Noise Abatement and Control: The Federal Role

Noise Abatement and Control:
The Federal Role
David M. Bearden
Specialist in Environmental Policy
Resources, Science, and Industry Division
Community perceptions of increasing exposure to noise from a wide array of
sources have raised questions about the role of the federal government in regulating
noise, and the adequacy of existing standards. The role of the federal government in
regulating noise has remained fairly constant overall since the enactment of the Noise
Control Act in 1972 (P.L. 92-574). With authorities under this and other related
statutes, the federal government has established, and enforces, standards for maximum
sound levels generated from aircraft and airports, federally funded highways, interstate
motor carriers and railroads, medium- and heavy-duty trucks, motorcycles and mopeds,
workplace activities, and portable air compressors. The federal government also
regulates human exposure to noise in federally funded housing. In more recent years,
the federal role has expanded to include regulation of noise generated by human
activities on public lands, including National Parks. State and local governments
determine the extent to which other sources of noise are regulated, including
commercial, industrial, and residential activities. Although noise standards generally
provide a level of protection sufficient to prevent human hearing loss, they vary among
individual sources in terms of what level of sound is permissible. This report explains
potential effects of various sound levels, describes the role of the federal government in
regulating noise, characterizes existing federal standards, discusses the role of state and
local governments, and examines relevant issues.
According to the National Institute on Deafness and Other Communication
Disorders, exposure to loud sounds is responsible for hearing impairment in 10 million
of the nearly 30 million people with hearing loss in the United States, and another 30
million people are daily exposed to dangerous noise levels. Many individuals are also
regularly exposed to sound levels that may not lead to hearing loss, but can be intrusive
and impair one’s quality of life. Several federal laws require the federal government to
maintain standards for various sources of noise. However, the standards do vary in
stringency among individual sources. Although there is some variance among the

standards, all of them limit sound levels at least to a degree that would prevent human
hearing loss.
The responsibility for setting and enforcing noise control standards is divided among
multiple federal agencies. In the past, the Environmental Protection Agency (EPA)
coordinated all federal noise control activities through its Office of Noise Abatement and
Control. However, Congress phased out the office’s funding in FY1983 as part of a shift
in federal noise control policy to transfer the primary responsibility for regulating noise
to state and local governments. Although EPA no longer plays a prominent role in
regulating noise, its past standards and regulations remain in effect, and other federal
agencies continue to set and enforce noise standards for sources within their regulatory
Public interest in the federal regulation of noise and the adequacy of existing
standards continues to be strong, especially among communities where sources of noise
have proliferated, and as residential development has resulted in people living closer to
sources of noise. Considering that existing standards generally are protective against
hearing loss, the primary concern among the public has been whether the standards should
be tightened to protect the quality of life in communities where sound levels may be
perceived as annoying or intrusive, but not necessarily harmful to human hearing.
Potential effects of various sound levels, and the roles of federal, state, and local
governments in regulating individual sources of noise, are discussed below.
How Loud Is Too Loud?
Sound is measured in units of decibels (dbA), and an increase of 10 dbA represents
sounds that are perceived to be twice as loud. There is broad consensus among regulators
in the United States that constant or repeated exposure to sound levels in the vicinity of
90 dbA and higher can lead to hearing loss. Exposure to sounds significantly below these
levels are generally not considered harmful to human hearing. However, most individuals
perceive unwanted sound above 65 dbA to be intrusive, which can impair one’s quality
of life, depending on the sensitivity of the individual and the frequency and duration of
exposure. Some also argue that persistent exposure to intrusive sound may have certain
physiological effects, such as headaches or nausea, even though one’s hearing ability may
not be impaired. There also have been some questions about the vibration-induced effects
of low frequency sound, which can be felt but not heard.
What Sources of Noise Are Subject to Federal Regulation?
The Noise Control Act of 1972 (P.L. 92-574) and several other federal laws require
the federal government to set and enforce noise standards for aircraft and airports,
interstate motor carriers and railroads, workplace activities, engines and certain types of
equipment, federally funded highway projects, and federally funded housing projects. The
Noise Control Act also requires federal agencies to comply with all federal, state, and
local noise requirements. Various federal laws and regulations governing the
administration of park and recreational lands owned by the federal government also
provide authorities for agencies to regulate noise that would be generated from human
activities on, and in the vicinity of, these lands.

