Across
- 5. to protect our ears from loud sound
- 6. sound travels fastest
- 7. units of sound
- 8. sound travel slowest
- 9. produce high pitch
- 11. sound cannot travel
Down
- 1. when an object vibrates
- 2. material that can reduce the loudness
- 3. loud or soft sound
- 4. high or low sound
- 10. produce low pitch