| A | B |
|---|
| Infrasonic | sounds with frequecies lower than 20Hz |
| Ultrasonic | sounds with frequencies that are higher than 20,000Hz |
| Doppler effect | The apparent change in the frequency of a sound caused by the motion of either the listner or the source of the sound |
| Decibel | most common unit used to express loundess |
| Noise | any undesired sound |
| Echolocation | The process of using reflected sound waves to find objects |
| Sonic boom | The explosive sound heard when a shock wave reaches your ears |
| Sound quality | Several pitches blending together through interference |
| echo | Reflected sound |
