In earlier times people used to listen for the arrival of a distant train by putting their ear to the rail
Answers
In olden times the speed of the trains was lesser than the present times. It is said that cowboys used to put their ear to a railway track to hear if a train was coming. The reason for this is that the speed of sound waves depends on the material through which they are travelling. Sound travels fifteen times faster through the metal railway tracks than through the air. So the cowboys could get an early warning about a train's arrival.
Actually it was not necessary to put one's ear on the track. A person could place one end of a solid piece of wood or metal firmly on the track and place his ear on the other end.
The train run on rail and its wheel bang on rail and the friction occurs.
These produces vibration and the sound is produced.
The sound travel over a large distance through the rail.
If the year is put to the Rain sound can be clearly heard at the arrival of a train can be guessed.