| A | B |
|---|
| Vibration | A back and forth motion. |
| Sound Wave | A vibration that spreads away from a vibrating object. |
| Matter | A solid, liquid or gas that takes up space, has mass, and properties you can observe and describe. |
| Medium | A substance through which something is transmitted or carried. |
| Compression | The part of a sound wave where molecules are crowded together. |
| Rarefaction | The part of a sound wave where molecules are spread apart. |
| Pitch | How high or low a sound is. |
| Frequency | The number of times an object vibrates per second. |
| Hertz | A unit for measuring frequency. One unit equals a frequency of one vibration per second. |
| Volume | The loudness or softness of a sound or signal. |
| Decibel | A unit that measures loudness. |
| Reflection | The bouncing off or turning back of a sound wave from a surface. |
| Absorption | The disappearance of a sound wave into a surface. |
| Echo | A reflected sound wave. |
| Echolocation | Finding an object by using reflected sound. |
| Sound | energy created from vibrating objects |