Most federal noise standards focus on preventing hearing loss by limiting exposure
to sounds of 90 dbA and higher. Some federal standards are stricter and focus on limiting
exposure to lower levels of around 65 dbA to protect quality of life. Whether “quality-of-
life” standards should be tightened has been an ongoing issue, particularly among
communities located near transportation sources such as airports and highways, where
exposure to noise is a daily or routine occurrence. As noted above, there also have been
some questions about the effects of low frequency sound, but so far, noise standards in
the United States have not regulated low frequency sound below the threshold of human
hearing. Major existing federal standards that regulate human exposure to noise, and the
agencies responsible for setting and enforcing them, are discussed below.
Aircraft and Airports. The Aircraft Noise Abatement Act of 1968 (P.L. 90-411)
requires the Federal Aviation Administration (FAA) to develop and enforce standards for
aircraft noise.1 In developing these standards, the FAA generally follows noise limits
recommended by the International Civil Aviation Organization (ICAO). Federal noise
regulations define aircraft according to four noise classes: Stage 1, Stage 2, Stage 3, and
Stage 4. Stage 1 aircraft are the loudest, and Stage 4 are the quietest. All Stage 1 aircraft
have been phased out of commercial operation, and all unmodified Stage 2 aircraft over
75,000 pounds were phased out by December 31, 1999, as required by the Airport Noise
and Capacity Act of 1990 (P.L. 101-508, Title IX, Subtitle D).2 Stage 3 aircraft must meet
separate standards for runway takeoffs, landings, and sidelines, ranging from 89 to 106
dbA depending on the aircraft’s weight and its number of engines.3 Stage 4 standards are
stricter and require a further reduction of 10 dbA overall relative to Stage 3 standards.
The Stage 4 standards are relatively new and are based on standards that the ICAO
adopted in June 2001 (referred to as “Chapter 4” in ICAO parlance). The FAA finalized4
these standards in July 2005, adopting the ICAO standards by reference. The Stage 4
standards apply to newly manufactured subsonic jet airplanes, and subsonic transport
category large airplanes, for which a new design is submitted for airworthiness
certification on or after January 1, 2006. As the majority of jet aircraft designed in recent
years are already quiet enough to attain the Stage 4 standards, some have commented that
the impact of the stricter standards on most aircraft manufacturers may be less significant
than otherwise. The ICAO also had recommended separate standards for propeller-
driven, small airplanes. The FAA finalized these standards in January 2006.5 They apply
to newly manufactured, propeller-driven, small aircraft for which a new design is
submitted for airworthiness certification on or after February 3, 2006.
In addition to aircraft certification standards, airports receiving federal funds are
required to meet noise control standards for their operation. The standards range from 65
dbA for airports adjacent to residential areas to over 85 dbA for those adjacent to lands

1 49 U.S.C. 44715.
2 49 U.S.C. 47528.
3 14 C.F.R. 36.
4 70 Federal Register 38742.
5 71 Federal Register 528.

used for agricultural and transportation purposes.6 The Airport and Airway Improvement
Act of 1982 (P.L. 97-248) established the Airport Improvement Program (AIP) to provide
federal assistance for airport construction projects and to award grants for mitigating noise
resulting from the expansion of airport capacity. Airport operators applying for such
grants must design noise exposure maps and develop mitigation programs to ensure that
noise levels are compatible with adjacent land uses.
Interstate Motor Carriers. The Noise Control Act required EPA to develop noise
standards for motor carriers engaged in interstate commerce, and it authorized the Federal
Highway Administration to enforce them.7 All commercial vehicles over 10,000 pounds
are subject to standards for highway travel and stationary operation, but the standards do
not apply to sounds from horns or sirens when operated as warning devices for safety8
purposes. For highway travel, the standards range from 81 to 93 dbA, depending on the
speed of the vehicle and the distance from which the sound is measured. The standards
for stationary operation are similar and range from 83 to 91 dbA, depending on the
distance from the vehicle. The standards apply at any time or condition of highway grade,
vehicle load, acceleration, or deceleration.
Interstate Railroads. The Noise Control Act required EPA to establish noise
standards for trains and railway stations engaged in interstate commerce, and the law
authorized the Federal Railroad Administration (FRA) to enforce those standards.9 There
are separate standards for locomotives, railway cars, and railway station activities such
as car coupling.10 For locomotives built before 1980, noise is limited to 73 dbA in
stationary operation and at idle speeds, and is limited to 96 dbA at cruising speeds. The
standards for locomotives built after 1979 are stricter, and limit noise in stationary
operation and at idle speeds to 70 dbA and at cruising speeds to 90 dbA. Noise from
railway cars must not exceed 88 dbA at speeds of 45 miles per hour (mph) or less, and
must not surpass 93 dbA at speeds greater than 45 mph. Noise from car coupling
activities at railway stations is limited to 92 dbA.
There are no uniform noise standards that control sounds from locomotive horns,
whistles, or bells when they are operated as warning devices for safety purposes.
However, in response to concerns about noise from horns in communities located near
railways, the FRA finalized regulations in 2005,11 and modified them in 2006,12 allowing
such communities to designate “quiet zones.” Within these zones, communities could
prohibit the routine sounding of locomotive horns. Designation of these zones is subject
to certain conditions, including that there would be no significant risk of loss of life or
risk of serious personal injury resulting from the lack of a horn sounding.

6 14 C.F.R. 150.
7 42 U.S.C. 4917.
8 49 C.F.R. 325.
9 42 U.S.C. 4916.
10 49 C.F.R. 210.
11 70 Federal Register 21844.
12 71 Federal Register 47614.

