| A | B |
|---|
| Empty Space | Part of the universe that has no matter or air |
| Compressional wave | Wave in which matter vibrates in the same direction as the energy waves traveling through it |
| Compression | Making something smaller or shorter by pressing or squeezing |
| Pitch | The highness or lowness of a sound |
| Intensity | A measure of the amount of energy in a wave |
| Decibel | The unit for measuriing the volume or loudness of a sound |
| Echo | A sound that bounces back from a distant object |
| Sonar | A device which uses sound waves to measure distance |
| Music | Pleasant sound with regular wave patterns |
| Noise | Sound with no regular wave patterns |
| Octave | A musical sequence in which the top note has twice the frequency of the bottom note |
