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Noise regulation includes statutes or guidelines relating to sound transmission established by national, state or provincial and municipal levels of government. After the watershed passage of the United States Noise Control Act of 1972, other local and state governments passed further regulations. A noise regulation restricts the amount of noise, the duration of noise and the source of noise. It usually places restrictions for certain times of the day. Although the United Kingdom and Japan enacted national laws in 1960 and 1967 respectively, these laws were not at all comprehensive or fully enforceable as to address generally rising ambient noise, enforceable numerical source limits on aircraft and motor vehicles or comprehensive directives to local government. Quiet hours are times during a day or night when there are placed tighter restrictions on unnecessary or bothersome noise. They vary between jurisdictions and areas, but are typically in place during night time, for example between 23:00 and 07:00, so as not to interfere with residents sleep. Some noise measurement standards which takes into account different times of the day are the American day night average sound level (Ldn) standard or the European day–evening–night noise level (Lden) standard. Some jurisdictions also have wider noise restrictions in the weekends or on certain public holidays. Industrial or nightlife areas may be exempt or have fewer restrictions, while private institutions, hotels and universities may place additional restrictions on their guests.

In the 1960s and earlier, few people recognized that citizens might be entitled to be protected from adverse sound level exposure. Most concerted actions consisted of citizens groups organized to oppose a specific highway or airport, and occasionally a nuisance lawsuit would arise. Things in the United States changed rapidly with passage of the National Environmental Policy Act (NEPA) in 1969 and the Noise Pollution and Abatement Act, more commonly called the Noise Control Act (NCA), in 1972. Passage of the NCA was remarkable considering the lack of historic organized citizen concern. However, the United States Environmental Protection Agency (EPA) had testified before Congress that 30 million Americans are exposed to non occupational noise high enough to cause hearing loss and 44 million Americans live in homes impacted by aircraft or highway noise. NEPA requires all federally funded major actions to be analyzed for all physical environmental impacts including noise pollution, and the NCA directed the EPA to promulgate regulations for a host of noise emissions. Many city ordinances prohibit sound above a threshold intensity from trespassing over property line at night, typically between 9 p. m. to 7 a. m., and during the day restricts it to a higher sound level; however, enforcement is uneven. Many municipalities do not follow up on complaints. Even where a municipality has an enforcement office, it may only be willing to issue warnings, since taking offenders to court is expensive. A notable exception to this rule is the City of Portland, Oregon, which has instituted an aggressive protection for its citizens with fines reaching as high at $5000 per infraction, with the ability to cite a responsible noise violator multiple times in a single day. Under the Occupational Safety and Health Act of 1970, employers are responsible for providing safe and healthful workplaces for their employees. OSHA's role is to ensure these conditions for America's working men and women by setting and enforcing standards, and providing training, education and assistance. The same Act charges the National Institute for Occupational Safety and Health (NIOSH) with recommending occupational safety and health standards. NIOSH communicates these recommended standards to regulatory agencies (including OSHA) and to others in the occupational safety and health community through the publication and dissemination of Criteria Documents such as the Criteria for A Recommended Standard Occupational Noise Exposure.

Initially these laws had a significant effect on thoughtful study of transportation programs and also federally funded housing programs in the United States. They also gave states and cities an impetus to consider environmental noise in their planning and zoning decisions, and led to a host of statutes below the federal level. Awareness of the need for noise control was rising. In fact, by 1973 a national poll of 60,000 U. S. residents found that sixty percent of people considered street noise to have a "disturbing, harmful or dangerous" impact. This trend continued strongly throughout the 1970s in the U. S., with about half of the states and hundreds of cities passing substantive noise control laws. The EPA coordinated all federal noise control activities through its Office of Noise Abatement and Control. The EPA phased out the office's funding in 1982 as part of a shift in federal noise control policy to transfer the primary responsibility of regulating noise to state and local governments. However, the Noise Control Act of 1972 and the Quiet Communities Act of 1978 were never rescinded by Congress and remain in effect today, although essentially unfunded. The Federal Aviation Administration (FAA) regulates aircraft noise by specifying the maximum noise level that individual civil aircraft can emit through requiring aircraft to meet certain noise certification standards. These standards designate changes in maximum noise level requirements by "stage" designation. The U. S. noise standards are defined in the Code of Federal Regulations (CFR) Title 14 Part 36 – Noise Standards: Aircraft Type and Airworthiness Certification (14 CFR Part 36). The FAA also pursues a program of aircraft noise control in cooperation with the aviation community. The Federal Highway Administration (FHWA) developed noise regulations to control highway noise as required by the Federal Aid Highway Act of 1970. The regulations requires promulgation of traffic noise level criteria for various land use activities, and describe procedures for the abatement of highway traffic noise and construction noise. Nevertheless, some states continued to act. California carried out an ambitious plan to require its cities to establish a "Noise Element of the General Plan," which provides guidance for land planning decisions to minimize noise impacts on the public. Many cities throughout the U. S. also have noise ordinances, which specifies the allowable sound level that can cross property lines. These ordinances can be enforced with local police powers.

