Occupational noise is the amount of acoustic energy received by an employee's auditory system when they are working in the industry. Occupational noise, or industrial noise, is often a term used in
occupational safety and health
Occupational safety and health (OSH), also commonly referred to as occupational health and safety (OHS), occupational health, or occupational safety, is a multidisciplinary field concerned with the safety, health, and welfare of people at wor ...
, as sustained exposure can cause permanent hearing damage.
Occupational noise is considered an
occupational hazard
An occupational hazard is a hazard experienced in the workplace. This encompasses many types of hazards, including chemical hazards, biological hazards (biohazards), psychosocial hazards, and physical hazards. In the United States, the Nation ...
traditionally linked to loud industries such as
ship-building
Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to befor ...
,
mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...
, railroad work,
welding
Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing Fusion welding, fusion. Welding is distinct from lower ...
, and
construction
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and com ...
, but can be present in any workplace where hazardous noise is present.
Regulation
In the US, the
National Institute for Occupational Safety and Health
The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the C ...
(NIOSH) and the
Occupational Safety and Health Administration
The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...
(OSHA) work together to provide standards and regulations for noise in the workplace.
National Institute for Occupational Safety and Health
The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the C ...
(NIOSH),
Occupational Safety and Health Administration
The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...
(OSHA),
Mine Safety and Health Administration
The Mine Safety and Health Administration (MSHA) () is a large agency of the United States Department of Labor which administers the provisions of the Federal Mine Safety and Health Act of 1977 (Mine Act) to enforce compliance with mandatory safet ...
(MSHA),
Federal Railroad Administration
The Federal Railroad Administration (FRA) is an agency in the United States Department of Transportation (DOT). The agency was created by the Department of Transportation Act of 1966. The purpose of the FRA is to promulgate and enforce rail saf ...
(FRA) have all set standards on hazardous occupational noise in their respective industries. Each industry is different, as workers' tasks and equipment differ, but most regulations agree that noise becomes hazardous when it exceeds 85
decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...
s, for an 8-hour time exposure (typical work shift). This relationship between allotted noise level and exposure time is known as an
exposure action value
An Exposure Action Value (EAV) or Action Value (AV) is a limit set on occupational exposure to noise where, when those values are exceeded, employers must take steps to monitor the exposure levels. These levels are measured in decibels. The Ameri ...
(EAV) or
permissible exposure limit
The permissible exposure limit (PEL or OSHA PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent such as high level noise. Permissible exposure limits are established by the Occupational ...
(PEL). The EAV or PEL can be seen as equations which manipulate the allotted exposure time according to the intensity of the industrial noise. This equation works as an inverse, exponential, relationship. As the industrial noise intensity increases, the allotted exposure time, to still remain safe, decreases. Thus, a worker exposed to a noise level of 100 decibels for 15 minutes would be at the same risk level as a worker exposed to 85 decibels for 8 hours. Using this mathematical relationship, an employer can calculate whether or not their employees are being overexposed to noise. When it is suspected that an employee will reach or exceed the PEL, a monitoring program for that employee should be implemented by the employer.
The above calculations of PEL and EAV are based on measurements taken to determine the intensity of that particular industrial noise.
A-weighted
A-weighting is the most commonly used of a family of curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level. A-weighting is applied to instrument-measured s ...
measurements are commonly used to determine noise levels that can cause harm to the human ear. There are also special exposure meters available that integrate noise over a period of time to give an
Leq value (equivalent sound pressure level), defined by standards.
Risks of occupational hearing loss
![Temporary threshold shift (hearing loss) after noise exposure](https://upload.wikimedia.org/wikipedia/commons/b/b1/Temporary_threshold_shift_%28hearing_loss%29_after_noise_exposure.jpg)
Occupational noise, if experienced repeatedly, at high intensity, for an extended period of time, can cause
noise-induced hearing loss
Noise-induced hearing loss (NIHL) is a Hearing loss, hearing impairment resulting from exposure to loud sound. People may have a loss of perception of a narrow range of Frequency, frequencies or impaired perception of sound including hyperacusi ...
(NIHL) which is then classified as
occupational hearing loss
Occupational hearing loss (OHL) is hearing loss that occurs as a result of occupational hazards, such as excessive noise and ototoxic chemicals. Noise is a common workplace hazard, and recognized as the risk factor for noise-induced hearing loss ...
