Noise#Electronic noise
{{Short description|Unwanted sound}}
{{about|noise as an unwanted acoustic phenomenon|the general signal phenomenon|Noise (spectral phenomenon)||Noise (disambiguation)}}
File:Noise Research Program on Hangar Apron - GPN-2000-001457.jpg researchers at Glenn Research Center measuring aircraft engine noise in 1967]]
Noise is sound, chiefly unwanted, unintentional, or harmful sound considered unpleasant, loud, or disruptive to mental or hearing faculties. 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 arises when the brain receives and perceives a sound.{{Cite web|url=http://physics.info/sound/|title=The Nature of Sound – The Physics Hypertextbook|last=Elert|first=Glenn|website=physics.info|access-date=2016-06-20}}{{Cite web|url=http://pages.jh.edu/~virtlab/ray/acoustic.htm|title=The Propagation of sound|website=pages.jh.edu|access-date=2016-06-20}} Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, noise in electronics may not be audible to the human ear and may require instruments for detection.{{Cite web|url=http://electronicdesign.com/electromechanical/what-s-difference-between-acoustical-and-electrical-noise-components|title=What's The Difference Between Acoustical And Electrical Noise In Components?|website=electronicdesign.com|access-date=2016-06-20|date=2012-10-03}}
In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss. This signal noise is commonly measured using A-weighting{{citation |url= http://storeycountywindfarms.org/ref3_Impact_Sound_Pressure.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://storeycountywindfarms.org/ref3_Impact_Sound_Pressure.pdf |archive-date=2022-10-09 |url-status=live |author1=Richard L. St. Pierre, Jr. |author2=Daniel J. Maguire |title=The Impact of A-weighting Sound Pressure Level Measurements during the Evaluation of Noise Exposure |date=July 2004 |access-date=2011-09-13}} or ITU-R 468 weighting.{{cite web|title=RECOMMENDATION ITU-R BS.468-4 – Measurement of audio-frequency noise voltage|url=http://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.468-4-198607-I!!PDF-E.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.468-4-198607-I!!PDF-E.pdf |archive-date=2022-10-09 |url-status=live|website=www.itu.int|publisher=International Telecommunication Union|access-date=18 October 2016}} In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of a signal.{{Cite web|url=http://www.merriam-webster.com/dictionary/noise|title=Definition of NOISE|website=www.merriam-webster.com|access-date=2016-06-20}}{{Cite web|url=http://www.oxforddictionaries.com/us/definition/american_english/noise|archive-url=https://web.archive.org/web/20130614003024/http://oxforddictionaries.com/us/definition/american_english/noise|url-status=dead|archive-date=June 14, 2013|title=noise: definition of noise in Oxford dictionary (American English) (US)|website=www.oxforddictionaries.com|access-date=2016-06-20}}
Measurement
Sound is measured based on the amplitude and frequency of a sound wave. Amplitude measures how forceful the wave is. The energy in a sound wave is measured in decibels (dB), the measure of loudness, or intensity of a sound; this measurement describes the amplitude of a sound wave. Decibels are expressed in a logarithmic scale. On the other hand, pitch describes the frequency of a sound and is measured in hertz (Hz).{{Cite web|url=http://sciencelearn.org.nz/Contexts/The-Noisy-Reef/Science-Ideas-and-Concepts/Measuring-sound|title=Measuring sound|website=Sciencelearn Hub|access-date=2016-06-20|archive-date=2016-12-31|archive-url=https://web.archive.org/web/20161231180252/http://sciencelearn.org.nz/Contexts/The-Noisy-Reef/Science-Ideas-and-Concepts/Measuring-sound|url-status=dead}}
The main instrument to measure sounds in the air is the Sound Level Meter. There are many different varieties of instruments that are used to measure noise - Noise Dosimeters are often used in occupational environments, noise monitors are used to measure environmental noise and noise pollution, and recently smartphone-based sound level meter applications (apps){{Cite web|url=https://blogs.cdc.gov/niosh-science-blog/2014/04/09/sound-apps/|title=So How Accurate Are These Smartphone Sound Measurement Apps? {{!}} {{!}} Blogs {{!}} CDC|website=blogs.cdc.gov|date=9 April 2014 |language=en-us|access-date=2018-06-15}} are being used to crowdsource and map recreational and community noise.{{Cite news|url=http://noiseandthecity.org/noisescore/|title=NoiseScore: A Free Smartphone App for Community Noise Issues With Live Map|work=Noiseandthecity.org|access-date=2018-06-15|language=en-US|archive-date=2018-06-16|archive-url=https://web.archive.org/web/20180616001925/http://noiseandthecity.org/noisescore/|url-status=dead}}{{Cite web|url=https://www.soundprint.co/|title=soundprint – Find Your Quiet Place|website=www.soundprint.co|language=en-US|access-date=2018-06-15}}{{Cite web|url=http://www.ihearu.co/|title=iHEARu|website=www.ihearu.co|language=en|access-date=2018-06-15}}
A-weighting is applied to a sound spectrum to represent the sound that humans are capable of hearing at each frequency. Sound pressure is thus expressed in terms of dBA. 0 dBA is the softest level that a person can hear. Normal speaking voices are around 65 dBA. A rock concert can be about 120 dBA.