Japan actually passed the first national noise control act, but its scope was much more limited than the U. S. law, addressing mainly workplace and construction noise.

Several European countries emulated the U. S. national noise control law: Netherlands (1979), France (1985), Spain (1993), and Denmark (1994). In some cases unlegislated innovations have led to quieter products exceeding legal mandates (for example, hybrid vehicles or best available technology in washing machines). Environmental noise is a special definition in the European directive 2002/49/EC article 10.1.

Local ordinances are principally aimed at construction noise, power equipment operated by individuals and unmuffled industrial noise penetrating residential areas. Thousands of U. S. cities have prepared noise ordinances that give noise control officers and police the power to investigate noise complaints and enforcement power to abate the offending noise source, through shutdowns and fines. One obligation of a community is to protect its citizens from adverse environmental influences. Noise is one of these factors, Noise has documented effects on people, they can be divided into three types. The first type is a physical effect that directly and adversely effects a person's health. Hearing loss and vibration of bodily components are examples. The second type is a physiological effect that adversely effects a person's health; heightened blood pressure and general stress response are examples. The third type is psychological that adversely effects a person's welfare; examples are distraction, annoyance, and complaint. The only feasible legal basis for a community's right to control noise is based on these adverse health and welfare effects. It is clearly easier to uphold the constitutionality of a noise ordinance in a court of law if it can be shown that it is based on health and welfare concerns. The following is a short list of recognized effects of noise that can be addressed as a reason for a noise ordinance. Excess non Occupational noise exposure, hearing loss on both public and private property, speech interference on both public and private property, audio interference on both public and private property, and sleep interference on mostly private property.

There are several fundamental issues that shape the legality, effectiveness and enforceability of any community noise regulation.

The federal government has preempted certain areas of noise regulation. They can be found in the Code of Federal Regulations under the EPA Noise Abatement Programs; Parts 201 to 205 and 211 cover railroads, motor carriers in interstate commerce, construction equipment, and motor vehicles. They require product labeling and prohibit tampering with noise control devices. Communities may enact regulations that are no more strict than the federal ones so that local enforcement can be carried out. They can enact curfews and restrict vehicle use in established zones such as residential. Any restriction on interstate motor carriers or railroads may NOT be for the purpose of noise control. States have police powers granted by the Constitution. They may also enact regulations that are no more strict than federal regulations. They may also preempt local ordinances. California and New Jersey have comprehensive noise codes that communities must meet. Many states required that local ordinances be no more strict than the state code whether such code exists or not. One relatively common preemption is protection of shooting ranges from noise regulation or litigation and right to farm laws that protect agricultural areas from nuisance litigation by encroaching residential areas.

In one Supreme Court case the court ruled that the specificity of the city ordinance regulating school verbal protests was not constitutionally vague, gave fair warning, and was not an invitation to arbitrary enforcement and so was not overbroad, despite the implied limitation on free speech.

Nuisance law applies to both community noise regulation as well as private suits brought to court to reduce noise impact.

Care must be taken in writing a subjective noise provision so that it overcomes the objections listed above. Care must be taken when writing an objective noise provision to make sure that the sound levels are physically realizable. For example, requiring the maximum sound level of an automobile to be 40 dB(A) or the maximum sound level in a residential zone to be 30 dB(A) opens the provision to an enforceability challenge.

Many communities have definitions that are local to them, such as those defining motor vehicles and sound levels and sound level measurements. Some that have been added to make noise enforcement more specific are listed here.

