| A | B |
|---|
| loudness | the human perception of how much energy a sound wave carries. |
| pitch | how high or low a sound is. |
| echo | a reflected sound |
| Doppler Effect | change in the frequency or pitch of a sound that occurs when the sound source and the listener are in motion relative to each other. |
| natural frequency | frequency at which a musical instrument or other objects vibrates when it is struck or distributed; relative to its size, shape, and the material it is made from. |
| resonance frequency | sound amplification that occurs when an object is vibrated at its natural frequency by absorbing energy from a sound wave or other object vibrating at this frequency. |
| overtone | multiples of the fundamental frequency. |
| reverberation | repeated echoes of sounds. |
| eardrum | membrane stretching across the ear canal that vibrates when sound waves reach the middle ear. |
