Acoustics term

3. The mechanical vibrations of sound move forward using wave motion
5. is the distance moved per second in a fixed direction. The unit is metres per second
9. occurs when the natural frequency of an object coincides with the frequency of any vibrations applied to the object
12. is the range of frequencies between any one frequency and double that frequency
14. travels faster in liquids and solids than it does in air
15. frequency too high for human hearing
18. frequency too low for human hearing
19. compresses adjacent particles of air as it moves in one direction and leaves the particles of air ‘spread out’ as it moves in the other direction

1. is the distance between any two repeating points on a wave. The unit is the metre
2. the nature of a sound wave, such as shown in the earlier figure, means that the vibration of the wave has alternate changes in amplitude called phases
4. high frequency
6. A pure tone is sound of only one frequency, such as that given by a tuning fork or electronic signal generator
7. include loudspeakers, guitar strings, vibrating walls and human vocal chords
8. is the number of cycles of vibration per second. The unit is the hertz
10. include horns, organ pipes, mechanical fans and jet engines
11. low frequency
13. is independent of the rate at which the sound vibrations occur, which means that the frequency of a sound does not affect its speed
16. is the frequency of a sound as perceived by human hearing
17. Sound is a variation in the pressure of the air of a type which has an effect on our ears and brain