This provision can be both a subjective immission control and an objective emission control. Normally there are daily curfews and in some case weekend curfews. The subjective aspect is to prevent noise disturbance in the adjacent community. The objective aspect is to control the sound output of specific machines. There are four major sources of site noise: (1) direct sound from continually operating equipment such as air compressors; (2) intermittent sound from equipment such as jack hammers;(3)backup alarms; and (4) hauling equipment such as trucks. Air compressor noise is regulated by CFR 204 and backup alarms are regulated by CFR 1926. Boston, MA(Section 16–26.4) permits construction on weekdays between 7am and 6 pm. Madison, WI (Chapter 24.08) limits sound levels to 88 dB(A) at 50 Feet. Miami, FL (Section 36 6) considers the noise a noise disturbance if it occurs between 6pm and 8am during the week and any time on Sunday. Dallas, TX (Section 30 2 (9)) permits construction in residential zones from 7am to 7pm on weekdays, from 9am to 7pm on Saturdays and Holidays, and prohibits construction on Sundays. Albuquerque, New Mexico (Section 9 9 8) has a more complex control. It prohibits construction and demolition within 500 feet of noise sensitive properties (residences included) if the equipment sound control devices are less effective than the original equipment and if noise mitigation measures are not used when the levels exceed 90 dB (weighting not specified) or more than 80 dB during the day for three days.

This provision is a subjective immission control with a curfew. It is used in residential zones as well as in commercial areas abutting residential zones. Portland, OR (Title 18.10.030) has several ways to handle these tools. They separate outdoor and indoor use to different maximum levels at the property line. They have a night curfew and separate 5 HP tools from higher powered tools. Madison WI (Chapter 24.08) has similar HP restrictions. Albuquerque, NM (Title 9 9 7) restricts locations to more than 500 feet from residential and noise sensitive zones. Dallas, TX(Sec. 30 2) exempts lawn maintenance tools during daylight hours. Green Bay, WI (Subchapter II – 27.201) exempts snow removal tools.

This provision is a subjective immission control with a curfew. It is for impulsive sound sources that are not associated with construction activities or shooting ranges. Many communities use the Maximum Permissible Sound Levels criterion (see below), with a correction for the character of the sound. Illinois sets maximum blasting levels by land use zone and in three time categories. Portland, OR (Section 18.10.010. F) limits levels to 100 dB (peak) from 7am to 10pm and 80 dB (peak) from 10pm to 7 am.

Hydraulic Fracturing operations generate site sound as well as vehicle sound and several different provisions are required to control it. Federal law regulates the levels of certain site machinery. A subjective immission control or an objective immission control can be applied to surrounding neighborhoods. See maximum Permissible Sound Levels. Motor vehicle sound is mostly off site so vehicle noise regulations are applicable. See Motor Vehicles on a Public Right of way. The State of New York has announced a statewide ban on such operations. Buffalo, NY and Pittsburgh, PA have announced a ban. Colorado has numerous activities to stop fracking.

This is a subjective emission control to reduce the excessive shouting and protests that can surround funeral proceedings. It makes use of the plainly audible term and so adds a distance criterion. There are certain groups, particularly those that object to involvement in foreign wars, who believe it is an obligation to disrupt and picket funerals, especially those of deceased military veterans. This provision must not infringe on Constitutionally protected free speech. Illinois h(720 ILCS 5/26 6)has a comprehensive provision covering more aspects of this event than noise. They failed to use “plainly audible” which is narrower than “audible”. Utah(Section 76 9 108) restricts disruptive activity to beyond 200 feet.

This provision is a subjective immission control with a curfew. Operations in commercial facilities can impact adjacent residential zones. Los Angeles, CA (Section 114.03) places a curfew on such operations between 10pm and 7am but only if the source is within 200 feet of a residence. Chicago, IL (Section 11 4 2830) permits night operations unless they create a noise disturbance. Hammond, IN (Section 6.2.6) prohibits noise disturbance between 7pm and 7am.