Recording and reproduction
In audio, recording, and broadcast systems, audio noise refers to the residual low-level sound (four major types: hiss, rumble, crackle, and hum) that is heard in quiet periods of program. This variation from the expected pure sound or silence can be caused by the audio recording equipment, the instrument, or ambient noise in the recording room.{{Cite web|url=http://www.audioshapers.com/blog/audio-noise.html|title=Audio Noise-Hiss, Hum, Rumble & Crackle|website=AudioShapers|access-date=2016-06-23}}
In audio engineering it can refer either to the acoustic noise from loudspeakers or to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as hiss. This signal noise is commonly measured using A-weighting or ITU-R 468 weighting
Noise is often generated deliberately and used as a test signal for audio recording and reproduction equipment.
Environmental noise
{{Main article|Environmental noise}}
Environmental noise is the accumulation of all noise present in a specified environment. The principal sources of environmental noise are surface motor vehicles, aircraft, trains and industrial sources.{{Cite journal|last1=Stansfeld|first1=Stephen A.|last2=Matheson|first2=Mark P.|date=2003-12-01|title=Noise pollution: non-auditory effects on health|journal=British Medical Bulletin|language=en|volume=68|issue=1|pages=243–257|doi=10.1093/bmb/ldg033|issn=0007-1420|pmid=14757721|doi-access=free}} These noise sources expose millions of people to noise pollution that creates not only annoyance, but also significant health consequences such as elevated incidence of hearing loss, cardiovascular disease, and many others.Tompkins, Olga, MPH, rN, SM, CSP. Secondhand Noise and Stress. AAOHN J. 2009;57(10):436. Cited in: Your Journals@Ovid Full Text at http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=reference&D=yrovftk&NEWS=N&AN=00001830-200910000-00007 . Accessed July 13, 2021.Goines, L., & Hagler, L. (2007). Noise pol-lution: A modern plague. Retrieved July 20, 2009, from www.medscape.com/viewarticle/554566{{Cite journal|title=EHP – Environmental Noise Pollution in the United States: Developing an Effective Public Health Response|journal=Environmental Health Perspectives|volume=122|issue=2|pages=115–119|doi=10.1289/ehp.1307272|pmid = 24311120|pmc=3915267|year=2014|last1=Hammer|first1=Monica S.|last2=Swinburn|first2=Tracy K.|last3=Neitzel|first3=Richard L.|bibcode=2014EnvHP.122..115H }} Urban noise is generally not of an intensity that causes hearing loss but it interrupts sleep, disturbs communication and interferes with other human activities.{{Cite book|title=Encyclopedia of the City|last=Caves|first=R. W.|publisher=Routledge|year=2004|isbn=9780415252256|pages=493}} There are a variety of mitigation strategies and controls available to reduce sound levels including source intensity reduction, land-use planning strategies, noise barriers and sound baffles, time of day use regimens, vehicle operational controls and architectural acoustics design measures.