. Most often, this is a type of
sensorineural hearing loss
Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the inner ear or sensory organ (cochlea and associated structures) or the vestibulocochlear nerve (cranial nerve VIII). SNHL accounts for about 90% of rep ...
.
Noise, in the context of industrial noise, is hazardous to a person's hearing because of its loud intensity through repeated long-term exposure. In order for
noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arise ...
to cause
hearing impairment
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken l ...
for the worker, the noise has to be close enough, loud enough, and sustained long enough to damage the
hair cell
Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates, and in the lateral line organ of fishes. Through mechanotransduction, hair cells detect movement in their environment. ...
s in the auditory system. These factors have been taken into account by the governing occupational health and safety organization to determine the unsafe noise exposure levels and durations for their respective industries.
Noise can also affect the safety of the employee and others. Noise can be a causal factor in
work accident
A work accident, workplace accident, occupational accident, or accident at work is a "discrete occurrence in the course of work" leading to physical or mental occupational injury. According to the International Labour Organization (ILO), more tha ...
s as it may mask hazards and warning signals and impede concentration. High intensity noise interferes with vital
workplace communication Workplace communication is the process of exchanging information and ideas, both verbally and non-verbally between one person or group and another person or group within an organization. It includes e-mails, videoconferencing, text messages, notes, ...
which increases the chance of accidents and decreases productivity.
Noise may also act synergistically with other hazards to increase the risk of harm to workers. In particular, toxic materials (e.g. some
solvent
A solvent (s) (from the Latin '' solvÅ'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...
s, metals, asphyxiants and pesticides) have some
ototoxic properties that may affect hearing function.
Modern thinking in
occupational safety and health
Occupational safety and health (OSH), also commonly referred to as occupational health and safety (OHS), occupational health, or occupational safety, is a multidisciplinary field concerned with the safety, health, and welfare of people at wor ...
further identifies noise as hazardous to workers' safety and health. This hazard is experienced in various places of employment and through a variety of sources.
Reduction
There are several ways to limit exposure to hazardous occupational noise. The
hierarchy of controls is a guideline for reducing hazardous noise. Before starting a noise reduction program, base noise levels should first be recorded. After this the company can start to eliminate the noise source. If the noise source cannot be eliminated, the company must try to reduce the noise with alternative methods. This process is called acoustic quieting.
Acoustic quieting Acoustic quieting is the process of making machinery quieter by damping vibrations to prevent them from reaching the observer. Machinery vibrates, causing sound waves in air, hydroacoustic waves in water, and mechanical stresses in solid matter. Qu ...
is the process of making machinery quieter by damping vibrations to prevent them from reaching the observer. The company can isolate the certain piece of machinery by placing materials on the machine or in between the machine and the worker to decreases the signal intensity that reaches the worker's ear.
If elimination and substitution are not sufficient in reducing the noise exposure,
engineering controls
Engineering controls are strategies designed to protect workers from hazardous conditions by placing a barrier between the worker and the hazard or by removing a hazardous substance through air ventilation. Engineering controls involve a physi ...
should be put in place by the employer. An engineering control usually changes the physical environment of a workplace. For noise reduction, an engineering control might be as simple as putting barriers in-between the noise source and the employee in order to disrupt the transmission path. An engineering control might also involve changing the machine that produces the noise. Ideally, most machines should be made with noise reduction in mind, but this doesn't always happen. Changing the machinery involved in an industrial process may not be possible, but is a good way to reduce the noise at its source.
![Bouchon arceau](https://upload.wikimedia.org/wikipedia/commons/8/8b/Bouchon_arceau.jpg)
To decrease an employee's exposure to hazardous noise, the company can also take
administrative control by limiting the employee's exposure time. This can be done by changing work shifts and switching employees out from the noise exposure area. An employer might also implement a training program so that employees can learn about the hazards of occupational noise. Other administrative controls might include restricting access to noisy areas as well as placing warning signs around those same areas. If all other controls fail to decrease the occupational noise exposure to an acceptable level,
hearing protection
A hearing protection device, also known as a HPD, is an ear protection device worn in or over the ears while exposed to hazardous noise and provide hearing protection to help prevent noise-induced hearing loss. HPDs reduce the level of the no ...
should be used. There are several types of
earplug
An earplug is a device that is inserted in the ear canal to protect the user's ears from loud noises, intrusion of water, foreign bodies, dust or excessive wind. Since they reduce the sound volume, earplugs are often used to help prevent hear ...
s that can be used to attenuate the noise to a safe level. Some earplug types include: single-use earplugs, multiple-use ear plugs, and banded ear plugs. Depending on the type of work being done and the needs of the employees, earmuffs might also be a good option. While earmuffs might not have as high of a noise reduction rating (NNR) as earplugs, they can be useful if the noise exposure isn't very high, or if an employee cannot wear earplugs.