This provision is an objective immission control. It requires the measurement of sound levels at or beyond a property line and its vertical extension. There are several methods for implementing such a provision:
It may not permit any exceedence or may permit exceedence only for a percentage of the measurement period. It may require the measurement method to be instantaneous, such as dB(A) or time averaged, such as Energy Equivalent Level (Leq). It may be a fixed level limit, such as 55 dB(A), or it may be a level relative to the ambient sound, such as 5 dB(A) above the ambient. It may require measurement of the frequency spectrum, such as one octave bands, or A weighting, such as dB(A). It may define different maximum levels based on zoning criteria, such as residential, commercial, or industrial. It may define different maximum levels based on time of day or day of week, such as reduced maxima during night hours or on weekends. It may require reduction of maximum levels based on the character of the sound, such as intermittent or impulsive. It may exempt certain classes of sound sources, such as shooting ranges, farm equipment, emergency equipment, railroads, or licensed activities. Most noise ordinances set maximum levels for two time periods: Day (7am to 10pm) and Night (10pm to 7am). San Diego (Article 9.25)sets three periods: Day (7am to 7pm), Evening (7pm to 10pm), and Night (10pm to 7am) and exempts industrial zones from time based restrictions. Seattle, WA (Chapter 25.08) sets two time periods but changes 7am to 9am on weekends and holidays. Several states have maximum permissible land use sound levels in dB(A). Most have Day and Night periods and three use categories: residential, Commercial and Industrial. Washington (Chapter 70.107) sets maximum levels in dB(A) but allows 5 dB(A) more if the sound is only 15 minutes in an hour, or 10 dB(A) for 5 minutes in an hour. Numerous cities have fixed levels, permitting excess levels for short times (e. g., Dallas, TX, Chapter 30) while others use Leq (Lincoln, NE, Chapter 8.24). Los Angeles, CA (Chapter XI) uses a relative level with a stated but presumed ambient. New York City, NY (Chapter 19) requires Leq measurements to be made over one hour. Atlanta, GA limits impulsive sound to 100 dB(C) at property lines, while most reduce the maximum level by 5 dB for pure tones and impulsive sounds.

This provision is a subjective immission control with a curfew. If the activity is done in a residential zone, the Domestic Tools provision can be applied for the repairs, but this provision also is used for the testing phase of any repairs. Los Angeles, CA (Section 114.01) covers this violation in three ways. The first is application of the noise disturbance provision in residential districts between the hours of 8 pm to 8 am. The second is being plainly audible at a distance of 150 feet or more in residential districts between the hours of 8 pm to 8 am. The third is exceeding the presumed ambient by 5 dB. Hammond, IN (Section 6.2.7) prohibits this activity as a noise disturbance at any time.

This provision is a subjective immission control. This provision is generic in that it covers all events that are considered disturbing by a listener, with or without measurement. The strength of this provision is that it covers situations not contemplated in a noise ordinance and can be used as backup for more specific provisions. The weakness is that it may not give fair warning, may lead to arbitrary enforcement on the part of the regulator, or permit unreasonable demands by a listener.

This provision is a subjective immission control. It is used to reduce levels of both stationary and vehicular sound sources around hospitals, schools, and other noise sensitive locations. To provide fair warning visible signs must be posted. It is possible to have an extensive list. For example, if churches are on the list and the community has many of them, signage, compliance, and enforcement can be a problem. In modern hospital environments, helicopter sound is exempt.

This provision is an objective immission control. It regulates the site of the sound source while the Sound Reproduction Devices section regulates the devices that create the sound. It can regulate the sound levels received by involuntary listeners in the surrounding community as well as the sound levels received by voluntary listeners. If the latter aspect is incorporated, limiting internal sound levels often resolves community noise impact. Los Angeles (Article 2, Section 112.06)requires warning signs and limits noise exposure to 95 dB(A) at any position normally occupied. Seattle, WA {Section 25.08.501} considers the sound emitted to be in violation if the sound is plainly audible within a dwelling from 10 pm to 7am; the need for a sound level meter is avoided. Chicago, IL {Section 11 4 2805} limits received sound levels to 55 dB(A) inside a residential dwelling unit but if the ambient is greater, the limit is 65 dB(A). If outdoors, the limit is conversational level at 100 feet from the property line. If the building is set back 20 feet from the property line, the allowable level is 84 dB(A)! Both of Chicago's limits apply from 10 pm to 8 am. Salt Lake health Department, UT {Section 4.5.11. (vii)} sets the limit at 95 dB(A) at a position that would normally be occupied by a patron and 100 dB(A) at other positions. They also require a sign stating WARNING: SOUND LEVELS ON THIS PREMISE [sic] MAY CAUSE PERMANENT HEARING DAMAGE. HEARING PROTECTION IS AVAILABLE. Anchorage, AK (Section 15.70.060. B.12) sets maximum levels for any patron at 90 dB(A).

