noise pollution

noise pollution, human-created noise harmful to health or welfare. Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses, automobiles, and motorcycles all producing excessive noise. Construction equipment, e.g., jackhammers and bulldozers, also produce substantial noise pollution.

Noise intensity is measured in decibel units. The decibel scale is logarithmic; each 10-decibel increase represents a tenfold increase in noise intensity. Human perception of loudness also conforms to a logarithmic scale; a 10-decibel increase is perceived as roughly a doubling of loudness. Thus, 30 decibels is 10 times more intense than 20 decibels and sounds twice as loud; 40 decibels is 100 times more intense than 20 and sounds 4 times as loud; 80 decibels is 1 million times more intense than 20 and sounds 64 times as loud. Distance diminishes the effective decibel level reaching the ear. Thus, moderate auto traffic at a distance of 100 ft (30 m) rates about 50 decibels. To a driver with a car window open or a pedestrian on the sidewalk, the same traffic rates about 70 decibels; that is, it sounds 4 times louder. At a distance of 2,000 ft (600 m), the noise of a jet takeoff reaches about 110 decibels—approximately the same as an automobile horn only 3 ft (1 m) away.

Subjected to 45 decibels of noise, the average person cannot sleep. At 120 decibels the ear registers pain, but hearing damage begins at a much lower level, about 85 decibels. The duration of the exposure is also important. There is evidence that among young Americans hearing sensitivity is decreasing year by year because of exposure to noise, including excessively amplified music. Apart from hearing loss, such noise can cause lack of sleep, irritability, heartburn, indigestion, ulcers, high blood pressure, and possibly heart disease. One burst of noise, as from a passing truck, is known to alter endocrine, neurological, and cardiovascular functions in many individuals; prolonged or frequent exposure to such noise tends to make the physiological disturbances chronic. In addition, noise-induced stress creates severe tension in daily living and contributes to mental illness.

Noise is recognized as a controllable pollutant that can yield to abatement technology. In the United States the Noise Control Act of 1972 empowered the Environmental Protection Agency to determine the limits of noise required to protect public health and welfare; to set noise emission standards for major sources of noise in the environment, including transportation equipment and facilities, construction equipment, and electrical machinery; and to recommend regulations for controlling aircraft noise and sonic booms. Also in the 1970s, the Occupational Safety and Health Administration began to try to reduce workplace noise. Funding for these efforts and similar local efforts was severely cut in the early 1980s, and enforcement became negligible.

Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. The dominant form of noise pollution is from transportation sources, principally motor vehicles^[1] . The word "noise" comes from the Latin word nausea meaning "seasickness", or from a derivative (perhaps Latin noxia) of Latin noceō = "I do harm", referring originally to nuisance noise.^[2] 

The overarching source of most noise worldwide is generated by transportation systems, principally motor vehicle noise, but also including aircraft noise and rail noise.^[3][4]. Hybrid vehicles are the first innovation within the last 100 years to achieve significant widespread noise source reduction.^{[citation needed]} Poor urban planning may also give rise to noise pollution, since juxtaposition of industrial to residential land uses, for example, often results in adverse consequences for the residential acoustic environment.

Besides transportation noise, other prominent sources are office equipment, factory machinery, appliances, power tools, lighting hum and audio entertainment systems. Furthermore, with the popularity of digital audio player devices, individuals in a noisy area might increase the volume in order to drown out ambient sounds. Construction equipment also produces noise pollution.

Noise from recreational vehicles has become a serious problem in rural areas. ATVs, also known as quads, have increased in popularity and are joining the traditional two wheeled dirt motorcycles for off-road riding.

The noise from ATV machines is quite different from of the traditional dirt bike. Some ATVs have large bore, four stroke engines that produce a loud throaty growl that will carry further due to the lower frequencies involved. The traditional two stroke engines on dirt bikes have gotten larger and, while they have higher frequencies, they still can propagate the sound for a mile or more. The noise produced by these vehicles is particularly disturbing due to the wide variations in frequency and volume.

Recreational vehicles are generally not required to be registered and control of the noise they emit is absent in most communities. However, there is a growing awareness that operation of these machines can seriously degrade the quality of life of those within earshot of the noise and some communities have enacted regulations, either by imposing limits on the sound or through land use laws. Rider organizations are also beginning to recognize the problem and are enlightening members as to future restrictions on riding if noise is not curtailed. because of human beings

Human health

Principal noise health effects are both health and behavioral in nature. The following discussion refers to sound levels that are present within 30 to 150 meters from a moderately busy highway. Sound is a particular auditory impression perceived by the sense of hearing. The presence of unwanted sound is a called noise pollution. This unwanted sound can seriously damage and effect physiological and psychological health. For instance, noise pollution can cause annoyance and aggression, hypertension, high stress levels, tinnitus, hearing loss, and other harmful effects depending on the level of sound, or how loud it is.^[5][6] Furthermore, stress and hypertension are the leading causes to health problems, whereas tinnitus can lead to forgetfulness, severe depression and at times panic attacks.^[7][8]

Hearing

The mechanism for chronic exposure to noise leading to hearing loss is well established. The elevated sound levels cause trauma to the cochlear structure in the inner ear, which gives rise to irreversible hearing loss.^[5]

The outer ear (visible portion of the human ear) combined with the middle ear amplifies sound levels by a factor of 20 when sound reaches the inner ear.^[9]

In Rosen's seminal work on serious health effects regarding hearing loss and coronary artery disease, one of his findings derived from tracking Maaban tribesmen, who were insignificantly exposed to transportation or industrial noise. This population was systematically compared by cohort group to a typical U.S. population. The findings proved that aging is an almost insignificant cause of hearing loss, which instead is associated with chronic exposure to moderately high levels of environmental noise.^[5]

Cardiovascular health

High noise levels can contribute to cardiovascular effects and exposure to moderately high (e.g. above 70 dBA) levels during a single eight hour period causes a statistical rise in blood pressure of five to ten mmHg; a clear and measurable increase in stress ^[10]; and vasoconstriction leading to the increased blood pressure noted above as well as to increased incidence of coronary artery disease.

