Every time a sound is produced it emits a sound wave. You can picture the shape of sound as a wave on the ocean: the sound starts at one end of the wave and spreads out. By the time the wave reaches the shore you can hear it.
For a home example of this phenomenon, take a rubber band and spread it tightly between your fingers. Now strum the rubber band. The movement of the band creates vibration, or sound waves. This experiment will demonstrate how sound travels, using nothing more than a spoon and a string.