This provision is a subjective immission control with a curfew. It has been used to regulate the sound of model aircraft on both private and public property. It applies to airborne, water borne, and land borne, unmanned vehicles. It makes no distinction between model vehicles and full size unmanned vehicles. it applies also to the engines of those vehicles. Most regulations pertained to private unmanned vehicles, normally restricted to local open fields. The development of drones with microphones, cameras and GPS has opened the door to commercial use over wider private and public properties. Since federal preemption of drone use will likely occur, it is important for this provision to make the distinction. Salt Lake Health Department (Section 4.5.15) limits activity to 800 feet from a dwelling between 10 pm and 7 am, or if it cases a noise disturbance. Atlanta, GA (Section 74 136(b)) uses the plainly audible criterion across a residential property line, on a public property from 10 pm to 7 am on weekdays or from 10 pm to 10 am on weekends or holidays for any sound source.

This provision is a subjective immission control with a curfew. A propane cannon is used to keep animals and birds from destroying commercial crops. In large fields, many are used and fired as frequent intervals. The sound levels are equivalent to the firing of a small artillery cannon. The provision may contain requirements that limit the number of cannons permitted in a specific area and the number firings per hour for each cannon. Many US states have a Right to Farm Act that limits nuisance litigation. Florida stated that it was a purpose of their act to protect reasonable agricultural activities conducted on farm land from nuisance suits. They also added a section that limited expand of operations without consideration of noise. Fairfax County, VA (Sections 105 4 4 and 108 5 1) require agricultural operation to meet maximum land use regulations and prohibit unnecessary noise. British Columbia Ministry of Agriculture (Farm Nuisance Noise document) have developed a comprehensive set of rules for cannon use.

This provision is a subjective immission control. It can contain a plainly audible term or a curfew. It is applied to commercial facilities using a sound system to deliberately propagate mostly speech, but also music. Most cities have provisions relevant to this subject. Lakewood, CO (Sections 9.52.06 and 09.52.160) used plainly audible as a regulatory tool and prohibits the sounding of bells, or chimes from 10pm to 7am. Charlotte, NC (Section 15 69(a)(4)) limits levels to 60 dB(A) at 50 feet from 9am to 9pm and 50 dB(A) at other times. Indianapolis, IN (Section 391 505) addresses broadcasts from aircraft. Connecticut (Section 22a 69 1.7) exempts bells, carillons, and chimes from religious facilities.

This provision is subjective immission control. It may contain a numerical level or a plainly audible term and a curfew. it is applied to specific sources of sound as opposed to any location at which the sound is created. It is applied primarily to amplified sound sources. Older provisions listed several items such as televisions, phonographs, etc. Changing the title to the above addresses the real issue and allows for novel sound production devices. Numerous communities have provisions for these devices; many use plainly audible as the criterion, such as Omaha, NE (Section 17 3) and Buffalo NY (Section 293 4)

This provision can be either a subjective or objective immission control with a curfew. The subjective aspect relates to noise disturbance in the local community. The objective aspect limits the acceptable sound level in the local community. Illinois (Environmental Protection Act 415.25) exempts certain stadiums and exempts festivals, parades, or street fairs. Colorado Spring, CO (Section 9.8.101) has similar exemptions, but limits the sound levels to 80 dB(A) at residential locations.

This provision is an emission control with a list of devices that are exempt. It can have a term that limits the time periods in which emergency alarms may be tested. It can have a term that limits the activation time of burglar or fire alarms. Chicago, IL (Section 11 4 2815) limits the time for tests to 4 minutes between 9am and 5pm. Oregon (Chapter 467) prohibits sound when an emergency vehicle is stationary.

This provision is an emission control that limits the activation period of alarms and restricts activation to a specific time of day or day of week. Los Angeles, CA prohibits the sounding if the signal can be heard at 200 feet or more. Chicago, IL (Section 11 4 2820) considers the sound to be a noise disturbance in residential areas if the sound exceeds 5 minutes in any hour; steam whistles are exempt. Albuquerque, NM (Section 9 9 12) restricts levels to 5 dB over the ambient at a property line and applies maximum permissible residential level as well as plainly audible restrictions at night.