Regulation
{{Main article|Noise regulation}}
Certain geographic areas or specific occupations may be at a higher risk of being exposed to constantly high levels of noise; regulation may prevent negative health outcomes. Noise regulation includes statutes or guidelines relating to sound transmission established by national, state or provincial and municipal levels of government. Environmental noise is governed by laws and standards which set maximum recommended levels of noise for specific land uses, such as residential areas, areas of outstanding natural beauty, or schools. These standards usually specify measurement using a weighting filter, most often A-weighting.{{Cite web|url=http://earthjournalism.net/resources/noise-pollution-managing-the-challenge-of-urban-sounds|title=Noise Pollution: Managing the Challenge of Urban Sounds|last=Bhatia|first=Rajiv|date=May 20, 2014|website=Earth Journalism Network|access-date=June 23, 2016}}{{Cite web|url=http://www.kineticsnoise.com/industrial/noise_ordinance.html|title=Noise Ordinance: Noise Regulations from U.S. Cities|website=www.kineticsnoise.com|access-date=2016-06-23}}
= United States =
In 1972, the Noise Control Act was passed to promote a healthy living environment for all Americans, where noise does not pose a threat to human health. This policy's main objectives were: (1) establish coordination of research in the area of noise control, (2) establish federal standards on noise emission for commercial products, and (3) promote public awareness about noise emission and reduction.{{Cite web|url=https://www.epa.gov/laws-regulations/summary-noise-control-act|title=Summary of the Noise Control Act |website=Environmental Protection Agency |language=en|access-date=2016-06-16|date=2013-02-22}}Noise Control Act of 1972, P.L. 92-574, 86 Stat. 1234, {{Usc|42|4901}} – {{Usc|42|4918}}.
The Quiet Communities Act of 1978 promotes noise control programs at the state and local level and developed a research program on noise control.{{Cite web|url=https://www.govtrack.us/congress/bills/95/s3083/text|title=Text of S. 3083 (95th): Quiet Communities Act (Passed Congress/Enrolled Bill version) – GovTrack.us|website=GovTrack.us|access-date=2016-06-16}} Both laws authorized the Environmental Protection Agency to study the effects of noise and evaluate regulations regarding noise control.{{Cite web|url=https://www.epa.gov/clean-air-act-overview/title-iv-noise-pollution|title=Title IV – Noise Pollution |website=Environmental Protection Agency |language=en|access-date=2016-06-16|date=2015-06-03}}
The National Institute for Occupational Safety and Health (NIOSH) provides recommendation on noise exposure in the workplace.{{Cite web|url=https://www.cdc.gov/niosh/topics/noise/stats.html|title=CDC – Facts and Statistics: Noise – NIOSH Workplace Safety & Health|website=www.cdc.gov|access-date=2016-06-15}}{{Cite web|url=http://blogs.cdc.gov/niosh-science-blog/2016/02/08/noise/|title=CDC – NIOSH Science Blog – Understanding Noise Exposure Limits: Occupational vs. General Environmental Noise|website=blogs.cdc.gov|date=8 February 2016 |access-date=2016-06-15}} In 1972 (revised in 1998), NIOSH published a document outlining recommended standards relating to the occupational exposure to noise, with the purpose of reducing the risk of developing permanent hearing loss related to exposure at work.{{Cite journal|url=https://www.cdc.gov/niosh/docs/1970/73-11001.html|title=CDC – NIOSH Publications and Products – Criteria for a Recommended Standard: Occupational Exposure to Noise (73-11001)|website=www.cdc.gov|access-date=2016-06-15|doi=10.26616/NIOSHPUB76128|year=1975|doi-access=free|url-access=subscription}} This publication set the recommended exposure limit (REL) of noise in an occupation setting to 85 dBA for 8 hours using a 3-dB exchange rate (every 3-dB increase in level, duration of exposure should be cut in half, i.e., 88 dBA for 4 hours, 91 dBA for 2 hours, 94 dBA for 1 hour, etc.). However, in 1973 the Occupational Safety and Health Administration (OSHA) maintained the requirement of an 8-hour average of 90 dBA. The following year, OSHA required employers to provide a hearing conservation program to workers exposed to 85 dBA average 8-hour workdays.{{Cite web|url=https://www.osha.gov/dts/osta/otm/new_noise/index.html#effectsofexcessive|title=OSHA Technical Manual (OTM) {{!}} Section III: Chapter 5 – Noise|website=www.osha.gov|access-date=2016-06-15}}
