Hearing & Deafness (5)
Timbre, Music & Speech
Vocal Tract
Source & Filter
Larynx Vocal tract Output sound
Pitch and Formants1. Harmonics (giving pitch) produced by vocal cord vibration
frequency125 Hz (fundamental)
FormantsF1 = 396HzF2 = 1520Hz
F3 = 1940Hz
2. Formant frequencies: resonances of the vocal tract3. Formant frequencies change as you change the
shape of your vocal tract
Vowel production
Tuvan throat music
Tuvan throat music - 2
Vocal tract change
Me (m)
Higher pitch Shorter vocal-tract(higher formants)
Both (-> f)
narrow-band spectrogram
sine-wave speech
SWS
Adding harmonics to make an instrument’s timbre
Track 53
Different notes on clarinet and oboe
What determines an instrument’s timbre
1. “formant” frequencies
2. Amplitude envelope
3. Onset / offset transients
Instrument timbre does not scale - it is more like speech formants
Timbre does NOT stay constant when
sounds are simply scaled up in frequency
frequency ->
dB
Timbre stays more constant when the
formants stay constant
frequency ->
dB
frequency ->
dB
maximum amplitude
maximum amplitude
maximum amplitude
Cheap synthesisers do this to generate different notes
Natural instruments and good synthesisers do this
Bassoon & violin notes
Track 57
Forwards & backwards temporal envelopesTrack 54
Track 56
Time (s)0 0.891633
–0.1693
0.1385
0
Time (s)0 0.891633
–0.1693
0.1385
0
Onset transients
Time (s)0 0.0842
ミ 0.6922
0.7817
0
Time (s)0 0.0842
ミ 0.6922
0.7817
0
Why are some intervals consonant and others dissonant?
Consonant musical intervals form simple ratios
octave 2/1 fifth 3/2fourth 4/3 major third 5/4minor sixth 8/5minor third 6/5major sixth 5/3 major second 9/8
consonant
dissonant
Two complex tones separated by a perfect fifth (3:2)
Separate Excitation Patterns
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0 500 1000 1500 2000 2500 3000frequency
One
Two
Total Excitation Pattern
0.0
5.0
10.0
15.0
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25.0
0 500 1000 1500 2000 2500 3000frequency
Consonant intervals havemaximally separated component frequencies