Annoyance

Though it pales in comparison to the health effects noted above, noise pollution constitutes a significant factor of annoyance and distraction in modern artificial environments:

1.                  The meaning listeners attribute to the sound influences annoyance, so that, if listeners dislike the noise content, they are annoyed. What is music to one is noise to another.

2.                  If the sound causes activity interference, noise is more likely to annoy (for example, sleep disturbance)

3.                  If listeners feel they can control the noise source, the less likely the noise will be annoying.

4.                  If listeners believe that the noise is subject to third-party control, including police, but control has failed, they are more annoyed.

5.                  The inherent unpleasantness of the sound causes annoyance.

6.                  Contextual sound. If the sound is appropriate for the activity it is in context. If one is at a race track the noise is in context and the psychological effects are absent. If one is at an outdoor picnic the race track noise will produce adverse psychological and physical effects.

A 2005 study by Spanish researchers found that in urban areas households are willing to pay approximately four Euros per decibel per year for noise reduction^[11].

Environment

Noise pollution can also be harmful to wildlife . High noise levels may interfere with the natural cycles of animals, including feeding behavior, breeding rituals and migration paths.^{[citation needed]} The most significant impact of noise to animal life is the systematic reduction of usable habitat, which in the case of endangered species may be an important part of the path to extinction. Perhaps the most sensational damage caused by noise pollution is the death of certain species of beached whales, brought on by the extremely loud (up to 200 decibels) sound of military sonar.^{[citation needed]}

Mitigation and control of noise

The sound tube in Melbourne, Australia, designed to reduce roadway noise without detracting from the area's aesthetics.

There is also technology that has been applied with the aim of mitigating or containing noise as much as possible, provided that it has a sufficiently localized source.

·                     Roadway noise, is the most widespread environmental component of noise pollution worldwide. There are a variety of effective strategies for mitigating adverse sound levels including: use of noise barriers, limitation of vehicle speeds, alteration of roadway surface texture, limitation of heavy duty vehicles, use of traffic controls that smooth vehicle flow to reduce braking and acceleration, innovative tire design and other methods. Thousands of case studies in the U.S. alone have been documented starting in 1970, indicating substantial improvement in roadway planning and design. The most important factor in applying these strategies is a computer model for roadway noise, that is capable of addressing local topography, meteorology, traffic operations and hypothetical mitigation. Costs of building in mitigation is often quite modest, provided these solutions are sought in the planning stage of a roadway project.

·                     Aircraft noise can be reduced to some extent by design of quieter jet engines, which was pursued vigorously in the 1970s and 1980s. This strategy has brought limited but noticeable reduction of urban sound levels. Reconsideration of operations, such as altering flight paths and time of day runway use, have demonstrated significant benefits for residential populations near airports. FAA sponsored residential retrofit (insulation) programs initiated in the 1970s has also enjoyed widespread success in reducing interior residential noise in thousands of affected residences across the United States.

·                     Exposure of Industrial noise on workers has the longest history of scientific study, having been addressed since the 1930s. This scientific studies have emphasized redesign of industrial equipment, shock mounting assemblies and physical barriers in the workplace. Innovations have had considerable success; however, the costs of retrofitting existing systems is often rather high.

Legal status

Governments up until the 1970s viewed noise as a "nuisance" rather than an environmental problem. In the United States there are federal standards for highway and aircraft noise; states and local governments typically have very specific statutes on building codes, urban planning and roadway development. In Canada and the EU there are few national, provincial, or state laws that protect against noise. As a result in Canada and the EU, most regulation has been left up to municipal authorities.

Noise laws and ordinances vary widely among municipalities and indeed do not even exist in some cities. An ordinance may contain a general prohibition against making noise that is a nuisance, or it may set out specific guidelines for the level of noise allowable at certain times of the day and for certain activities. Exceptions are generally made for activities considered essential public services such as refuse collection and emergency vehicles.

Most city ordinances prohibit sound above a threshold intensity from trespassing over property line at night, typically between 10 p.m. and 6 a.m., and during the day restricts it to a higher decibel 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. For persistent nuisances, individuals may have to seek damages through the civil courts. Many jurisdictions, such as New York City and Chicago authorize police to impound cars with loud stereos and to hold the cars as evidence until the citation has been adjudicated.

Many conflicts over noise pollution are handled by negotiation between the emitter and the receiver. Escalation procedures vary by country, and may include action in conjunction with local authorities, in particular the police. Clear documentation, repetitive complaints, getting neighbors involved, and forming a Neighborhood Watch can be effective at obtaining enforcement. Noise pollution often persists because only five to ten percent of people affected by noise will lodge a formal complaint^{[citation needed]}. Many people are not aware of their legal right to quiet and do not know how to register a complaint. Furthermore, mobile noise sources are transitory such that they may be difficult to pursue unless a noise measurement device is in place, so effectiveness tends to depend on whether a city has instituted proactive enforcement policies (e.g. muffler inspections).

What is Noise Pollution?

Noise pollution is not easily defined because it is different from other forms of pollution. One measure of pollution is the danger it poses to health. Noise causes stress, which is a leading cause of illness and suicide. Therefore, any form of noise can be considered pollution if it causes annoyance, sleeplessness, fright, or any other stress reaction.

• Noise is transient; once the pollution stops, the environment is free of it. This is not the case for chemicals, sewage, and other pollutants introduced into the air, soil, or water.
• Other forms of pollution can be measured, and scientists can estimate how much material can be introduced into the environment before harm is done. We can measure individual sounds that may damage human hearing, but it is difficult to monitor cumulative exposure to noise or to determine just how much is too much.
• The definition of noise itself is highly subjective. To some people the roar of an engine is satisfying or thrilling; to others it is an annoyance. Loud music may be enjoyable or a torment, depending on the listener and the circumstances.
   