Workplace Activities. The Occupational Safety and Health Act of 1970 (P.L. 91-

596) required the Occupational Safety and Health Administration (OSHA) to develop and13

enforce safety and health standards for workplace activities. To protect workers, OSHA
established standards which specify the duration of time that employees can safely be14
exposed to specific sound levels. At a minimum, constant noise exposure must not
exceed 90 dbA over 8 hours. The highest sound level to which workers can constantly
be exposed is 115 dbA, and exposure to this level must not exceed 15 minutes within an
8-hour period. The standards limit instantaneous exposure, such as impact noise, to 140
dbA. If noise levels exceed these standards, employers are required to provide hearing
protection equipment to workers in order to reduce sound exposure to acceptable limits.
In April 2007, the Department of Labor proposed regulations that would require minors
to wear hearing protection devices when working with wood processing machinery.15
Engines and Certain Types of Equipment. The Noise Control Act directed
EPA to set and enforce noise standards for motors and engines, and transportation,
construction, and electrical equipment.16 With this authority, EPA established standards
for motorcycles and mopeds, medium and heavy-duty trucks over 10,000 pounds, and
portable air compressors. The standards for motorcycles only apply to those manufactured
after 1982 and range from 80 to 86 dbA, depending on the model year and whether the
motorcycle is designed for street or off-road use.17 Noise from mopeds is limited to 70
dbA. The standards for trucks over 10,000 pounds only apply to those manufactured after
1978 and range from 80 to 83 dbA depending on the model year.18 These standards are
separate from those for interstate motor carriers. Noise from portable air compressors is
limited to 76 dbA.19
Federally Funded Highway Projects. The Federal-Aid Highway Act of 1970
(P.L. 91-605) required the Federal Highway Administration (FHWA) to develop standards20
for highway noise levels that are compatible with adjacent land uses. The law prohibits
the approval of federal funding for highway projects that do not incorporate measures to21
attain these standards, which range from 52 to 75 dbA depending on adjacent land use.
Among the most common method to attain these standards is to erect a physical barrier
(i.e., a noise wall) between the highway and the adjacent land.
Federally Funded Housing Projects. Under general authorities provided by
the Housing and Urban Development Act of 1968 (P.L. 90-448), the Department of
Housing and Urban Development (HUD) has established standards for federally funded

13 29 U.S.C. 655.
14 29 C.F.R. 1910.95.
15 72 Federal Register 19337.
16 42 U.S.C. 4905.
17 40 C.F.R. 205, Subparts D and E.
18 40 C.F.R. 205, Subpart B.
19 40 C.F.R. 204.
20 23 U.S.C. 109(i).
21 23 C.F.R. 772.

housing projects located in noise-exposed areas.22 The standards limit interior noise to
a daily average of 65 dbA.23 Possible methods to mitigate noise in housing include the
installation of doors and windows designed to diminish the transmission of sound, the
insertion of noise-blocking insulation within walls, and the use of thicker walls and floors
in new construction.
Federal Park and Recreational Lands. Various federal laws and regulations
governing the administration of park and recreational lands owned by the federal
government also provide authorities for agencies to regulate noise that would be generated
from human activities on, and in the vicinity of, these lands. For example, the National
Park Service has included noise standards in its regulations governing the operation of
vessels on waters within all National Parks.24 Certain regulations also govern noise from
specific sources in particular parks and recreational areas. For example, the FAA has
promulgated regulations limiting noise from aircraft operations in the vicinity of Grand25
Canyon National Park. These and other restrictions have been motivated by rising
interest among recreational users in maintaining the serene qualities of public lands for
their enjoyment. However, there have been conflicting desires between recreational users
who seek a quieter environment and those users whose preferred recreational activities
would be restricted because of the noise those activities would generate.
Noise Reduction Devices. The federal government also is responsible for rating
consumer devices designed to be worn by individuals to reduce exposure to potentially
harmful or intrusive sound levels. The Noise Control Act authorized EPA to require
labels for products that reduce noise.26 Under this authority, EPA established Noise
Reduction Ratings for noise reduction devices, such as head gear and ear plugs.
Manufacturers are required to use these ratings to identify the reduction of sound in
decibels that the user would experience when wearing these devices.27
What Is the State and Local Role in Controlling Noise?
The federal role in regulating noise is primarily limited to transportation, workplace
activities, certain types of equipment, and human activities on public lands owned by the
federal government. State and local governments determine the extent to which other
sources of noise are controlled, and regulations for such sources can vary widely among
localities. Further, some states do not directly regulate noise, but allow local governments
to play the primary role. Sources of noise commonly regulated at the state and local level
include commercial, industrial, and residential activities. Regulations for such sources
typically control the public’s exposure to noise by limiting certain activities to specific
times, such as construction noise only during business hours. Public concern about
differing state and local control of noise has led some to suggest that the federal role
should be expanded to regulate a greater variety of sources uniformly across the country.

22 42 U.S.C. 3535(d).
23 24 C.F.R. 51, Subpart B.
24 72 Federal Register 13694.
25 70 Federal Register 16084.
26 42 U.S.C. 4907.
27 40 C.F.R. 211.