Friday, July 19, 2024
Noise Basics

Sources of Noise

Noise pollution is unwanted or unnecessary sound that has detrimental impacts on human health, wildlife, and the environment. Noise pollution is common in many production facilities and other workplaces, but it also occurs in highway, rail, and airplane traffic, as well as outdoor construction activities (more info about noise pollution on

Noise on human health and the environment has become more apparent with each passing day, and the relevance of noise pollution as an environmental issue is being recognized. The first step to acknowledge this problem is to know the possible sources of noise emissions, in this article, we listed the major contributors of noise pollution in the environment.

1. Airplane Noise

Aircraft/ Airplane noise is the sound emission created by an aircraft or its components on the ground when parked, such as auxiliary power units, when taxiing, during take-off, beneath and lateral to departure and arrival directions, over-flying while on the route, or during landing.
A moving aircraft, like the jet engine or propeller, compresses and rarefies the air, causing air molecules to move. Pressure waves spread this flow through the air. Hearing is generated when these pressure waves are high enough and within the audible frequency range.

Health Effects

The main source of noise is aircraft engines, which can reach 140 decibels (dB) during takeoff. The engines and high-speed vibration over the fuselage are the primary sources of noise when the plane is in the air. There is no question that increased sound levels have health implications.
Hearing loss, hypertension, ischemic heart disease, irritation, sleep disturbance, and poor school success may all be caused by excessive occupational or other noise. Specifically, airport noise has been linked to high blood pressure and increases the risks of heart attacks.

Aircraft Management and Noise Reduction

Controlling where planes fly at takeoff and landing reduces noise emissions significantly. The location and usage of runways are critical; for instance, planes flying at night should travel overseas or lakes to minimize noise pollution. Thus, air traffic control plots flight paths to avoid the most heavily inhabited areas.
Furthermore, in efforts to lessen aircraft noise, Chapter 14, a revised noise control standard, was adopted by the International Civil Aviation Organization (ICAO)(official website), the United Nations’ intergovernmental body on aviation, in 2013. New aircraft models must be at least seven decibels quieter than those designed to the previous Chapter 4 requirement, according to the regulation. This means that future aircraft will use the quietest equipment available.

2. Backup Beepers

The use of tonal or ‘beeper’ type detectors on vehicles and mobile plants to provide warnings of moving plants on job sites is popular around the world. The alarms are intended to warn everyone who is in close proximity to the moving plant to take adequate safety precautions.
On construction sites, the sound from ‘beeper’ warnings is a frequent source of irritation for the local population. DECC (official website) and other regulators often receive noise complaints from ‘beeper’ alarms, especially when such alarms are used on night works.

Health Concerns

Beepers are at the forefront of or at the top of the list of road-building noise reports to government road builders. The standard frequency of 1000 Hz pure tone beeps at 97-112 decibels, which is far greater than the 70 decibel maximum for long-term hearing loss.
Brains have evolved to interpret ambient sounds that dissipate, rather than the repeated and constant sound of backup beepers. The sound is therefore annoying or painful, and it disrupts concentration and productivity.

Backup Beepers Mitigation

OSHA (official website) requires backup beepers or an observer for earth-moving vehicles with an obstructed view to the back and no one on the ground to help direct the pilot. “A reverse signal warning audible over surrounding noise level,” according to OSHA regulation 29 CFR Part 1926.601(b)(4), is needed only when the motor vehicle has “an obstructed vision to the rear.” The noise level will be depending on the employer.

Video: The Coolest Backup Beeper on an RVHauler White Noise Backup

3. Car Alarms

A car alarm is a nuisance that sounds constantly or intermittently and can disturb people in the community. It is also possible to argue that car alarms are unreliable. Car alarms are estimated to be false in 95 percent of cases, according to experts. Keyless entry devices, someone standing against the car, a loud truck, a car horn, a boom car — or a falling leaf — can all set off car alarms.

Car Alarm Noise Health Concern

Even at levels too low to inflict hearing loss, car noise exposure has a negative impact on public health, interfering with immune systems, learning, and sleep, raising stress hormones, and leading to cardiovascular diseases. If the extent of irritation is any indication, car alarms are one of the most dangerous noises.

