| A | B |
|---|
| echo | a reflected sound wave |
| elasticity | the ability of a material to bounce back after being disturbed |
| density | how much matter (or mass) there is in a given amount of space (volume) |
| loudness | the way we perceive (or hear) the energy (or amplitude) of a sound wave |
| intensity | the amount of energy a sound wave carries per second through a unit area |
| decibel (dB) | a unit used to compare the loudness of different sounds |
| pitch | the way we describe how high or low a sound seems |
| ultrasound | sound waves with frequencies above or beyond the normal human range of hearing |
| infrasound | sound waves with frequencies below the normal human range of hearing |
| larynx | the voice box; the location of the vocal cords that help us make sounds and speech |
| Doppler effect | the change in frequency, heard as a change in pitch, of a wave as its source (what makes the wave) moves toward or away from a person |
