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NEF
- Usado para
- noise exposure forecast
- Definição1
- The total summation (on an energy basis) over a 24 hour period (weighted for the time of day) of effective perceived noise level (EPNL) minus the constant 88 dB. NEF is used to determine the relative noise impact of aircraft noise near an airport.
- Fonte1
- MULTILINGUAL aeronautical dictionary, or, dictionary aeronautique multilingue: english, french, spanish, dutch, greek, italian,portuguese, turkish. London, England: Technical Editing and reproduction Ltd, 1980. xx, 876 p. ISBN 92835016667
- Fonte2
- ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS. NBR 11415: ruído aeronáutico: terminologia. Rio de Janeiro, 1990. 15 p.
- Nota adicional1
- Several mathematical models have been developed to express the combined effect of the variables that influence human response to noise as a single index. One model, the Noise Exposure Forecast (NEF), has been adopted in Canada for controlling land use in the vicinity of airports. NEF contours are set around airports and include levels beyond which noise, as defined by NEF values, will not be tolerated. The contours generated by the model are generally drawn for the 40, 35, 30, 28 and 25 NEF levels and are used only as a guide. Sociological surveys indicate that below 30 NEF, sporadic complaints may occur and noise may interfere with certain residential activities. Above 30 NEF, complaints may become increasingly vigorous and take the form of group action. And, above 40 NEF, legal action may be expected. NEF values do not indicate real noise levels but, rather, are a measure of the likely psychological response of an affected community to the actual noise generated by aircraft movements at a particular location near an airport. The methodology used to determine these values does not consider such factors as differences in actual runway usage and flight paths from those assumed in NEF calculations; variations in noise transmission under different atmospheric conditions; helicopter movements; noise generated during taxiing; or differences in respondents' life styles. In Canada, official NEF contours are prepared by Transport Canada and are published by the Central Mortgage and Housing Corporation as a guide for land use planners. There is no statutory requirement to comply with these standards, nor is an airport legally required to operate in the manner assumed for purposes of preparing the noise forecasts. The significant NEF value for the Toronto Island Airport is 28, as stated in the Tripartite Agreement, which defines the maximum level of noise-related activity permitted while remaining tolerable to residents. According to the official 1990 NEF contour map there are no residents living within the 28 NEF contour.
- Português
- nível de incômodo sonoro pelo método noise exposure forecast