Car Alarm Noise Mitigation

If you have a car alarm mounted, you are required by statute to ensure that it does not pose a disturbance to nearby residents. Ensure that the car alarm is installed by a qualified professional and that it has an electronic cutout that will silence it immediately after it has been triggered.
Check the alarm on a daily basis to ensure that it is all working well, and if it develops a malfunction, have it repaired right away.

Video: Why Obnoxiously Loud Car Alarms Aren’t As Common Today- Cheddar Explains

4. Dog Barking

Dogs naturally bark, but their excessive barking or whining can be really upsetting or distracting to your neighbors. Since this issue often happens while you are not at home, you might be unaware that there is a problem.
A barking dog may be considered a statutory noise nuisance’ under the statute. If you do nothing to stop the nuisance, you (as the owner) can be prosecuted under the Environmental Protection Act of 1990 (official website). A fine of up to $5,000 may be imposed.

Complaining About a Dog Barking

If a neighbor complains of your dog barking loudly, make your own inquiries and see if your dog is the source of the problem. The dog’s owner may not be aware that their dog is bothering you, but they will usually be willing to cooperate with you to resolve the issue.
If the problem persists, you may contact your local government to file a complaint under the Environmental Protection Act of 1990.

Mitigating Dog Barking Noises

Many sources of repetitive barking can be eliminated with compassion and common sense. A well-cared-for dog would not bark excessively to annoy the neighbors. In an enclosed backyard, dogs need enough room to walk about easily. A dog should not be chained for lengthy periods of time. A running leash can be used whenever a dog must be tied.

Video: Your dog has different kinds of barks — here’s why

5. Health Clubs

The World Health Organization (official website) considers noise emissions, a serious environmental concern in urban areas, to be a public health concern. This kind of pollution, which is one of the most prevalent environmental issues in cities, is a source of great annoyance and frequent complaints.
Instructors and students in fitness and medical centers are subject to elevated noise levels for multiple hours per day with no safety. Since noise impacts the entire body, one of the most significant consequences is the chance of hearing loss, which is a cause for concern for both mental and physical health.

Health Risk

Noise-induced hearing loss has also been an issue in health clubs. Club noise levels often surpassed those required for workplace noise exposure, according to a review of noise levels recorded during 125 aerobics courses. During aerobics lessons, average noise levels ranged from 78 to 106 dB(A), with 79 percent of readings exceeding 90 dB(A) or higher for 60 minutes.

Health Club Noise Mitigation

Participants and instructors in health clubs should be educated to raise their consciousness that loud noise levels can cause irreversible hearing loss and to discourage such loss from occurring.

Video: Loud deadlift? how to make it quieter, noise reduction

6. Helicopters

Helicopter operations around the world, especially in the United States, are causing public outcry about noise; in the last two to three years, large protests against helicopter use have occurred in New York and Los Angeles areas.
The level of helicopter traffic is disconcertingly higher today. According to the noise measurements in the NRDC (official website) survey, helicopters are much louder than jet planes. “The noise pollution from helicopters and ferry horns is unacceptable and excessive,” said Dean Flanagan, a Battery Park (official website) resident.

Health Risk

The noise of a helicopter flying at 500 feet is about 87 decibels, according to the Helicopter Association International (HAI) (official website). The sound level decreases to 78 decibels at 1,000 ft.
Excessive and distracting helicopter noise has the potential to be harmful to public health. According to the World Health Organisation, noise sensitivity causes behavioral changes and discomfort in addition to hearing loss at the extreme and a loss of attention at the least.

Helicopter Noise Mitigation

To counter the most common sources of helicopter noise, noise reduction techniques are usually used during the design process. There are, however, tactical procedures that can be used to reduce helicopter noise when in flight.
Helicopters, for instance, make more noise when turning than when going straight since the air vortices around the blades change with the change in direction. Decelerating, turning onto the moving sword, and steep descents all trigger this.
Reduce the noise of the blade-vortex interaction by reducing turns and preventing deceleration while turning. As compared to steep approaches, shallow approaches can help reduce noise.

Video: Can We Really Have Stealth Helicopters When They’re So Loud?

7. Lawn and Garden Equipment

In the United States, more than 11 million Gas Powered Leaf Blowers (GLBs) were in use. GLBs are used for a variety of activities in cities, classrooms, hospitals, and public areas, for sweeping dirt including leaf, mud, and debris, and snow removal. The majority of leaf blower operation is produced by commercial-grade machines.
The sound pressure ranges of these instruments, according to manufacturer records, reach 95 A-weighted decibels (dB[A]) at the operator’s ear and usually 65–80 dB(A) at 50 feet. As compared to the World Health Organization’s daytime sound guidelines, these amounts are up to 15 decibels (A) higher than the recommended 55 decibels.