= Europe =
The European Environment Agency regulates noise control and surveillance within the European Union.{{Cite web|url=http://www.eea.europa.eu/themes/noise/policy-context|title=Noise: Policy Context|date=June 3, 2016|website=European Environmental Agency|access-date=June 16, 2016}} The Environmental Noise Directive was set to determine levels of noise exposure, increase public access to information regarding environmental noise, and reduce environmental noise.{{Cite web|url=http://ec.europa.eu/environment/noise/directive_en.htm|title=Directive – Noise – Environment – European Commission|website=ec.europa.eu|access-date=2016-06-16}}{{Cite web|url=http://ec.europa.eu/enlargement/pdf/turkey/ipa/2009/tr2009_032703-environmental_noise_directive_en.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://ec.europa.eu/enlargement/pdf/turkey/ipa/2009/tr2009_032703-environmental_noise_directive_en.pdf |archive-date=2022-10-09 |url-status=live|title=Standard Summary Project Fiche: Implementation Capacity for Environmental Noise Directive|website=European Commission|access-date=June 16, 2016}} Additionally, in the European Union, underwater noise is a pollutant according to the Marine Strategy Framework Directive (MSFD).{{cite web|url=http://ec.europa.eu/environment/marine/eu-coast-and-marine-policy/marine-strategy-framework-directive/index_en.htm|title=Our Oceans, Seas and Coasts|work=europa.eu|date=8 February 2024 }} The MSFD requires EU Member States to achieve or maintain Good Environmental Status, meaning that the "introduction of energy, including underwater noise, is at levels that do not adversely affect the marine environment".
Health effects
{{Main article|Health effects from noise|Noise-induced hearing loss}}
File:20230609 Average noise levels outside US homes.svg
File:Система производственного контроля эффективности СИЗ органа слуха.jpg
Exposure to noise is associated with several negative health outcomes. Depending on duration and level of exposure, noise may cause or increase the likelihood of hearing loss, high blood pressure, ischemic heart disease, sleep disturbances, injuries, and even decreased school performance.{{Cite journal|last1=Passchier-Vermeer|first1=W|last2=Passchier|first2=W F|date=2000-03-01|title=Noise exposure and public health.|journal=Environmental Health Perspectives|volume=108|issue=Suppl 1|pages=123–131|issn=0091-6765|pmc=1637786|pmid=10698728|doi=10.1289/ehp.00108s1123|jstor=3454637|bibcode=2000EnvHP.108S.123P}} When noise is prolonged, the body's stress responses can be triggered; which can include increased heartbeat, and rapid breathing. There are also causal relationships between noise and psychological effects such as annoyance, psychiatric disorders, and effects on psychosocial well-being.
Noise exposure has increasingly been identified as a public health issue, especially in an occupational setting, as demonstrated with the creation of NIOSH's Noise and Hearing Loss Prevention program.{{Cite web|url=https://www.cdc.gov/niosh/topics/noise/default.html|title=CDC – Noise and Hearing Loss Prevention – NIOSH Workplace Safety and Health Topi|website=www.cdc.gov|access-date=2016-06-15}} Noise has also proven to be an occupational hazard, as it is the most common work-related pollutant.{{Cite web|url=http://blogs.cdc.gov/niosh-science-blog/2016/04/27/hearing-loss-years-lost/|title=Measuring the Impact of Hearing Loss on Quality of Life|last=Masterson|first=Elizabeth|date=2016-04-27|website=Centers for Disease Control and Prevention|access-date=2016-06-15}} Noise-induced hearing loss, when associated with noise exposure at the workplace is also called occupational hearing loss. For example, some occupational studies have shown a relation between those who are regularly exposed to noise above 85 decibels to have higher blood pressure than those who are not exposed.Stansfield, S. A., & Matheson, M. P. (2003). Noise pollution: Non-auditory effects on health. British Medical Bulletin, 68, 243-257.