This provision is a subjective immission control with a curfew. Boston, MA (Section 16–2.2) prohibits street sales near schools or churches if there is a “disturbance of the peace”. Hammond, IN (Section 6.2.4) places a curfew between 6 pm and 9 am.

This provision prevents the modification of muffling devices that increase the emitted sound. It can also be used to prevent the commercial sale of such mufflers. Most states and communities have prohibitions on tampering with noise reduction devices. whether stationary or moving. Salt Lake County health Department (Section 4.5.10) prohibits modifications of mufflers that increase sound levels and prohibits tampering with noise rating labels. See Section below on Adequate Mufflers.

This provision is a subjective emission control. Noise disturbance caused by vibration comes in three forms. One is contact with vibrating surfaces, the second in auditory, and the third is the observation of surrounding objects movement. Objectively regulating vibration is difficult so this provision makes use of the Vibration Perception Threshold. Railroad caused vibration is preempted by federal law (CFR 201). Chicago, IL (Section 11 4 2910) uses the perception threshold method. Dallas, TX requires measurement of low frequency vibration. Maryland uses the definition of noise to include sound and vibration at sub audible frequencies.

The sound created by wind turbines is caused by the blade rotation similar to aircraft propellers. Because the rotation rate is low, the frequency is also low, but the large size of many can result in disturbing sound levels, particularly in high wind areas. Most local control is done by advantageous site planning. New Hampshire (Title LXIV, Section 674:63) sets a sound level limit of 55 dB when measured at the site property line, allowing for exceptional events, such as storms. Studies have declared that wind noise can have a negative effect on health.

Stationary sources have fixed positions, so it is possible to define the listeners and therefore immission controls are appropriate. Motor vehicles are moving sources so it is not possible to define any specific listeners so emission controls are appropriate. There are exceptions to this distinction. Construction equipment, and some recreation vehicles, move within a bounded area and can be considered to be time varying fixed sources. Standing motor vehicles can radiate sufficient sound to create noise disturbance. These must be treated by specific provisions. The most common speed division is 35 mph.

This provision is a subjective emission control with only an operational time limit. Los Angeles, CA requires silencing in 5 minutes. New York City, NY (Section 24.221(d)) requires automatic shut off after 10 minutes and a prominent display of the local precinct number and telephone number. Boston, MA (Section 16–26.2) considers it a violation if the alarm is plainly audible at 200 feet and is on more than 5 minutes. Other states and communities have automatic shutoff times from 10 to 15 minutes. Some communities have banned such alarms.

This provision is a subjective immission control. It is based on the noise disturbance from drag racing and tire squealing on public rights of way. Illinois (625 ILCS 5/11 505) prohibits such activities. Hammond, IN (Section 6.2.14) prohibits such activity if it creates a noise disturbance.

Railroad activity is subject to federal regulations. Most communities do not attempt to regulate train sound. The level of train horns permitted by the Federal Railroad Administration sufficiently high that community impact occurs. One method to alleviate this sound is to have a community establish a quiet zone where the rail crossings meet federal safety standards so that horn use is not needed.

This provision is both an objective emission control and a subjective immission control with a curfew. It can apply to both public and private properties. Since these vehicles can move in large open areas, an objective control, limiting maximum sound levels at a fixed distance, is appropriate. Since they also can move in bounded areas near residences, a subjective control is appropriate. Numerous states and cities have emission controls measured at 50 feet; the most common level is 82 dB(A), which is similar to that for motor vehicles on public rights of way. Colorado Springs, CO (Section 9.8.204. C) requires a minimum distance of 660 feet from residences. Portland, OR (Section 18.10.020. C) requires the area must be designated for recreational vehicle use. Salt Lake health Department, UT (Section 4.5.10(x)) requires off highway vehicles to be at least 800 feet from a dwelling during the day and has a curfew from 10 pm to 7 am. They prohibit any noise disturbance and require sound levels to the less than 96 dB(A) at 50 feet.

