Sound waves

5. All sound waves needs a _____________ to travel through.
6. Sounds with frequencies below the normal human range of hearing are called __________________.
8. Sound waves with frequencies above the normal human range of hearing are called _______________.
10. ____________ is how fast a wave travels.
11. ____________________ interference occurs when the compression of 1 wave overlap with the compression of another wave = LOUDER
13. _____________ is a disturbance that travels through a medium as a longitudinal wave.
14. A reflection sound wave is called an _______________.
17. ________________ is the combination of the 2 or more waves to form a single wave.
18. when sound waves leave its source, the waves travel in all ______________ away from the source.
19. sound waves are ___________ waves.
20. The loudness of the different sounds is compared using a unit called _______________ (dB).
23. _________________ interference occurs when the compression of 1 wave overlap with the rarefactions of another wave = SOFTER
24. At low temperatures, particles in a medium move more slowly than at ___________ temperatures.
25. Soft/bumpy surface ____________ or scatter the reflection.

1. The bouncing back of a wave after it hits a barrier is called a _________________.
2. The pitch of a sound depends on the _________________ of a wave.
3. The harder and smoother the surface the ______________ the reflection.
4. ________________ is the apparent change in the frequency of a sound cause by the motion of either the listener or the source of the sound.
7. The higher the decibel ____________, the louder the sound.
9. Loudness is related to the _______________ of the wave.
12. ______________ is a measure of how well something can be heard.
15. Sounds travel more slowly at ______________ temperatures than higher temperatures.
16. ______________ are the complete back and forth motion of an object.
21. ___________ is how high or low something sounds.
22. The speed of sound ___________ on the medium that is travel through.