Sound Waves are what sound travels in! They are little vibrations of air that travel through a medium or a material that it is travelling through. Sound Waves are why you can hear a jackhammer or my podcast!! First, an object or person has to make a sound. A sound is made by an object vibrating back and forth. When the object vibrates, the air around it starts to move. The molecules of air bump into each other. This causes a wave of air molecules. This wave continues until it reaches your ear!! This is how sound waves work!