1. Hearing
Ear Anatomy
Dancing hair cell

2. Hearing
High amplitude F0

3. Hearing
Low amplitude F0

4. Hearing
So, what determines the perceived pitch? The wave with the most amplitude or the lowest frequency wave?

5. Hearing
What Is the F0 of this wave?
How do you calculate it?

6. Hearing What is the F0 of this wave? How do you calculate it?
What’s “wrong” here?

7. Hearing
Sometimes a combination of waves produces an F0 that is not the lowest frequency wave, but a lower frequency that isn’t an actual component wave.

8. Hearing
Hz tone
They differ by 200 Hz
400 is two times 200

9. Hearing 1400-2800 Hz tone They differ by 1400 Hz
2800 is two times 1400

10. Hearing So, how many Hz do octaves differ in 200 or 1400?
At what frequencies do we perceive smaller differences?

11. Hearing
So, pitch perception doesn’t exactly follow frequency. The mel and bark scales shows when one sound is perceived to be equally distant to another.

12. Hearing

13. Hearing
How do you measure the amplitude of this entire wave if the amplitude is constantly changing?

14. Hearing Do amplitude and volume correspond exactly?
How much louder is the first from the second sound?
They differ by 10 decibels

15. Hearing Source Amplitude In Decibels Times greater than TOH
Threshold of hearing (TOH)
Rustling leaves 10
101
Whisper 20
102
Conversation 60
106
Traffic 70
107
Threshold of pain
130
1013
Military jet
140
1014
Eardrum perforation
160
1016

16. Hearing
So, if you increase amplitude 10 times, how much louder is the sound perceived?

17. Hearing
So, if you increase amplitude 10 times, how much louder is the sound perceived?
Twice as loud

18. Hearing
This is your cochlea. This is cochlea after too much noise.

19. Hearing Which sound is louder? 1, 2, or 3?
The sounds are at 125, 3000, 8000 Hz

20. Hearing Which sound is louder? 1, 2, or 3?
The sounds are at 125, 3000, 8000 Hz
Their amplitude is identical.
What does this say about the resonance curve of the human ear?

21. AntiNoise Antinoise Headphones In cars
Dentist drills, airplanes, snoring, etc.

22. Frequency and Hearing
Human ecolocation