Sound wave

A vibrating solid, such as a tuning fork, pushes and pulls on the air beside it. This creates successive compressions and rarefactions that travel away as a sound wave. In both directions, a wave disturbance transfers energy between a material and a vibrating solid.

When a guitar string is plucked, it moves back and forth and disturbs the air beside it. That disturbance travels through the air as a sound wave: the air particles vibrate, but the air itself does not travel all the way from the guitar to the listener. Vocal cords and a loudspeaker cone also set the surrounding air vibrating.

The cone’s movement produces sound waves in the surrounding air. Sound reaching your ear then makes another solid structure—the eardrum—vibrate. These are examples of energy passing between a sound wave and vibrations of solid material, rather than the material itself travelling with the wave.

The vibration is therefore passed through the material as a sound wave. OCR states that sound travels better through solids and liquids than through air.