Broadly speaking, any form of unwelcome sound is noise pollution, whether it is the roar of a jet plane overhead or the sound of a barking dog a block away. The actual loudness of a sound is only one component of the effect it has on human beings. Other factors to consider are the time and place, the duration, the source of the sound, and whether the listener has any control over it. Most people would not be bothered by the sound of a 21-gun salute on a special occasion. On the other hand, the thump-thump of a neighbour's music at 2 a.m., even if barely audible, could be a major source of stress.

Measuring Sound by Decibel (dB)

The decibel (dB) is a measure of sound intensity; that is, the magnitude of the fluctuations in air pressure caused by sound waves. The decibel scale is logarithmic, not arithmetic. This means that a doubling of sound intensity is not represented as a doubling of the decibel level. In fact, an increase of just 3 dB means twice as much sound, and an increase of 10 dB means ten times as much sound.

A sound pressure level of 0 dB represents the threshold of hearing in the most sensitive frequency range of a young, healthy ear, while the thresholds of tickling or painful sensations in the ear occur at about 120 to 130 dB.

Decibels are usually measured with a filter that emphasizes sounds in certain frequencies. The "A" filter (dBA) is the one most frequently used. The "C" filter (dBC) puts more weight on low-frequency sounds such as the bass in amplified music.

The perception of loudness by the human ear is not directly proportional to the decibel level. For example, a sound 10 dB greater than another is not perceived as being ten times as loud but only about three times as loud.

The intensity of noise diminishes with distance. Outdoors, and in absence of any close reflecting surface, the effective decibel level diminishes at a rate of 6 dB for each factor of two increase in distance. For example, a sound measuring 100 dB at 10 metres would be 94 dB at 20 metres, 88 dB at 40 metres, and so on.

How loud does noise have to be before it's dangerous?

Because permanent hearing loss is usually a long-term process, it is impossible to know at exactly what point noise becomes loud enough to cause damage to the ears.

The U.S. Environmental Protection Agency has established 70 dBA as a safe average for a 24-hour day. (This figure is based only on the risk to hearing, and does not take into account other health factors such as loss of sleep.)

Since sound intensity doubles with every increase of 3 dB, the time of safe exposure would be cut in half with each such increase. Thus a worker should wear ear protection if exposed to a steady 75 dBA for eight hours, 78 dBA for four hours, and so on. Brief exposure to noises of up to 100 dBA is not considered risky, provided the average remains within the prescribed levels.

Actual limits for labour tend to be more permissive. In most jurisdictions, workers are permitted to be exposed to up to 85 or even 90 dBA for eight hours. Using the higher of these figures, the sound level in a typical nightclub, 110 dBA, could pose a risk of permanent hearing damage after as little as four minutes of exposure.

Of course, noise is dangerous in other ways too. It can be a cause of stress, illness, suicide, aggression, and violence. As stated above, the volume of noise is only one component of its effect.
For a more technical explanation, click here.

Does the law protect me against noise?

In Canada and the United States there are no national, provincial, or state laws that give blanket protection against noise, though there are some specific regulations governing manufacturing standards, air traffic, vehicle mufflers, and so on. Criminal laws may also cover things like noisy parties.

Governments have traditionally viewed noise as a nuisance rather than an environmental problem. As a result, most regulation has been left up to municipal authorities.

Noise bylaws and ordinances vary widely from one municipality to another and do not even exist in some towns and cities. Where they exist, they may contain a general prohibition against making noise that is a nuisance to other people, or they may set out specific guidelines for the level of noise allowable at certain times of the day and for certain activities. Exceptions are generally made for activities considered legitimate or necessary, such as lawn mowing or garbage collection.

Regardless of how lax or stringent a local law may be, enforcement is difficult. Many municipalities do not have adequate resources to follow-up on complaints. Even where a municipality has an enforcement office, it may be unwilling to do more than issue warnings, since taking offenders to court is expensive. The police may also act on certain kinds of noise complaints, but generally do not assign them a high priority.
For persistent nuisances, the individual may have to seek damages through the civil courts. This can be a long, costly procedure with no certainty of success.

In short, legal protection against noise is very patchy and often inadequate.

Is there evidence that noise can make us sick?

Yes, though much of it is buried in scholarly journals. We know of only one book in print: Noise & Health, edited by Thomas H. Fay, published by The New York Academy of Medicine (1991). This book presents a critical and comprehensive review of available world literature on the effects of noise on all of the body's systems. It defines noise and its sources, documents the specific health hazards of noise on the body, and indicates needs for further research.
 

Cick here to visit Resources for more information

No one on earth can escape the sounds of noise- an unwanted, disturbing sound that causes a nuisance in the eye of the beholder. Noise is a disturbance to the human environment that is escalating at such a high rate that it will become a major threat to the quality of human lives. In the past thirty years, noise in all areas, especially in urban areas, have been increasing rapidly. There are numerous effects on the human environment due to the increase in noise pollution. In the following paper, the cause and effects of noise pollution will be presented in some detail. Slowly, insensibly, we seem to accept noise and the physiological and psychological deterioration that accompanies it as an inevitable part of our lives. Although we attempt to set standards for some of the most major sources of noise, we often are unable to monitor them. Major sources of noise can be airplanes at takeoff and landing, and a truck just off the assembly line, yet we seem accept and enjoy countless other sounds, from hard rock music to loud Harley Davidson motor cycles. The following areas will be investigated in some detail; adolescent education, neural-effects, sleep, hearing damage, occupational environment, transportation, and physiological effects.

Almost everyone has had one experience of being temporarily "deafened" by a loud noise. This "deafness" in not permanent, although it is often accompanied by a ringing in the ears, and one can hear another person if he raises his voice. Likewise, normal hearing comes back within a few hours at most. This sort of partial hearing loss is called Temporary Threshold Shift (TTS) (Bugliarello, et al., 1976). A TTS may be experienced after firing a gun or after a long drive in the car with the windows open. It may not be considered that if exposure to this type of loud noise at a rate of eight hours a day, five days a week can is a threat to develop permanent hearing loss. This type of exposure to noise does not have to be as loud as a gun being fired; it can be as simple as a person shouting across the room. The type of hearing loss is any degree from partial to complete hearing loss. This loss, usually, is permanent and is not satisfactorily corrected by any devices such as, hearing aids. The loss is caused by the destruction of the delicate hair cells and their auditory nerve connections in the Organ of Corti, which is contained in the cochlea (Bugliarello, et al., 1976). Every exposure to loud noise destroys some cells, but prolonged exposure damages a larger amount of cells, and ultimately collapses the Organ of Corti, which causes deafness.

