initiative promotes the purchase of quieter tools and equipment and encourages manufacturers to design quieter equipment.[13] Additionally, the Safe-In-Sound Award was created to recognize successes in hearing loss prevention programs or initiatives. [14]

General:

## References

1. ^ Izmerov, Nikolai; Suvorov, Herman; Prokopenko, Ludmila (2001). "Chapter 4. Occupational hearing loss". The man and the noise (Человек и шум) (in Russian). Moscow: ГЕОТАР-МЕД. p. 103. ISBN 5-9231-0057-6.
2. ^ Morata, Thais C. (2007-01-01). "Promoting hearing health and the combined risk of noise-induced hearing loss and ototoxicity". Audiological Medicine. 5 (1): 33–40. doi:10.1080/16513860601159018. ISSN 1651-386X.
3. ^ Johnson and Morata, TC (2010). "Occupational exposure to chemicals and hearing impairment" (PDF). Arbete och Hälsa. 44 (4): 177 pp. Retrieved 27 June 2016.
4. ^
5. ^
6. ^
7. ^
8. ^ ISO/TR 11688-2:1998 Acoustics - Recommended practice for the design of low-noise machinery and equipment - Part 2: Introduction to the physics of low-noise design
9. ^ ISO/TR 11688-1:1995 Acoustics -- Recommended practice for the design of low-noise machinery and equipment - Part 1: Planning
10. ^ "Occupational Noise Exposure: Standards". Occupational Safety and Health Administration. Retrieved 2016-07-14.
11. ^ "Noise and Hearing Loss Prevention: National Goals, Policies, and Standards". Centers for Disease Control and Prevention. Retrieved 2016-07-14.
12. ^ Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wouter A.; Mischke, Christina (2012). "Interventions to prevent occupational noise-induced hearing loss". The Cochrane Database of Systematic Reviews. 10: CD006396. doi:10.1002/14651858.CD006396.pub3. ISSN 1469-493X. PMID 23076923.
13. ^ "Buy Quiet". Centers for Disease Control and Prevention.
14. ^ "Safe-in-Sound:Excellence in Hearing Loss Prevention Award". Safe-in-Sound. Retrieved 2016-07-14.