How sound waves are made
Vibration of an object is what produces sound waves. The vibrating object moves in one direction and compresses the air directly in front of it. The vibrating object moves in one direction and compresses the air directly in front of it. As the vibrating object moves in the opposite direction, the pressure on the air is lessened so that an expansion, or rarefaction, of air molecules occurs.
How many directions can a vibrating sound wave travel at a time?