Most of society is now aware that noise can damage hearing. However, short of a threat that disaster would overtake the human race if nothing is done about noise, it is unlikely that many people today would become strongly motivated to do something about the problem. Yet, the evidence about the ill effects of noise does not allow for complacency or neglect. For instance, researchers working with children with hearing disorders are constantly reminded of the crucial importance of hearing to children. In the early years the child cannot learn to speak without special training if he has enough hearing loss to interfere effectively with the hearing of words in context (Bugliarello, et al., 1976). In this respect, there is a clear need for parents to protect their children?s hearing as they try to protect their eyesight. If no steps are taken to lessen the effects of noise, we may expect a significant percentage of future generations to have hearing damage. It would be difficult to predict the total outcome if total population would suffer hearing loss. Conceivably, the loss could even be detrimental to our survival if it were ever necessary for us to be able to hear high frequencies. Colavita has consistently been unable to find among university students in his classes any who could hear 20 kHz, although the classical results of Fletcher and Munson show 20 kHz as an audible frequency (Fletcher, 1953).

There are two types of hearing loss: conductive and sensorineural (see fig.1 for anatomy of the ear). In conductive deafness sound-pressure waves never reach the cochlea, most often as a consequence of a ruptured eardrum or a defect in the ossicles of the middle ear (Bugliarello, et al., 1976).

The three bones form a system of levers linked together, hammer pushing anvil, anvil-pushing stirrup. Working together, the bones amplify the force of sound vibrations. Taken together, the bones double, often treble the force of the vibrations reaching the eardrum (Bugliarello, et al., 1976).

Mitigation of potentially harmful amplification occurs via muscles of the middle ear. These muscles act as safety device protection the ear against excessive vibrations from very loud noises, very much like an automatic damper or volume control.

When jarring sounds with their rapid vibrations strike the eardrum; the muscles twist the bones slightly, allowing the stirrup to rotate in a different direction. With this directional shift, less force is transmitted to the inner ear: less, not all (Bugliarello, et al., 1976).

The human ear is a delicate and fragile anatomical structure on the other hand it?s a fairly powerful physical force. These muscles act quickly but not always as in examples of when the ear catches the sound of gun being shot unexpectedly. The muscles of the ear were relaxed and were unprepared for such a blast, because of this damage was done.

Conductive hearing loss can be minimized, even overcome by use of the familiar hearing aids. The most common is worn over the mastoid bond behind the pinna. It picks up sound waves and transmits them through the skull to the cochlea.

Sensorineural hearing loss, the most common form in the United States, occurs as a result of advancing age as well as exposure to loud noises. In both instances there is a disruption of the organ of Corti. The organ serves two functions: converting mechanical energy to electrical and dispatching to the brain a coded version of the original sound with information bout frequency, intensity, and timbre. The hair cells of the organ of Corti send their electrochemical signals into the central nervous system, where the signals are picked up by thousands of auditory nerve fibers and transmitted to the brain. It is the decoding of all the information that enables a person to distinguish the unique ant separate sounds of a violin, trumpet, and clarinet, even all three are playing the same note.

The organ of corti, a gelatinous mass, is on of the best protected parts of the body, encased as it is within the cochlea which in turn is deeply embedded in the temporal bone, perhaps the hardest of the 206 bones (Bugliarello, et al., 1976). None the less, loud noise can damage the hair cells and the auditory nerve, producing at times, depending on the type of noise, sudden and often total deafness.

Sustained noise over a period of time can also engender sensorineural deafness in the form of gradual losses in hearing. This is the most common loss in teenagers today listening to loud rock music (Bugliarello, et al., 1976).

Until a few years ago, sensorineural deafness could not be helped by hearing aids. However, with advances in electronic wizardry and miniaturization, devices for insertion into the auditory canal are available.

The question is now; how much noise communities will tolerate or at what point the citizenry will have reached its threshold has never had greater currency. The number of towns enacting strict and enforceable ordinances to reduce and control noise levels, both day and night suggests the point have been reached.

Barking dogs, lawn mowers, leaf blowers, power saws, snow blowers, church bells, jackhammers, motorcycles, airplanes, car stereo systems, and traffic generally have combined to such a degree that noise induced irritation, annoyance, discomfort, and hearing impairment have become a significant public health issue, certainly enough of one to motivate a political response.

Tables 1 and 2 indicate the magnitude of the U.S. population exposed to noise, and the percentage expressing annoyance with specific sources of noise. Considering that 60-dB is akin to the sound of an air conditioner at a distance of 20ft, it is evident that with a population in excess of 280 million approximately 7%, or 17+ million people are exposed to noise levels, from traffic alone, of from 70 to over 80 dB (U.S. EPA).

Results and Discussion

Hearing loss can be entrapping in onset. Years of traumatic exposure to high levels can occur before symptoms become manifest. The popularity for portable sound equipment such as Walkman-type radios and tape players has already has already produced a sharp increase in clinically verified hearing loss, especially among rock music addicts who prefer their music very loud (Benarde, 1989).

Obviously, the Walkman-radio industry believes it is not their products that are the problem; rather it is improper use. If, they say, the volume is kept down, there would be no problem, which is equivalent to saying that if we all drove cautiously there would be no accidents.

Considering that earphone listening has been around for some 20 years, why has the problem only recently surfaced? Apparently the pattern of listening has changed. Currently, earphones are used while walking or running on noisy easy streets rather than in the privacy of the home or other relatively quiet area where the listener did not wish to disturb others. Now the volume must be turned up to overcome the noise of city traffic. The listener wants the Walkman to blot out the "noises of the city." Doing those courts hearing disaster. A similar result occurs to users in noisy factory or industrial environments.

Since to these people, louder is better, the makings for an epidemic of hearing loss are at hand.