Law Against GLBs

More than a hundred cities and towns in the United States have banned or restricted the use of gas-powered leaf blowers. For instance, Larchmont, New York, became the first town in the northeast to enact a full ban, and California, where more than 80 cities have enacted rules, is considering phasing out gas-powered garden tools entirely.

Lawn and Garden Equipment Noise Mitigation

As a homeowner, you can help to reduce noise during lawn and garden work by buying noise-friendly equipment first. In the lawn equipment industry, electric power tools are becoming more competitive. These machines are just as efficient as their gas-powered predecessors, but they are also cleaner and quieter.
Use power tools during the day when many people expect noise or are at work if you want to foster healthy relationships in your neighborhood. If at all possible, limit yourself to 15 to 20 minutes a day for your lawn equipment and power tools.

Video: How to Reduce Noise in Your Backyard | Backyardscape

8. Car Stereos

In addition to causing damage to your own ears, car stereos annoy the general population. Loud car stereos, particularly those with a lot of bass, can be heard from a long way away. Car stereos usually have a decibel limit of 75 to 80 decibels, which is measured at different distances from the vehicle.

Is It Illegal to blast Your Car Stereo Loud?

While there is no actual federal law banning the use of loud car stereos, many states and cities have laws prohibiting the use of such devices at certain decibel levels or at certain times of the day. Many lawmakers and homeowners have taken court steps to prohibit noisy engines, dubbed “boom cars” by locals. Since then, further laws have been passed that place restrictions on the volume of car stereos.

Car Stereos Noise Mitigation

At no point should you play loud music in a residential area? Particularly if you’re planning on doing more than passing by. When you drive into a neighborhood, there are just too many residents who would call the cops (more info about noisy neighbors on
The majority of non-bass sounds would be blocked out if your windows are kept open. Reduce the volume of the subwoofers while maintaining the bass in the front speakers. If you’re also not sure what the laws are in your town or the one you’re passing by, keep the windows rolled up, and don’t blast the radio after 8 p.m.

Video: BUZZ, WHINE, HISS? How to FIX Car Audio Noise!

9. Motorcycles

Motorcycles in the United States are designed to meet nationally imposed noise control requirements. Some motorcycles are noisy because the exhaust system has been modified or an aftermarket exhaust system has been installed that is not street legal.
A rumbling exhaust machine can be heard and felt from a long way out, rattling windows and penetrating walls.
Motorcycle riders who have installed noisy aftermarket exhaust systems often say that “loud pipes save lives,” implying that they are more likely to hear confused motorists on the lane. There has never been researched that shows a connection between a motorcycle exhaust system’s noise level and its potential to reduce accidents.

Motorcycle Noise Standards

Motorcycles built after 1979 are required by state law to have a noise level of 84 decibels (dB) while driving more than 35 mph on a paved street or highway. This is noisier than the highest noise thresholds permitted for automobiles but quieter than the noise levels permitted for buses and other equipment weighing more than 10,000 pounds.
According to state legislation, the DMV commissioner must follow rules that set maximum allowable noise limits for all motor vehicles, including motorcycles, with the recommendation of the Department of Environmental Protection. The statute bans someone from driving a vehicle in a condition that exceeds the vehicle’s maximum decibel level at any time or in any circumstance.

Motorcycle Noise Mitigation

The problem can be solved in two ways: education and enforcement. It’s possible that some adult bikers lack civic awareness. Thus, the appropriate authority should advise motorists about the value of maintaining peace and quiet in residential neighborhoods, as well as the psychological harm that errant motorcyclists can inflict.

Video: How to make your motorcycle quieter?

10. Piped In Music

Piped in music or background music are a disturbance and a form of noise pollution. When it comes to determining noise levels, background noise is crucial. Hospitals, schools, swimming pools, bars, stores, and restaurants all have this kind of background music. Unwanted piped music, also known as elevator music, muzak, or canned music, is any song played continuously in a space or building where people have come for reasons other than listening to it.

