View
18
Download
0
Category
Tags:
Preview:
DESCRIPTION
Please be Seated. The physics of sound: What makes musical tones different?. Special Lecture for the 2005 Year of Physics in coordination with the French National Center for Scientific Research and the French Embassy in Washington DC. Special Guests: - PowerPoint PPT Presentation
Citation preview
The physics of sound:What makes musical
tones different?
Special Lecture for the 2005 Year of Physicsin coordination with the
French National Center for Scientific Researchand the
French Embassy in Washington DC
Special Guests:
Michẻla Castellengo, Research Director, Musical Acoustics Lab, University of ParisHugues Genevoire, Research Engineer, Musical Acoustics Lab, University of ParisCharles Besnainous, Research Engineer, Musical Acoustics Lab, University of ParisJoseph Curtin, stringed instrument makerBenoît Rolland, bow makerSerge de Laubier, musician-researcher
Standard electronic wave forms
• Sine wave
• Sawtooth wave
• Pulse train
• Triangular wave
• Square wave
Fourier’s Theorem:Any complex wave can be“synthesized” by adding itsharmonics together with the
proper amplitudes and phases.
“Fourier synthesis” and “Fourier analysis”
Factors in Tone Quality1. Amplitudes of harmonics
2. Attack and decay transients
3. Inharmonicities
4. Formants
5. Vibrato
6. Chorus effect
Origin of Vocal Formants(~17.5 cm closed tube)
Frequency:
f1 = 500 Hz
f3 = 1500 Hz
f5 = 2500 Hz
Vocal range:
150-850 Hz
500-2500 Hz
1500-3500 Hz
Mode:
TheSingersFormant
Averaged spectral energy distribution:Light: ordinary speechDark: orchestral accompanimentBrown: Good singer with orchestra
Johan Sundberg: The Acoustics of the Singing Voice; Sci. Amer., March 1977
Helium Voice
Singing frequency remains the same
(vibration of vocal folds)
Formant frequencies rise because
She >> Sair
Why?
Recommended