Sound is Produced by a Vibrating Body
Sound is a pressure disturbance that moves through a medium in the form of mechanical waves. When a force is exerted on an atom, it moves from its rest or equilibrium position and exerts a force on the adjacent particles.
These adjacent particles are moved from their rest position and this continues throughout the medium. This transfer of energy from one particle to the next is how sound travels through a medium.
The words "mechanical wave" is used to describe the distribution of energy through a medium by the transfer of energy from one particle to the next.
Sound waves that travel parallel to the direction of the particle movement are called longitudinal waves.
However, it is possible to produce other types. Waves which move perpendicular to the direction of particle movement are called transverse waves.
After the train crosses the station, if you keep your ear on the rail track, you can clearly hear the vibrations in the rail track. This confirms that sound travels through solids.