1. HOW DO WE PERCEIVE PITCH??!
BY: DEJONA HAWKINS
PRD. 7

2. HIGH PITCHED: LOW PITCHED: Chirp of a bird Roar of a truck

3. Place theory
We hear different pitches because different sound waves trigger activity at different places along the cochlea’s basilar membrane

4. High frequencies produce large vibrations near the beginning of the cochlea’s membrane, low frequencies near the end.

5. Frequency theory
Suggests an alternative explanation for how we detect pitch
How we perceive low pitch sounds
Depends on sound waves Also known as the theory.

6. Individual neurons can’t fire
faster than
times per second!!!

7. Like soldiers who alternate firing so that some can shoot while others reload, neural cells can alternate firing.

8. How do we locate
sounds??!

9. Sound waves strike one ear sooner and more intensely than the other.

10. WHY DON’T WE HAVE ONE EAR??!
“THE BETTER TO HEAR YOU”

11. Allows you to enjoy stereophonic hearing!

12. TWO EARS ARE BETTER THAN ONE 4 THIS REASON
IF A CAR TO THE RIGHT HONKS, YOUR RIGHT EAR RECEIVES A MORE INTENSE SOUND AND IT RECEIVES SOUND SLIGHTLY SOONER THAN YOUR LEFT EAR.

13. SOUND TRAVELS 750 MPH
OURS EARS ARE 6 INCHES APART
INTENSITY DIFFERENCE AND TIME LAG ARE EXTREMELY SMALL

14. LAST
DO YOU THINK WE DO WELL WITH HEARING A SOUND FAR AWAY THEN A SOUND AHEAD, BEHIND, OVERHEAD OR BENEATH??
The answer is….

15. EXAMPLE

16. SOME BRAIN NEURONS RESPOND MORE TO A HIGH-CONTRAST SOUND STIMULUS, AS MIGHT BE MADE BY A MUSICAL INSTRUMENT PLAYING SOLO
OTHERS RESPOND MORE TO LOW-CONTRAST SOUND, AS WOULD BE MADE BY THE SAME INSTRUMENT PLAYING IN AN ORCHESTRA.