We are all familiar with waves; from ripples on the surface of a pond to the swell of the ocean. A wave is just a regular vibration that travels through something, like air or water. Sound is one type of wave. When someone speaks, the waves are made in their throat and travel out to the listener's ear. It is then the ear's job to change that wave in the air into a signal that can be understood by the brain. Sound waves need support - a medium - to travel.