1. Sound Properties and Interactions

2. How Do We Produce Sounds? Vibrations are key!!!!! Vibrations: the complete back-and- forth motion of an object

3. Example of a Speaker A.Vibrations begin at the source…the speaker B. Vibrations move in waves…away from the source C.V ibrations continue to move in waves away from the source…in compressions and rarefactions

4. Sound Waves are Longitudinal Remember COMPRESSIONS and RAREFACTIONS!!!! SOURCE Rarefactions Compressions

5. Need For A Medium Medium: a substance through which a wave can travel Solid, Liquid, Gas Sound cannot travel in a VACUUM !!!!

6. Speed of Sound The speed of sound depends on the medium The speed of sound is constant through a medium as long as the properties of the medium are constant

7. Changing The Speed Of Sound The biggest property of change is TEMPERATURE!!! Colder the medium = the slower the speed of sound

8. Whudyou’ Say Willis?

9. What!?!?!?

10. Yeah!!!!! When you listen to things at too loud a level…these cilia (hairs) continue to vibrate and lead to a ringing in your earsWhen you listen to things at too loud a level…these cilia (hairs) continue to vibrate and lead to a ringing in your ears

11. Pitch Pitch: how low or high you perceive a sound to be Depends on Frequency

12. Frequency and Hearing

13. Doppler Effect Doppler Effect: The apparent change in the frequency of a sound caused by the motion of either the listener or the source of the sound The frequency doesn’t actually change…its only sounds like it does

14. Loudness Loudness: how loud or soft a sound is perceived to be Larger amplitude = Louder Sound

15. Reflection of Sound Waves Reflection: the bouncing back of a wave after it strikes a barrier Example: Echo

16. Echolocation Echolocation: the process of using reflected sound waves to find objects Uses: animals such as dolphins, bats, and birds use this to hunt food and detect objects in their way

17. Echolocation and Bats

18. Echolocation Technology Sonar: Sound Navigation And Ranging Sonar allows navigators on ships detect icebergs and can help oceanographers map the ocean floor

19. Resonance Resonance: occurs when an object vibrating at or near a natural frequency of a second object causes the second to vibrate