|
Aircraft noise is defined as sound produced by any aircraft on run-up, taxiing, take off, over flying or landing. Aircraft noise is a significant concern for approximately 100 square kilometers surrounding most major airports. Aircraft noise is the second largest (after roadway noise) source of environmental noise. While commercial aviation produces the preponderance of total aircraft noise, private aviation and military operations also play a role. A schematic representation of hearing. ...
Roadway noise is the most prevalent form of environmental noise Roadway noise is the collective sound energy emanating from motor vehicles. ...
Environmental Noise, is unwanted sound, which may cause either nuisance or damage to health. ...
Aviation or Air transport refers to the activities surrounding mechanical flight and the aircraft industry. ...
Private Aviation Private aviation encompasses everything from large corporate jets all the way down to the individual who owns and operates their own small aircraft, such as a Cessna or Cirrus SR-22. ...
Take-off of aircraft may lead to a sound level of more than 100 dBA at the ground, with approach and landing creating lower levels. Since aircraft landing in inner-city airports are often lower than 60 meters above roof level, a sound level above 100 dBA can be realized. DBA has several meanings: database administrator (or analyst) De Bellis Antiquitatis, a tabletop wargame. ...
Mechanisms of sound production
A moving aircraft including the jet engine or propeller causes compression and rarefaction of the air, producing motion of air molecules. This movement propagates through the air as pressure waves. If these pressure waves are strong enough and within the audible frequency spectrum, a sensation of hearing is produced. Different aircraft types have different noise levels and frequencies. The contributions to the total noise level originate from three main sources: A Pratt and Whitney turbofan engine for the F-15 Eagle is tested at Robins Air Force Base, Georgia, USA. The tunnel behind the engine muffles noise and allows exhaust to escape. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...
- Aerodynamic noise
- Engine and other mechanical noise
- Noise from aircraft systems
Aerodynamic noise Aerodynamic noise arises from the airflow around the aircraft fuselage and control surfaces. This type of noise increases with aircraft speed and also at low altitudes due to the density of the air. Jet-powered aircraft create intense noise from aerodynamics, which is typically broadband. Low flying, high speed military aircraft produce especially loud aerodynamic noise. (Even though cabin sound levels may be lower in civilian commercial airliners due to added sound attenuating material, it should be noted that this exposure can lead to damage, since hearing loss is cumulative.) In an aircraft, the fuselage is the main body section that holds crew and passengers or cargo. ...
Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ...
Broadband in general electronics and telecommunications is a term which refers to a signal or circuit which includes or handles a relatively wide range of frequencies. ...
The shape of the nose, windshield or canopy of an aircraft can greatly affect the sound produced. Much of the noise of a propeller aircraft is of aerodynamic origin due to the flow of air around the blades. The helicopter main and tail rotors also give rise to aerodynamic noise. This type of aerodynamic noise is mostly low frequency determined by the rotor speed. The raised canopy of a Vans RV-7A A canopy is the transparent enclosure over the cockpit of an aircraft. ...
The Bell 206 of Canadian Helicopters Robinson Helicopter Company (USA) R44, a four seat development of the R22 A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors. ...
Engine and other mechanical noise Much of the noise in propeller aircraft comes equally from the propellers and aerodynamics. Helicopter noise has a unique spectral content, essentially being aerodynamically induced noise from the main and tail rotors and mechanically induced noise from the main gearbox and various transmission chains. The mechanical sources produce narrow band high intensity peaks relating to the rotational speed and movement of the moving parts.
Noise from aircraft systems Cockpit and cabin pressurisation and conditioning systems are often a major contributor within cabins of both civilian and military aircraft. However, one of the most significant sources of cabin noise from commercial jet aircraft other than the engines is the Auxiliary Power Unit (or APU). An Auxiliary Power Unit is a relatively small self contained generator used in aircraft to start the main engines, usually with compressed air, and to provide electrical power while the aircraft is on the ground. The typical noise output of an APU is 113 decibels. This is about 27 decibels lower than that of a jet engine. Other internal aircraft systems can also contribute, such as specialised electronic equipment in some military aircraft. Look up Pressurization in Wiktionary, the free dictionary. ...