Pipedown (Campaign)

Nigel Rodgers (official website), a British author, and environmentalist created the Pipedown Movement for Freedom from Piped Music (official website) in 1992. Members of the movement protested the piped music played throughout Gatwick Airport, which was one of the campaign’s early victories. Gatwick Airport turned down they’re piped in music because of the noise component of the campaign and the people inside the airport.

Piped in music mitigation

Piped music must be regulated in certain decibels so that it will not affect the people hearing it or pose a nuisance. Furthermore, for the people affected, it is recommended to use any devices with the noise-canceling capability to block the nuisance. If the problem persists, the person affected must adhere to the administrator of the building where the piped-in music is being played.

11. Remote Car Honking

A standard car horn has a decibel range of 100-110, making it loud enough to be heard over various cars and sounds on the ground. The volume of a car horn is important because it needs to be heard by someone who isn’t always paying attention.
Vehicle traffic accounts for approximately 55 percent of the urban noise. Horn noise events boost the equivalent noise level from 2 to 13 decibels. As a result, certain complex considerations must be taken into account when measuring and assessing car honks, as well as when planning noise abatement steps.

Remote Car Honking Regulations

Since car horns are so important for society’s overall protection, there are many rules that must be followed when it comes to their sound, noise level, location, and use. In certain jurisdictions, honking a car horn violently or out of indignation will result in a ticket. The general rule is that honking should be avoided between the hours of 11:00 p.m. and 7:00 a.m. unless it is done properly.

Remote Car Honking Mitigation

Following up from the previous discussion of how noisy typical horns are, different locations would have different limits on how loud horns can be. This is mostly limited to a decibel level of 150 to 175 decibels and is when train horns and other loud noises are prohibited.
When it comes to the vehicle’s remote horns, the bottom line is to actually use them for their intended function and avoid making too many changes to the mechanism. They are intended to assist people to keep everybody on the road secure, and they should be used as such.

Video: Honking in Harmony

12. Sports Stadium

The sports stadium is one of the noisiest places to be. During an NFL game, the maximum volume is calculated to be in the mid-90 decibel range.
Sound levels at the race car track have been calculated up to 140 A-weighted decibels (dBA) in the pits, 96 dBA in the seats, and 114 dBA for drivers, according to the National Institute on Occupational Safety and Health (NIOSH) (official website).
Other athletic activities can be very loud as well. The noise level in the stadium during the 2012 Super Bowl increased to 107 dBA, as determined by fans using free mobile applications at NIOSH’s request.

General Precaution

Daily listening to sounds at or above 85 dBA puts you at risk for irreversible hearing loss, whereas sounds at or below 70 dBA are normally considered healthy. When sounds are 100 dBA or louder, for example, you will ruin your hearing in less than 15 minutes if you don’t wear hearing protectors, and in less than 2 minutes if sounds are 110 dBA or louder.
If you’re going to a sporting event, whether indoors or outside, think about how loud it’ll be and bring your hearing protection.

Sports Stadium Crowd Cheering – Sound Effect for editing

13. Trains Honk

On locomotives, train horns are mounted to alert motorists and pedestrians about an approaching train at a highway-rail grade crossing. Unfortunately, those who live or work along highway-rail-grade crossings may be greatly disturbed by the locomotive horn.

The Train Horn Rule

Locomotive engineers should sound train horns at least 15 seconds and no more than 20 seconds before all public grade crossings, according to the Train Horn Rule (49 CFR Part 222) (official website).
Engineers will not sound the horn until the train is within 14 miles of the crossing, even though the advance alarm is less than 15 seconds if the train is going more than 60 mph. The train horn’s full volume rating is now 110 decibels, which is a new standard. The sound frequency must be at least 96 decibels.

Quiet Zones

The final rule also gives local governments around the country the option of creating “new quiet zones” to help reduce the impact of train horn noise. “No horn” restrictions that occurred previous to the rule’s establishment could be classified as “pre-rule quiet zones.”
Railroads have been told to stop sounding their horns while approaching public highway-rail grade crossings in a quiet zone.

Video: The purpose of train horns

Flick Emil Henricus

I'm a 34-year-old freelance musician and soundproofing specialist, DIY enthusiast, blog author, and Silence Wiki founder originally from the Netherlands. I've been a musician for over 15 years now - playing all sorts of instruments but especially guitar and saxophone. As a soundproofing specialist, I help people with their acoustic needs in order to make them happy! I also enjoy DIY projects around the house or wherever else they are needed - thanks to my wife who always has great ideas!

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