The Occupational Safety and Health Agency (OSHA) has set the danger level at 95 decibels (dB) and above for 4 or more hours per day as likely to induce permanent hearing impairment (Benarde, 1989).

Related to the Walkman study, a recent study conducted in New York City by Jane Mandell. Her data showed that much of the ambulatory music is played at levels well beyond the 95-dB?upward of 100 and 125- close to the sound level of jackhammers it may be that OSHA?s 95-dB is far to lenient and the damage occurs below 90-dB.

Another example was during the spring and summer of 1983; Sweden?s security was sorely tried. Russian submarines tried to penetrate restricted naval installations in the Hors Bay area along Sweden?s northeast coast. According to initial reports by officials of the Naval Ministry, underwater sound-detecting gear functioned poorly making it difficult to pinpoint the location of the subs.

It was later determined that the problem lay elsewhere. The young Swedish sailors manning the monitors had in fact developed hearing losses as a consequence of excessive exposure to rock music. On learning this, other governments moved quickly to ascertain the hearing acuity of detectors. Consequently, the problem of exposure to sound levels detrimental to hearing takes on new and more serious dimensions (Benarde, 1989).

Yet it has been argued that because noise produces no dramatic ill effects, the public has been largely uninterested in its suppression. It may be more to the point to say that the degree of annoyance and discomfort that people will endure is astonishing.

Although noise is an integral part of civilization, it would appear that unless some definite steps are taken to reduce the present inordinate levels in both industry and community generally, more people will become auditory cripples.

Fortunately, in the past few years? large portions of the population have expressed an increasing determination to revolt against noise. A measure of this is seen in the number of communities moving forcefully to reduce noise levels in their home areas.

Vexation and anger with increasing noisy communities is not a uniquely American problem. Between May and July 1984, over 70% of the adult population of Yamato, Japan, signed petitions demanding cessation of the U.S. Navy?s flight activities over their city, Yamato, with a population of 175,000, is a bedroom community for Tokyo, some 20 miles to the northeast. U.S. Navy fighter aircraft, F-4, A-6, and E-2 jets, 100 of them on station aboard the aircraft carrier U.S.S. Midway, fly over Yamato as they come in for landings at nearby Atsugi Air Base. As the jets sweep low they rattle houses and residents. The evenings are the worst with more takeoffs and landings at full power and thus maximum noise, at a time, of curse when the people are trying to sleep (Benarde, 1989).

Kenichi Ohsakas, a Yamato City official who keeps track of noise levels, has been reported as saying, "it?s just like living inside a subway car." Yamato holds regular weekly takeoff and landing exercises to keep its pilot?s skills honed, and night sessions are particularly important. Be that as it may, the residents are unimpressed, cannot sleep, and prefer the training sessions to be moved elsewhere. But where else? No one wants them and there wretched noise.

Airplane noise can be a much greater disturbance to sleep than other noises. Research indicates that near a major airport-London (Heathrow) Airport- the number of people awakened by airplanes is about 50% greater than the number awakened by other noises (Holland-Wegman, 1967). If we don?t isolate the problem it is going to overtake the country.

Aircraft noise began to be a major problem with the great surge in air transportation that followed World War II. The introduction of jet airplanes, which came into widespread use by the end of the 1950?(Bugliarello, et al., 1976) led to a second revolution in aviation, as well as to an escalation of the noise level from aircraft?s. Since then, annoyance to people living near airports caused by the noise of jet takeoffs and landings has become a psychophysiological and economic problem of enormous magnitude and complexity. Still a third escalation in aircraft noise will occur when supersonic transports come into commercial operation, and if general aviation and, above all, vertical take off and landing.

As a result of the diffusion of air traffic, airports tend to occupy very large land areas with multiple runways, and large airspace?s involved in landing and takeoff procedures. At the same time, under the pressure of population, communities tend to expand toward airports and thus to enter into zones of higher noise. For instance, in the area around London (Heathrow) Airport, the population has increased by 30% since 1963 (Wilson, 1983). Also, an increasing number of people are working in airports and in other areas of the aviation industry. There are signs that people?s tolerance to airport noise is decreasing, particularly as socio-economic status improves.

In the United States airport noise has been hit the hardest, than any other developed country due to the large geographic area. In 1966, in the United States there were 500 commercial air passengers per 1000 inhabitants, versus 106 for the United Kingdom, 85 for West Germany, and 36 for France (Alexandre, 1970). By the end 1971, U.S. scheduled airlines carried nearly 80% of all U.S. inter-city passengers traffic traveling by common carrier (NIPCC, 1970); the major portion of the fleet of passenger and cargo planes was powered by jet engines, and accounted for the near totality of the capacity flown.

Studies of both traffic noise and noise in communities hard by major airports have concluded that elevated blood pressure, heart disease, and psychological trauma are direct consequences of noise exposure. Although these associations have been reported, others contradict or do not bear them out. Hypertension, heart disease and psychological trauma, as well as irritation and annoyance can be engendered by a variety of risk factors or by several operating simultaneously. Accordingly, establishing direct causal relationships can be exceedingly difficult. If research studies are methodologically deficient, complications arise to further confound relationships between the independent variable noise, and such dependent variables as elevated blood pressure, reading impairing, annoyance, anxiety, accidents, and heart disease. Obviously, with the number and variety of factors known to contribute to these events, there is good reason for contradictory results.

One example of psychological trauma is the research of Jenkins and his group at the London Institute of Psychiatry (Jenkins et al., 1979). It was reviewed the findings of two studies conducted in the area of London is Heathrow Airport. These studies had compared rates of admission at Springfield Psychiatric Hospital among residents living near Heathrow. Findings suggested that areas closest to the airport, with presumably higher levels of noise, also had the highest rates of hospital admission.

Aircraft noise is not simply a problem for those trying to sleep. Well- designed, well-controlled studies have demonstrated that exposure to high levels of aircraft and environmental noise can adversely affect reading ability in school-age children. One example is Maser and coworkers (Maser, et al 1978) reported that children who attended school beneath the Seattle-Tacoma airport lnflight paths showed a deficit on standardized tests of scholastic achievement compared to students in quiet schools.

