Train noise is vehicle noise created by trains. Noises may be heard inside the train and outside. Various parts of a train produce noise, and different kinds of train wheels produce different amounts of noise. Noise barriers can attenuate the noise.
Train noise can be a type of environmental noise. When a train is moving, there are several distinct sounds such as the locomotive engine noise and the wheels turning on the railroad track. The air displacement of a train or subway car in a tunnel can create different whooshing sounds.
Trains also employ horns, whistles, bells, and other noisemaking devices for both communication and warning.
Trains propelled by electric traction motors often produce a noise in which the relative pitch corresponds to the speed & the volume to the power being used. The noise made depends on the type of motor (e.g. that of AC motors is usually higher than that of DC motors). Variable frequency drives can produce a high- & fixed-pitched whining noise, while DC pulse width modulation has a buzzing noise corresponding to the frequency.
Flange Squeal is a definition used to describe the sound of the ridges of the metal train wheels turning on the train track.