Initiatives
Since the hazards of occupational noise exposure were realized, programs and initiatives such as the US
Buy Quiet
Buy Quiet is an American health and safety initiative to select and purchase the lowest noise emitting power tools and machinery in order to reduce occupational and community noise exposure. Buy Quiet Programs are examples of noise control strategi ...
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 machines. Additionally, the
Safe-In-Sound Award
The Safe-in-Sound Excellence in Hearing Loss Prevention Award is an occupational health and safety award that was established in 2007 through a partnership between the National Institute for Occupational Safety and Health (NIOSH) and the National ...
was created to recognize successes in hearing loss prevention programs or initiatives.
See also
*
Hearing conservation program
Hearing conservation programs are designed to prevent hearing loss due to noise. Hearing conservation programs require knowledge about risk factors such as noise and ototoxicity, hearing, hearing loss, protective measures to prevent hearing loss ...
*
Occupational hearing loss
Occupational hearing loss (OHL) is hearing loss that occurs as a result of occupational hazards, such as excessive noise and ototoxic chemicals. Noise is a common workplace hazard, and recognized as the risk factor for noise-induced hearing loss ...
*
Noise-induced hearing loss
Noise-induced hearing loss (NIHL) is a Hearing loss, hearing impairment resulting from exposure to loud sound. People may have a loss of perception of a narrow range of Frequency, frequencies or impaired perception of sound including hyperacusi ...
*
Buy Quiet
Buy Quiet is an American health and safety initiative to select and purchase the lowest noise emitting power tools and machinery in order to reduce occupational and community noise exposure. Buy Quiet Programs are examples of noise control strategi ...
*
Earplug
An earplug is a device that is inserted in the ear canal to protect the user's ears from loud noises, intrusion of water, foreign bodies, dust or excessive wind. Since they reduce the sound volume, earplugs are often used to help prevent hear ...
*
Earmuffs
Earmuffs are clothing accessories or personal protective equipment designed to cover a person's ears for hearing protection or warmth. They consist of a thermoplastic or metal head-band that fits over the top or back of the head, and a cushion ...
*
Protective clothing
Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, ele ...
*
A-weighting
A-weighting is the most commonly used of a family of curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level. A-weighting is applied to instrument-measured ...
*
ITU-R 468 noise weighting
*
Weighting filter
A weighting filter is used to emphasize or suppress some aspects of a phenomenon compared to others, for measurement or other purposes.
Audio applications
In each field of audio measurement, special units are used to indicate a weighted measure ...
*
Equal-loudness contour
An equal-loudness contour is a measure of sound pressure level, over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. The unit of measurement for loudness levels is the phon and ...
*
Safe-In-Sound Award
The Safe-in-Sound Excellence in Hearing Loss Prevention Award is an occupational health and safety award that was established in 2007 through a partnership between the National Institute for Occupational Safety and Health (NIOSH) and the National ...
Excellence in Hearing Loss Prevention
General:
*
Health effects from noise
Noise health effects are the physical and psychological health consequences of regular exposure to consistent elevated sound levels. Noise from traffic, in particular, is considered by the World Health Organization to be one of the worst environm ...
*
Noise control
Noise control or noise mitigation is a set of strategies to reduce noise pollution or to reduce the impact of that noise, whether outdoors or indoors.
Overview
The main areas of noise mitigation or abatement are: transportation noise control, ...
*
Noise pollution
Noise pollution, also known as environmental noise or sound pollution, is the propagation of noise with ranging impacts on the activity of human or animal life, most of them are harmful to a degree. The source of outdoor noise worldwide is main ...
*
Noise regulation
References
External links
Occupational Safety & Health AdministrationEstablishing an OSHA-Compliant Occupational Hearing Testing Program
{{Employment
Noise
Noise pollution
Occupational safety and health
Industrial hygiene
Sound
Acoustics