The problem of aircraft noise is complicated by the great economic significance that the aviation industry holds to the economies of developed countries. For instance, at the end of 1971 the U.S. scheduled airlines alone had revenues of close to $10 billion, and employed almost 300,000 employees. Without airlines, a number of economic activities of great importance to notional economies from business and tourism, to the transportation of mail, would be severely affected.

Sleep disturbances are probably the most widespread source of annoyance caused by noise, if anecdotal responses are any criteria. Recently, French investigators (Vallet, 1979) studied the problem under real-life conditions in bedrooms of people living close to freeways and airports. Using miniaturized electronic units; they recorded EEG, eye movements, muscular activity, and heart rhythm with remote-reading equipment. Noise inside the rooms was recorded continuously. With the noise from the highways, subjects took longer to fall asleep and had less deep sleep so that the young to middle-aged group became more like the 50-60-year old group in their depth of sleep. Rapid eye movement (REM) sleep was also reduced. If both deep and REM sleep are physiologically and psychologically important, this type of alteration may well be damaging. But this remains to be substantiated by further study.

According to the investigations of Cohen and colleagues (Cohen, et al., 1981), reading and math scores of third grade students in noise abated classrooms were higher than those in classrooms were without that quality were.

More recently, Green and co-workers (Green et al., 1982) of New York University?s Institute of Environmental Medicine found that for all elementary schools in get boroughs of Brooklyn and Queens "an additional 3.6% of the student in the noisiest schools read at least one year below grade level". They went on to remark that "the dose response relationship indicated that the percent reading below grade level increased as noise level increased."

Other researchers have found the same kind of relationship. For example Cohen and colleagues (Cohen et al., 1973) determined that elementary school students living for at least 4 years in the lower floors of an apartment complex near heavy traffic show greater impairment of reading ability than children living on higher floors away from the traffic. In the studies, indoors sound levels varied form 66-dB on the lower floors of an apartment to 55-dB on the higher floors. In a recent U.S. EPA classification, "noisy residential areas" averaged 58-dB and were rated low socioeconomic, while "quiet residential" averaged 38-dB and were rated affluent neighborhoods. These, of course, were outdoors sound levels. With indoor levels of 55-66-dB, concentration, the ability to pay attention, may well be difficult to nonexistent. If that is true, it may be pertinent to ask why far more children are not reading impaired.

Recently Peterson and co-workers (Peterson et al., 1981) of the Department of Otolaryngology, University of Miami School of Medicine, appeared to demonstrate in rhesus monkeys that moderate levels of realistic noise can produce sustained elevations in blood pressure without significant alterations in the auditory mechanism. The unique aspect of this investigation was the finding that changes in auditory sensitivity did not necessarily follow changes in such physiological paramentes as blood pressure.

Given the concern over noise, one wonders just how desirable a quiet town would be. Darlington, near Newcastle, England, was almost such a place. Between 1976-1978, Darlington was designated a "quiet town experiment" (Gloag, 1980). Noise abatement zones and better traffic management was instituted, as were vehicle noise testing and stricter enforcement of noise regulations.

Sudden and unexpected noise has been observed to produce marked changes in the body, such as increased blood pressure, increased heart rate, and muscular contractions. Moreover, digestion, stomach contractions, and the flow of saliva and gastric juices all stop. Because the changes are so marked, repeated exposure to unexpected noise should obviously be kept to a minimum. These changes fortunately wear off as a person becomes accustomed to the noise (Broadbent, 1957). However, even when a person is accustomed to an environment where the noise level is high, physiological changes occur.

Noise has psychological effects is undoubted. The question is how these effects can be assessed and whether they lead to damage. No clear case has been made thus far for psychological damage caused by moderately high levels of noise, the levels that would cause hearing damage to only a small fraction of the people exposed. Indeed, fears have been expressed that ". . . over emphasis on damage may backfire when people come to realize that the truth of the matter seems to be simply that people can express violently their dislike about being disturbed by noises. This is recounted vividly by Connell (1972):

Future Aspects

In this paper, it has been discussed of the important aspects of a complex socio-technological problem, noise pollution. It now remains to elaborate upon some of the deeper issues that we have broached. There is no doubt that the problem of noise is serious. Large segments of the population and industrialized society are exposed to high levels of noise, not only at their place of work, but also in their residences and in their leisure activities. In the United Kingdom, for example, more than 10 percent of the population is disturbed the noise at a single airport, London Heathrow (Wilson, 1983).

Even with the relatively ambitious steps currently being taken or envisioned to control noise in most countries, sound levels and exposure to noise will remain high, and possibly increase. At the same time rising living standards will bring about demands for better environmental quality and probably lead to more vigorous and more organized protests against noise. These protest may even be triggered by lower noise levels than in the past, for it is highly likely that as the public acquires more amenities it will want to be exposed to "comfortable" rather than merely tolerable levels of sound (Bauer, 1970).

According to a WHO report to the UN Conference on Environment. Of all environmental problems, noise is the easiest to control". But the question of control will arise only after these in awareness among the people of the need for control and for the government to find some solution for it.

1. The first approach has been to reduce noise at source. Design and fabrication of silencing devices and their use in aircraft engines, trucks, cars, motorcycles, industrial machines and home appliances would be an effective measure. Protection to workers can be provided through wearing devices such as earplugs and earmuffs.
2. Making a change in design and operation of machines, vibration control, sound proof cabins and sound-absorbing materials can reduce it.
3. It can get reduced by prescribing noise limits for vehicular traffic, ban on honking of horns in certain areas and planning main traffic arteries, industrial establishments, amusement areas, residential colonies, creation of silent zones near schools and hospitals and resigning of building to make them noise proof. Other measures can involve reduction of traffic density in residential areas giving preferences to mass public transport system.
4. Control of Indoor Noise. Where outdoor noise levels have been high, the following methods can be applied for reducing their effect.

1. Locate in the building as far as possible from noise source. The noise level

   drops about 6dB each time the distance is doubled.

