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The END gives a common approach intended to avoid, prevent or reduce the harmful effects of environmental noise. The main target is an integrated noise management. In the first step the competent authorities in the European member states had to produce strategic noise maps for major roads, railways, airports and agglomerations. The second step ...
Noise measurement can also be part of a test procedure using white noise, or some other specialized form of test signal.In audio systems and broadcasting, specific methods are used to obtain subjectively valid results in order that different devices and signal paths may be compared regardless of the inconsistent spectral distribution and temporal properties of the noise that they generate.
Higher ambient noise levels also cause animals to vocalize more loudly, which is called the Lombard effect. Researchers have found that humpback whales' song lengths were longer when low-frequency sonar was active nearby. [82] Underwater noise pollution is not only limited to oceans, and can occur in freshwater environments as well.
The term "cumulative" EPNdB is the combination of the noise margins from the three ratings. It is defined as the sum of the individual margins (difference between certified noise level and noise limit) at takeoff lateral, takeoff flyover and approach. [4] It is important to make the distinction between loudness and noisiness.
Noise-generating aircraft propeller. Aircraft noise is noise pollution produced by an aircraft or its components, whether on the ground while parked such as auxiliary power units, while taxiing, on run-up from propeller and jet exhaust, during takeoff, underneath and lateral to departure and arrival paths, over-flying while en route, or during landing.
strategic noise map shall mean a map designed for the global assessment of noise exposure in a given area due to different noise sources or for overall predictions for such an area." EU Member States are required to produce strategic noise maps in their main cities, near the main transport infrastructure and industrial sites. The main goals of ...
Ambient noise level is measured with a sound level meter. [4] It is usually measured in dB relative to a reference pressure of 0.00002 Pa, i.e., 20 μPa (micropascals) in SI units. [5] This is because 20 μPa is the faintest sound the human ear can detect. [5] A pascal is a newton per square meter. The centimeter-gram-second system of units ...
The day-night average sound level (Ldn or DNL) is the average noise level over a 24-hour period. The noise level measurements between the hours of 22:00 and 07:00 are artificially increased by 10 dB before averaging. This noise is weighted to take into account the decrease in community background noise of 10 dB during this period.