Supersonic boom
Annoyance effects Lesser intensities of noise are produced for cruising velocities, mainly due to the altitudes of operation. However, this noise often is heard in country settings which are by nature very peaceful. Thus the intrusion of this type of noise can be very intrusive even if much less in amplitude (say approximately 45 decibels). Landing aircraft descend on a three degree glide path towards an aiming point approximately 300 meters from the runway threshold. This places them at 60 meters above the ground at about 1200 meters from the aiming point or 900 meters from the start of the runway. This distance is usually outside the airport fence. Departing aircraft normally are over 150 meters above the ground before crossing the end of the runway.
 A British Airways Airbus A321, on landing approach to London Heathrow Airport, showing proximity to homes. British Airways Airbus A321 flies over Myrtle Avenue on its landing path to Heathrow runway 27L. Myrtle Avenue is on the south east edge of London (Heathrow) Airport. ...
British Airways Airbus A321 flies over Myrtle Avenue on its landing path to Heathrow runway 27L. Myrtle Avenue is on the south east edge of London (Heathrow) Airport. ...
Health effects of aircraft noise - main article: Noise health effects
The annoyance effects of aircraft noise are widely recognized; however, aircraft noise is also responsible for a significant amount of hearing loss as well as a contributor to a number of diseases. Only in the early 1970s did aircraft noise become a widespread topic of concern in the U.S. and federal regulations began to recognize the significance of abating these impacts in the vicinity of major commercial airports. High levels of aircraft noise that commonly exist near major commercial airports are known to increase blood pressure and contribute to hearing loss. Some research indicates that it contributes to heart diseases, immune deficiencies, neurodermatitis, asthma and other stress related diseases. Further research is being carried out to better understand these effects. Environmental noise can produce irreversible hearing loss Noise health effects, the collection of health consequences of elevated sound levels, constitute one of the most widespread public health threats in industrialized countries. ...
Blood pressure is the pressure exerted by the blood on the walls of the blood vessels. ...
Hearing impairment or deafness is decreased or absent ability to perceive auditory information. ...
Heart disease is one of a number of different diseases which afflict the heart. ...
A request has been made on Wikipedia for this article to be deleted in accordance with the deletion policy. ...
This article needs to be cleaned up to conform to a higher standard of quality. ...
Prior research indicates clearly that hearing loss is less a product of aging than a result of exposure to transportation related noise (Rosen, 1965). Any sound louder than normal conversation can damage the delicate hair cells in the cochlea, the structure in the inner ear that converts sound waves into auditory nerve signals. Initially damage to the cochlea may be temporary, but with repeated exposure, the damage becomes permanent and tinnius maybe develop. More recently the Centers for Disease Control and Prevention's (CDC) National Center for Environmental Health (NCEH) conducted an analysis to determine the prevalence of hearing loss among children using data collected from 1988-1994 in the Third National Health and Nutrition Examination Survey. The analysis indicates that 14.9% of U.S. children have low or high frequency hearing loss of at least 16 dB hearing level in one or both ears. Hearing impairment or deafness is decreased or absent ability to perceive auditory information. ...
Cross section of the cochlea. ...
The auditory nerve is the nerve along which the sensory cells (the hair cells) of the inner ear transmit information to the brain. ...
The Centers for Disease Control and Prevention (CDC) in Atlanta is recognized as the lead United States agency for protecting the public health and safety of people by providing credible information to enhance health decisions, and promoting health through strong partnerships with state health departments and other organizations. ...
From research of the National Institutes of Health, roughly 65 million Americans are exposed to sound levels that can interfere with their function at work or disrupt sleep, and 25 million are exposed to health risk (cardiovascular, immunological, etc.) from environmental noise. The National Institutes of Health (NIH) is the primary agency of the United States government responsible for medical research. ...
