Train noise

Train noise is vehicle noise created by trains. Noises may be heard inside the train and outside. 
Subway systems, light rail transit and freight trains can send loud train noise into neighborhoods. Organizations such as the World Health Organization and the U.S. Environmental Protection Agency have set guidelines for noise level decibel limits for rapid transit. Noise levels can be reduced by installing noise barriers next to the track.
Sources.
Several distinct sounds are created by various parts of the train, such as engines, traction motors, brakes, and the wheels turning on the rails.
References.
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