This provision is both an objective emission control and a subjective immission control with a curfew. It can apply to both public and private properties. Since these vehicles can move in large open areas, an objective control, limiting maximum sound levels at a fixed distance is appropriate. Since they also can move in bounded areas near residences, a subjective control is appropriate. Numerous states and communities have objective controls; the most common maximum level is 78 dB(A). Federal law (36 CFR 2.18) regulates snowmobiles on federal property at 78 dB(A), so states and communities are free to regulate snowmobile sound levels on their property. Lincoln NE (Section 8.24.110) limits levels to 78 dB(A). Maine (Section 13112, Chapter 937) exempts snowmobiles at sanctioned racing events. Illinois (625 ILCS 40 Sec. 4 4)does also.

This provision is an objective emission control and a subjective control. It can place a maximum sound level at a specific distance for the loudest operation. It can set a curfew, or it can be based on noise disturbance in residential zones. Los Angeles, CA (Section 113.01) has a time limit that applies only within 200 feet of any residential building. Chicago, IL (Section 11 4 2900) considers any noise it a noise disturbance if the activity occurs between 8pm to 8am. Salt Lake City, UT (Section 4.5.6) considers it a noise disturbance if the activities occur between 10 pm to 7 am and closer than 800 feet from a dwelling. Atlanta, GA (Section 74 137(a)(5)prohibits collection between 9pm and am on a weekend day or legal holiday, except by permit. In Maryland, refuse collection is exempt during daytime hours and must meet maximum land use levels [55 dB(A)] in residential zones at night. Note in some areas garbage trucks themselves play music to let residents know it is time to bring out their garbage.

This provision is a subjective immission control. It sets a time limit on engine activity. It can also place a curfew on any engine activity. e. In Salt Lake City, UT (Section 4.5.10(xi)) it is considered a noise disturbance if the operation lasts more than 15 minutes. Dallas, TX (Section 30–3.1) applies the code to vehicles over 14,000 GVWR; they must be more than 300 feet from a residential zone and there is a 10 minute maximum. They also provide a list of idling vehicles that are exempt from prosecution such as buses or active concrete trucks. Hammond, IN (Section 6.2.10) limits operation to 3 minutes in an hour for vehicles over 14,000 GVWR in either public or private property. It exempts buses and taxis. Massachusetts allows idling no more than 5 minutes.

In the case of construction of new (or remodeled) apartments, condominiums, hospitals and hotels, many U. S. states and cities have stringent building codes with requirements of acoustical analysis, in order to protect building occupants from exterior noise sources and sound generated within the building itself. With regard to exterior noise, the codes usually require measurement of the exterior acoustic environment in order to determine the performance standard required for exterior building skin design. The architect can work with the acoustical scientist to arrive at the best cost effective means of creating a quiet interior (normally 45 dB). The most important elements of design of the building skin are usually: glazing (glass thickness, double pane design, etc. ), roof material, caulking standards, chimney baffles, exterior door design, mail slots, attic ventilation ports and mounting of through the wall air conditioners. A special case of building skin design arises in the case of aircraft noise, where the FAA has funded extensive work in residential retrofit. Regarding sound generated inside the building, there are two principal types of transmission. First, airborne sound travels through walls or floor/ceiling assemblies and can emanate from either human activities in adjacent living spaces or from mechanical noise within the building systems. Human activities might include voice, amplified sound systems or animal noise. Mechanical systems are elevator systems, boilers, refrigeration or air conditioning systems, generators and trash compactors. Since many of these sounds are inherently loud, the principle of regulation is to require the wall or ceiling assembly to meet certain performance standards (typically Sound Transmission Class of 50), which allows considerable attenuation of the sound level reaching occupants. The second type of interior sound is called Impact Insulation Class (IIC) transmission. This effect arises not from airborne transmission, but rather from transmission of sound through the building itself. The most common perception of IIC noise is from footfall of occupants in living spaces above. This type of noise is somewhat more difficult to abate, but consideration must be given to isolating the floor assembly above or hanging the lower ceiling on resilient channel. Commonly a performance standard of IIC equal to 50 is specified in building codes. California has generally led the U. S. in widespread application of building code requirements for sound transmission; accordingly, the level of protection for building occupants has increased markedly in the last several decades.

The U. S. Occupational Safety and Health Administration has established maximum noise levels for occupational exposure, beyond which mitigation measures or personal protective equipment is required. In recent years, Buy Quiet programs and initiatives have arisen in an effort to combat occupational noise exposures. These programs promote the purchase of quieter tools and equipment and encourage manufacturers to design quieter equipment.