2. Trees and shrubs may be planted in front of building to provide some

   absorption for the sound.

3. Locate non-critical areas such as corridors kitchens, bathrooms, elevators

   and service spaces in the noisy side and critical areas each as bedrooms and

   living spaces on the quiet side.

4. Back to back bathrooms or toilets should be avoided unless they are effectively sound isolated. Bathrooms, kitchen and laundry rooms should not be adjacent to the floor.
5. Bathroom walls, floor and ceiling should be sound insulated using construction of high sound insulation glasses.
6. Noisy toilets, is bettered by quiet siphon jet type flush toilets should be installed to reduce the noise from the source. Commode seats with double siphon system are now available and may be adopted wherever possible.

1. Road Noise. Vegetation buffer zones must be created in different parts of the city. Efforts should be made for roadside plantations.
2. An Urgent Need for Legislation to Control Noise Pollution. We have seen that in India, in absences of a specific legislation for control and prevention of the noise pollution, one has to seek provisions in various branches of law and regulations. There has been no doubt that the available provisions in various branches of law and regulations. There has been no doubt that the available provisions in various branches of law are adequate, unscientific and crude. In most of the developed countries specific legislations have been made and scientific methods for investigation of noise pollution have been invented. The science of audiometer and other branched related to sound have been developed and it becomes comfortable to device various legal provisions to control and prevent noise pollution.

   As present, there is no specific and detailed legislation to control the noise

   pollution. However, there is an urgent need that the Central Government of India should manage to get a legislation passed for the control of noise pollution. Some legislation regarding water and air pollution have been made in India.

   Government should pass the ?Noise Pollution control Act? to meet special India condition. Apart from such kind of Central legislation, there should be a city noise control code for all major cities in India. Creation of unnecessary noise has to be prohibited and should be punishable under law.

3. Education. People can be educated through radio, TV, newsreels in cinema halls about noise pollution. In the family, elders can teach children to keep the radio volume low, low voice talking not to horn unnecessarily on the roads, avoid quarreling amongst each other and so on. There should be complete ban of loudspeakers form 8 p.m. to 7 a.m.
4. Public Awakening and the Control. It is also important that public awakening is also very essential for the control and prevention of the noise pollution. In India, most of the persons lack any idea about the ways in which noise pollution could be controlled. Very few scientist are aware of the problem and its control. Masses are still ignorant of the grave effects of the noise pollution. In this regard television, radio, internet, and newspapers should give a campaign for wide publicity.

Alexandre, A., 1970. Pervison de la gene due au bruit autour des aeroports et perspectives sur les moyens d?y reedier. Laboratoire d?Anthropologie Appliquee, Faculte de Medecine, Paris,

Bauer, R. A. Predicting the Future. Transportation noise---a symposium on acceptability criteria, Washington, D.C., 1970

Broadbent, D. E. 1967. Personal communication

Broadbent, D. 1957. Noise in Relation to Annoyance, Performance and Mental Health. J. Acoust. Soc. Am. Vol. 68(1): 15-17

Bugliarello, G. The Impact of Noise Pollution, New York, 1976

Cohen, A. 1969. Effects of noise on psychological state. In W. Ward and J. Fricke, Noise as a public health hazard. Washington: American Speech Hearing Association

Cohen S.; Glass, D. C.; and Singer 1973. Apartment Noise, Auditory Discrimination and Reading Ability in Children. J. Exp. Soc. Psycho. Vol. 9: 407-422.

Connell, J. 1972. The biological effects of noise. Paper given at the Annual Meeting of the British Association for the Advancement of Science.

Fletcher, H. 1972. Speech and Hearing in Communication. Princeton, NJ: Van Nostrand, 1953. Noise Control Center, Wymondkam, Leicestershire, U.K. Personal communication.

Gloag, D. 1980. Noise and Health: Public and Private Responsibility. Br. Med. J. Vol. 281: 1404-1406

Green; Pasternack; and Shore. 1982. Effects of Aircraft Noise on Reading Ability of School aged Children. Arch. Environ. Health Vol. 37: (1) 24-31.

Holland-Wegman Productions. 1967. Inc. Public Relatins for Buffalo Airport. Personal communication,

Jenkins, L. M.; Tarnapolsky, A.; Hand, D. J.; and Baker, S. M. 1979. Comparison of Three Studies of Aircraft Noise and Psychiatric Hospital Admissions Conducted in the Same Area. Psychol. Med Vol. 9: 681-693.

Maser, A.; Sorensen,; and Krypter, K. 1978. Effects of Intrusive Sound on Classroom Behavior: Data from a Successful Lawsuit. San Francisco.

Peterson, W. H. and Northwood, T. D. 1981. Noise raised blood pressure without impairing auditory sensitivity. Science Vol. 211: 1450-1452.

 United States National Industrial Pollution Control Council (NIPCC), 1970

 Vallet, M. Psychophysiological 1979. Effects of Exposure to Aircraft or to Traffic Noise. Proc. Inst. Acoustics Vol. 3: 1-4.

Von Bekesy, George. 1957. The Ear, Scientific American, 197: 61-67

Council on Environmental Quality. 1979. US Government Printing Office, Washington D.C.

US Environmental Protection Agency. 1980. The Extent of the Noise Problem.

 WHO Report. 1990. UN Conference.

The ArtUSA Noise Control Products Team is committed to enhancing the living and working environment by reducing human exposure to the harmful effects of noise, mist, dust, and smoke.

It is our goal to be an effective, responsible, and profitable company by meeting and or exceeding our customers expectations with timely, quality, cost effective solutions.

Our team is a family of customers, vendors, partners, and employees.

We offer the absolute best in Noise Control, Sound Enclosures, Acoustical Foam, Fabric Covered Acoustical Panels, Noise Control Foam,  Soundproofing, Sound Foam, Acoustical Materials, Air Quality Products and In-plant Offices.