The circulatory system or cardiovascular system is the organ system which circulates blood around the body of most animals. ...
Immunology is a broad branch of biomedical science that covers study of all aspects of the immune system in all organisms. ...
Noise mitigation programs - main article: Noise mitigation
In the United States, since aviation noise became a major public issue in the late 1960s, governments have enacted legislative controls. Aircraft designers, manufacturers, and operators have developed quieter aircraft and more careful operating procedures. Modern high-bypass turbofan engines, for example, are quieter than the turbojets and low-bypass turbofans of the 1960s; however, due to expanded numbers of flights, there is no clear trend of aircraft noise reduction for land uses near airports. Roadway noise is the most pervasive form of environmental noise Noise mitigation is a set of strategies to reduce unwanted environmental sound. ...
The 1960s decade refers to the years from 1960 to 1969, inclusive. ...
CFM56-3 turbofan, lower half, side view. ...
Turbojets are the simplest and oldest kind of general purpose jet engine. ...
Since abatement of aircraft noise has not been very effective at the source, in the 1980s the U.S. Congress authorized the FAA to devise technology and programs to attempt to insulate homes near airports. While this obviously does nothing for the exterior environment, the program has been effective for residential interiors. Some of the first airports at which the technology was applied were San Francisco International Airport and San Jose International Airport in California. The underlying technology is a computer model which simulates the impingement of aircraft noise upon building structures. One can examine variations in aircraft types, flight patterns and local meteorology. then one can evaluate the benefits of alternative building retrofit strategies such as roof upgrading, window glazing improvement, fireplace baffling, caulking construction seams and other measures. The computer model allows cost effectiveness evaluations of unlimited numbers of strategy combinations (Hogan, 1984). The Congress of the United States is the legislative branch of the federal government of the United States of America. ...
FAA may refer to: Federal Aviation Administration in the United States Fleet Air Arm in the UK Royal Navy Fuerza Aérea Argentina in Argentina This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...
FAA diagram of SFO SFO redirects here. ...
The Norman Y. Mineta San José International Airport (IATA: SJC, ICAO: KSJC) is a medium-sized airport in San José, California. ...
Glazing, in architecture, is a transparent part of a wall, usually made of glass or plastic (acrylic and polycarbonate). ...
Bibliography - Michael Hogan, Design of acoustical insulation for existing residences in the vicinity of San Jose Municipal Airport, January 1, 1984, FAA grant funded research, ISBN B0007B2OG0
- U.S. Noise Control Act of 1972 United States Code Citation: 42 U.S.C. 4901 to 4918
In communications, a code is a rule for converting a piece of information (for example, a letter, word, or phrase) into another form or representation, not necessarily of the same sort. ...
Hearing impairment or deafness is decreased or absent ability to perceive auditory information. ...
Coronary heart disease (CHD), also called coronary artery disease (CAD) and atherosclerotic heart disease, is the end result of the accumulation of atheromatous plaques within the walls of the arteries that supply the myocardium (the muscle of the heart). ...
See also A hush kit is a device for reducing noise from an engine; most commonly the term refers to devices which reduce noise emissions from turbojets. ...
This article is a physical description of hearing impairment. ...
Helicopter noise reduction is a topic of research into designing helicopters which can be operated more quietly, reducing the public-relations problems with night-flying or expanding an airport. ...
Noise barrier earth berm along Highway 12, Sonoma County, California A noise barrier is an exterior structure, normally made of masonry or earth, designed to protect sensitive land uses from noise pollution. ...
Noise pollution is unwanted human-created sound that disrupts the environment. ...
The United States Capitol building, where the first national Noise Control Act was passed. ...
Tinnitus, ringing ears or ear noise is a phenomenon of the nervous system connected to the ear, characterised by perception of a ringing or beating sound (often perceived as sinusoidal) with no external source. ...
External links - Federal Interagency Committee on Aviation Noise (FICAN)
- Aviation Environment Federation (AEF)
|
Feeds |
Contact