= Hearing loss prevention =
While noise-induced hearing loss is permanent, it is also preventable.{{Cite web|url=https://www.nidcd.nih.gov/health/noise-induced-hearing-loss#6|title=Noise-induced Hearing Loss|date=March 2014|website=National Institute on Deafness and Other Communication Disorders (NIDCD)|publisher=National Institute of Health|access-date=June 16, 2016}} Particularly in the workplace, regulations may exist limiting permissible exposure limit to noise. This can be especially important for professionals working in settings with consistent exposure to loud sounds, such as musicians, music teachers and audio engineers.{{Cite web|url=http://blogs.cdc.gov/niosh-science-blog/2015/07/07/musicians-hearing-loss/|title=Turn it Down: Reducing the Risk of Hearing Disorders Among Musicians |last1=Kardous|first1=Chuck |last2=Morata|first2=Thais|date=2015-07-07|website= Centers for Disease Control and Prevention|access-date=2016-06-15|last3=Themann|first3=Christa|last4=Spears|first4=Patricia|last5=Afanuh|first5=Sue}} Examples of measures taken to prevent noise-induced hearing loss in the workplace include engineering noise control, the Buy-Quiet initiative,{{Cite web |url=https://www.cdc.gov/niosh/topics/buyquiet/default.html/ |title=Buy Quiet |website=Centers for Disease Control and Prevention|access-date=2016-06-16}}{{Cite web|url=http://blogs.cdc.gov/niosh-science-blog/2011/11/04/buy-quiet/|title=Buy Quiet|last1=Hudson|first1=Heidi|last2=Hayden|first2=Chuck|date=2011-11-04|website=Centers for Disease Control and Prevention|access-date=2016-06-15}} creation of the Safe-In-Sound award, and noise surveillance.{{Cite web|url=http://blogs.cdc.gov/niosh-science-blog/2009/11/24/hearing/|title=Workplace Hearing Loss|last1=Murphy|first1=William|last2=Tak|first2=SangWoo|date=2009-11-24|website=Centers for Disease Control and Prevention|access-date=2016-06-15}}
OSHA requires the use of hearing protection. But the HPD (without individual selection, training and fit testing) does not significantly reduce the risk of hearing loss.{{cite book |last1=Berger |first1=Elliott H.|last2= Voix |first2= Jérémie |editor=D.K. Meinke |editor2=E.H. Berger |editor3=R. Neitzel |editor4=D.P. Driscoll |editor5=K. Bright |title=The Noise Manual |date=2018 |publisher=American Industrial Hygiene Association |location=Falls Church, Virginia |pages=255–308 |edition=6th |url=https://online-ams.aiha.org/amsssa/ecssashop.show_product_detail?p_mode=detail&p_product_serno=2719 |access-date=10 August 2022 |language=en |chapter=Chapter 11: Hearing Protection Devices}} For example, one study covered more than 19 thousand workers, some of whom usually used hearing protective devices, and some did not use them at all. There was no statistically significant difference in the risk of noise-induced hearing loss.{{cite journal |author=Groenewold M.R. |author2=Masterson E.A. |author3=Themann C.L. |author4=Davis R.R. |title=Do hearing protectors protect hearing? |journal=American Journal of Industrial Medicine |date=2014 |volume=57 |issue=9 |pages=1001–1010 |doi=10.1002/ajim.22323 |pmid=24700499 |url=https://stacks.cdc.gov/view/cdc/36768 |access-date=15 October 2022 |publisher=Wiley Periodicals |pmc=4671486 |issn=1097-0274}}
Literary views
Roland Barthes distinguishes between physiological noise, which is merely heard, and psychological noise, which is actively listened to. Physiological noise is felt subconsciously as the vibrations of the noise (sound) waves physically interact with the body while psychological noise is perceived as our conscious awareness shifts its attention to that noise.{{cite book|last=Barthes|first=Roland |title=The Responsibility of Forms: Critical Essays on Music, Art and Representation|url=https://books.google.com/books?id=g6konQEACAAJ|year=1985|publisher=Hill and Wang|location=New York|isbn=9780809080755}}
