Sound Transmission

In order to produce sound, a vibrating object and a medium that carries the sound waves are needed. Sound waves may be carried by solids, liquids, or gases. Because they rely on matter, sound waves cannot travel through a vacuum, or an area where no matter is present.

Although air carries most of the sounds on Earth, sound travels faster in water than in air. This explains the fact that whales can communicate with one another over great distances.

Like light, sound can also be absorbed and reflected. When a sound strikes a surface, some of it is reflected and some penetrates the surface. The sound that penetrates is called absorbed sound. The sound that is reflected is called an echo. Try to shout in an enclosed room with no windows. What do you notice? What do you hear?