| A | B |
|---|
| compression | region of crowded particles |
| rarefaction | region of fewer particles than usual |
| transmitted | energy passed through matter |
| absorbed | energy trapped in matter |
| reflected | energy that is bounced back |
| wavelength | distance from one crest to another crest |
| frequency | number of waves that pass a point in a certain time |
| pitch | how high or low a sound seems |
| Doppler effect | the relationship between pitch and motion |
| amplitude | amount of energy in a wave |
| noise | unpleasant sound |
| supersonic | speeds greater than the speed of sound |
| Mach number | compares speeds of objects that travel faster than sound |
| ultrasonic | sounds with frequencies above 20000 cycles per second |
| sonar | high frequency sound used to locate fish |
| decibels | units used to measure sound |
