Vibrations from objects like vocal cords, tuning forks, or speakers cause the air particles around them to vibrate, creating regions of compression and rarefaction that form sound waves which travel through the air and enter the ear. The vibration is transferred through the air particles hitting one another in a continuous pattern of compression and rarefaction called a sound wave. This vibration of air particles is the second step in hearing sound.

1. Sound

2. How do we hear sound?
3 steps occur to hear sound

3. How do we hear sound?
First
The object that sound comes from
vibrate.

4. Example 1

5. Example 1
The vocal cords vibrate so sound is
produced.

6. Example 2
Tuning fork

7. Example 3
Speakers

8. Watch video of instruments vibrating

9. Conclusion
Sound results from vibration

10. How do we hear sound?
second
The vibration is transferred to the
air.

11. The air contains atoms or
particles, these particles hit
each other.

12. Watch video of air particles

14. Compression
Regions of air that have
many particles

15. Rarefaction
Regions of air that have few
particles

16. The continous compression and
rarefaction of air particles is called
Sound wave