phys 103 lecture 29 voice acoustics. vocal anatomy air flow through vocal folds produces...
TRANSCRIPT
Vocal anatomy
Air flow through vocal folds produces “buzzing” (like lips)
Frequency is determined by• thickness (mass) men have lower pitch• muscle control (stiffness)
Vocal tract acts as a resonator• length is fixed (15-20 cm)
Vocal Spectrum
Sound entering the trachea is close to a pulse train ( many harmonics of nearly equal amplitude)
Similar to organ reed: frequency of vocal folds is not much susceptible to feedback (vocal tract resonances) – it is determined mainly by muscular control
How we get vowels
Recall: 1. timbre of sound depends on the relative amplitude of harmonics2. pitch depends on the frequency of the fundamental
Resonance frequencies of vocal tract shape the spectrum -> determine timbre
Different vowels (same pitch) are essentially different timbres
We control the frequencies of formants by changing the shape of the vocal tract
Resonance frequencies of the vocal tract are called formants
First formant typically controlled by mouth opening
Second formant typically controlled by tongue position