Luigi Russolo, one of the first composers of noise music,{{cite book|editor1=Chilvers, Ian |editor2=Glaves-Smith, John |title=A Dictionary of Modern and Contemporary Art|url=https://books.google.com/books?id=mwf6RVGYLjgC&pg=PA619|year=2009|publisher=Oxford University Press|location=Oxford|isbn=978-0-19-923965-8|pages=619–620}} wrote the essay The Art of Noises. He argued that any kind of noise could be used as music, as audiences become more familiar with noises caused by technological advancements; noise has become so prominent that pure sound no longer exists.{{cite book|editor1=Cox, Christoph |editor2=Warner, Daniel |title=Audio Culture: Readings in Modern Music|chapter=The art of noises: futurist manifesto|author= Russolo, Luigi |chapter-url=https://books.google.com/books?id=FgDgCOSHPysC&pg=PA10|year=2004|publisher=Continuum|location=New York|isbn=978-0-8264-1615-5|pages=10ff}}
Avant-garde composer Henry Cowell claimed that technological advancements have reduced unwanted noises from machines, but have not managed so far to eliminate them.{{cite book|editor1=Cox, Christoph |editor2=Warner, Daniel |title=Audio Culture: Readings in Modern Music|chapter=The joys of noise|author= Cowell, Henry|chapter-url=https://books.google.com/books?id=FgDgCOSHPysC&pg=PA22|year=2004|publisher=Continuum|location=New York|isbn=978-0-8264-1615-5|page=22}}
Felix Urban sees noise as a result of cultural circumstances. In his comparative study on sound and noise in cities, he points out that noise regulations are only one indicator of what is considered as harmful. It is the way in which people live and behave (acoustically) that determines the way how sounds are perceived.{{Cite book|title=Acoustic Competence Investigating sonic empowerment in urban cultures|last=Urban, Felix|others=Tectum Verlag|year=2016 |isbn=978-3-8288-3683-9|edition=1. Auflage|location=Marburg|oclc=951121194}}
See also
{{div col|colwidth=20em}}
- Association of Noise Consultants
- Background noise
- Colors of noise
- Impulse noise (acoustics)
- International Noise Awareness Day
- Intonarumori
- Human auditory ecology
- Loud music
- Noise and vibration on maritime vessels
- Noise calculation
- Noise control
- Noise in music
- Noise music
- Noise pollution
- Noise reduction
- Silence
- Sound level meter
- Soundscape
- The Hum
- White noise
{{div col end}}
References
{{Reflist|30em}}
Further reading
- {{cite book | title = Noise | publisher = Viking Press | year = 2006 | isbn = 978-0-670-03495-6 | last = Kosko, Bart | author-link = Bart Kosko | url-access = registration | url = https://archive.org/details/noise00kosk }}
- Urban, Felix (2016). Investigating sonic empowerment in urban cultures. Baden-Baden, Tectum. {{ISBN|978-3-8288-3683-9}}
- {{cite book | title=Making Noise: From Babel to the Big Bang & Beyond | author=Schwartz, Hillel | author-link=Hillel Schwartz (historian)| publisher=Zone Books | location=New York | year=2011 | isbn=978-1-935408-12-3 }}
External links
{{Wiktionary}}
{{Wikiquote|Sound}}
{{Commons category}}
- [https://web.archive.org/web/20031127195212/http://www.who.int/docstore/peh/noise/guidelines2.html Guidelines for Community Noise, World Health Organization, 1999]
- [http://www.lindos.co.uk/cgi-bin/FlexiData.cgi?SOURCE=Articles Audio Measuring Articles – Electronics] {{Webarchive|url=https://web.archive.org/web/20160807014708/http://www.lindos.co.uk/cgi-bin/FlexiData.cgi?SOURCE=Articles |date=2016-08-07 }}
- [http://www.ieee.li/pdf/viewgraphs_mohr_noise.pdf Mohr on Receiver Noise: Characterization, Insights & Surprises]
- [http://www.sengpielaudio.com/calculator-noise.htm Noise voltage – Calculation and Measuring of Thermal Noise]
- [http://osha.europa.eu/topics/noise Noise at work] European Agency for Safety and Health at Work (EU-OSHA)
- [http://maperc.ucdenver.edu/ Mountain & Plains ERC: A NIOSH Education and Research Center for Occupational & Environmental Health & Safety]
- [https://www.cdc.gov/niosh/topics/noise/ US National Institute for Occupational Safety and Health], – Noise
- [https://web.archive.org/web/20061209222533/http://www.defra.gov.uk/environment/noise/research/climate/nannexb.htm European noise laws]
- [http://www.nonoise.org/ Noise Pollution Clearing House]
- [http://www.plm.automation.siemens.com/en/campaigns/single_topic.cfm?Component=253572&ComponentTemplate=186312 Introduction to the fundamentals of acoustic engineering]
{{Noise}}
{{Timbre}}
{{Authority control}}