1. The Production of Speech
Vocal folds produce a complex wave (source).
Vocal tract damps some and amplifies others (filter).

2. The Production of Speech
A Fourier analysis of the vowel [ɑ].

3. The Production of Speech
F0 is 100, next peak is at 700 Hz, 2400, 2600 (more or less)

4. The Production of Speech
This is the resonance curve of the vocal tract in /a/ position

5. Relationship between a line spectrum and formants
Paint the peaks in the line spectrum black.

6. Relationship between a line spectrum and formants
Paint the peaks in the line spectrum black, turn the spectrum so that the top edge is pointing toward you. Imagine that the paper isn't a thin thing, but that the edge is wide and the paper is a box. If you could can see through the edge (or side of the box) to the peaks you would see this . . .

7. Each horizontal line is a harmonic of the F0 (Narrow band view)

8. Broadband of the same spectrogram

9. Formant
Formants are groups of harmonics that are amplified by the resonance frequencies of the vocal tract in a particular configuration.
VTDemo

10. Harmonics and Formants
What happens to the harmonics of this vowel as the fundamental frequency goes from low to high? Why? What happens to the formants?

11. Glottal Pulses
What happens to the glottal pulses of this vowel when the fundamental frequency goes from low to high? Why? What happens to the formats?

12. Why don't the formant frequencies change?
The classroom's ceiling will amplify 100Hz sounds regardless of what other frequency sounds you bombard it with.
The resonance frequencies of a system is fixed.

13. How do you change your voice's frequency?

14. How do you change your voice's frequency?
Change the configuration of the vocal folds.

15. How do you change your formants?

16. How do you change your formants?
Change the configuration of the vocal tract.
Changing F0 doesn't change formants. (Video)

17. Source Filter Model

18. Source Filter Model

19. How does the amplitude of the harmonics of an F0 change?

20. How does the amplitude of the harmonics of an F0 change?
The higher the harmonic the lower the amplitude.
Amplitude goes down by 12 decibels each time the frequency is doubled.

21. Why are peaks not equally high in output energy spectrum?

22. Why are peaks at same frequencies in output energy spectrum if they are different in the source spectrum?

23. What is articulatory correlate of F1?
Formants: F1
What is articulatory correlate of F1?

24. What is articulatory correlate of F2?
Formants: F2
What is articulatory correlate of F2?

25. It's all phony
Vocal modification
Formants in electronic music

26. VowelSynth app for iPhone