We make the working world a quieter place. Noise Control, Soundproofing, and Sound Quality Solutions are our Mission

Noise Control Enclosures

Our enclosure systems are functional and cost effective. They are made of rugged modular components. We manufacture, package, sell, and install - Noise Control Enclosures, Industrial Enclosures, Sound Enclosures, Equipment Enclosures, Grinder Enclosures, Acoustical Enclosures, Personnel Enclosure, Barrier Walls,Thermal Enclosures, Audiometric Testing Rooms, Punch Press Enclosures, Engine Test Cells, Clean Rooms, Diesel Generator Enclosures, Positive Displacement Enclosures, Fiberglass Enclosures - In-plant Space enclosures and Offices

Noise Control Curtains and Sound Blankets

Curtain system models are offered in various styles for optimum solution of application’s
requirements. They are a flexible alternative to rigid acoustical panel systems and have a high actual noise reduction up to 25 dBA. They are durable constructions for long service life insevere industrial conditions and are custom engineered  systems with removable roof panels and ventilation systems when required that a allow quick access to machinery and equipment for operation and maintenance. They are fire safe and have low smoke emissions per ASTM E-84,Class 1: Per ASTM E-162, ASTM E-662  and easily installed, relocated or modified. They are made of washable and steam cleanable component
materials. Sound Seal.

Noise Control Foam - Sound Absorbing Foam and Noise Barriers

Art-Composite is a noise control material specifically designed to achieve maximum attenuation over a broad frequency range. Art-Composite combines dense, limp, flexible, non-lead loaded barriers with Acousti-Mat foams providing a total noise control system. Unlike other composites available, these multilayer systems are manufactured without costly adhesives, thus eliminating the potential for failure between layers. Art-Mat acoustical foams are designed to provide maximum absorption of airborne sound with minimum thickness and weight. These flexible polyurethane open cell foam products are manufactured to optimize pore size, air flow resistance, and density. Sound energy, passing through the cell structure, is converted into minute quantities of low grade heat that is easily dissipated. Since the uniformity of the cells are carefully controlled the efficiency is constant and predictable from one installation to another. ArtUSA Panels provide excellent sound absorption, especially in environments requiring high frequency noise control. Made with ArtUSA exclusive willtec® foam, ArtUSA Acousti™ Mini Panels are a safety-minded choice for use in machine enclosures and other confined spaces. Willtec foam is Class 1 fire-rated according to ASTM E 84 for flame spread and smoke density. It can withstand constant temperatures above 300° Fahrenheit, and will char but not ignite at temperatures above 1100° Fahrenheit. Willtec natural meets the corner burn test UL1715. We sell and install SONEX, Pinta, Ilbruck, ward, and Techni foam.
 

Noise Control for Architects - Acoustical Panels and Fabric Covered Absorbers and Blockers

With a custom look, durable construction and excellent acoustical control, ArtUSA Acousti™ Wall Panels easily add style and performance to: schools, gymnasiums, restaurants, offices, auditoriums, entries and other noisy open areas. Specify standard or custom sized Acousti™ Panels to create a design that perfectly fits your space. Select from our fashionable Guilford FR701 fabrics or durable microperforated vinyl coverings — a breeze to clean, they’re perfect for protecting high traffic areas. And finish the look by choosing squared or full beveled edges. ArtUSA Acousti™ Wall Panels are just as easy to install as they are to specify. Built from a unique willtec® foam core, they have outstanding acoustical performance and feather-light weight. Acousti™ Panels also have a high impact, tackable surface, which further enhances their practicality. Functional. Stylish. Simple. ArtUSA Acousti™ Wall Panels are the superior solution for adding texture, color and acoustical balance to your designs-Artusa Acousti™2500 Noise Barrier Wall Panels are the solution for areas that require noise reduction and are available in a variety of models for various applications. The Acousti™-2500 Wall Panel is manufactured specifically as a noise barrier/absorber panel that offers both superior absorption and noise blocking performance. Application for the Acousti™-2500 Panels includes corporate offices, conference rooms, doctor’s offices, waiting rooms, classrooms and any area where speech privacy is a concern. ArtUSA Acousti™ -2500 Noise Barrier Wall Panels are the solution to speech privacy problems, providing clients the confidence that confidential conversations will not be overheard. Acousti™-2500 Wall Panels are constructed using 2 layers of a 6-7# PCF rigid fiberglass core between a 1 lb per square foot non-reinforced loaded vinyl noise barrier. Panels are available in 1 1/8” and 2 1/8” thickness, with a maximum size up to 4’ X 10’and may be finished in custom, designer or C.O.M. fabric. Acousti™-2500 Wall Panels can be installed with impaling clips, top hook and construction adhesive. Due to panel weight 2.5 lb per square foot, panels must be installed from floor to ceiling. Floor molding can be re-installed after installation of Acousti™-2500 Wall Panels

Noise Control for Industrial equipment  Silencers and Attenuators

Once and adequate enclosure is in place the silencing of equipment installations in industrial environments is basically a problem of attenuating the noise from the atmospheric inlet and the exhaust openings. ArtUSA Acoustics sound attenuators and silencers are engineered to achieve a maximum insertion loss with a minimum pressure drop and feature airfoil design for efficient aerodynamic performance, as well as superior acoustical materials and totally galvanized steel construction. ArtUSA Acoustics sound attenuators and silencers are designed and engineered to eliminate acoustical fill entrainment by the air stream and reduce to a minimum the absorption of gases and particles by the acoustical fill. Reliability and performance are guaranteed since the best basic configuration and materials are utilized. ArtUSA intake and/or discharge silencers work on blowers, compressors, engines, vacuum pumps and gas vents. Since its inception ArtUSA has tackled silencing problems covering the entire spectrum of industries and applications. Our acoustical and mechanical engineers can design complete air inlet silencing systems, including filter houses of various configurations.

• Noise Pollution Clearinghouse
• Acoustical Society of America
• American Speech Language Hearing Association
• Institute of Noise Control Engineering of the U.S.A.
• National Council of Acoustical Consultants
• The National Hearing Conversation Association
• National Institute for Occupational Safety and Health
• OSHA – Noise and Hearing Conservation
• Other Links - Home Theater, Music and Construction Resources