| A | B |
|---|
| intensity | The strength of a sound wave |
| decibel | the most commonly used unit of sound intensity |
| infrasonic | sounds with pitches below the audible range |
| ultrasonic | sounds with pitches above the audible range |
| Doppler effect | the change in frequency caused by an object's motion |
| audible sound | sound that can be heard |
| loudness | teh effect of intensity on the way the ear perceives sound |
| pitch | the effect of frequency on the way the ear perceives sound |
| tuning fork | a well-known device for producing pure musical sounds of a definite pitch |
| 25 | according to inverse wquare law of sound intensity, the intensity of a certain at a distance of 2 meters is ___ times as intense as the same sound at a distance of 10 meters. |
