Physics 1251 The Science and Technology of Musical Sound

1
Physics 1251The Science and Technology of
Musical Sound

• Unit 3
• Session 32 MWF
• The Singing Voice

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Foolscap Quiz
• What produces the vibrations in the human voice?

The vocal folds produce the vibrations required
for phonation of the human voice.
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• A Little QA

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Singing Voice

What is the difference?
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• 1' Lecture
• The pitch range of the singing voice is
  determined by the properties of the vocal folds.
• The intelligibility of words is due to the
  relationship of the first two formants.
• Modification of the shape of the vocal tract
  significantly affects the timbre of the singing
  voice.

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Vocal Apparatus

• Nasal cavity
• 23. Pharynx
• 4. Vocal folds
• 5. Tongue
• 8. Epiglottis
• 9. False v.c.
• 10. Trachea

The Vocal Tract is the organ of speech and the
instrument of the Voice.
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Mechanics of the Vocal Folds
• 80/20The properties of the vocal folds determine
  their vibration frequency.

Larynx
Larynx
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Mechanics of the Vocal Folds
• 80/20The properties of the vocal folds determine
  their vibration frequency.

Vocal Folds
Larynx
fvocal 1/2p vk/ m
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Mechanics of the Vocal Folds
• 80/20The properties of the vocal folds determine
  their vibration frequency.

fvocal 1/2p vk/ m
Vocal Folds
Density ?
k fold stiffness m effective mass
For a cord f 1/2LvT/ µ T s (t?d)
µ ?(t?d) f
1/2Lv s / ?
Stress s
Length L
fvocal 1/2p vk/ m
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Mechanics of the Vocal Folds
• 80/20The properties of the vocal folds determine
  their vibration frequency.

fvocal 1/2p vk/ m
f v s / (4L2 ?)
k fold stiffness m effective mass
k p2 s m/ L2 ? p2 T/ L m ? L(t?d)
For a cord f (1/2L)vT/ µ T s
(t?d) µ ?(t?d)
f (1/2L)v s / ?
L 0.017 m ? 1040 kg/m3
s 12 kPa
f 100 Hz m 200 mg T
0.14 N
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• The Mechanics of the Vocal Folds
• 80/20The properties of the vocal folds determine
  their vibration frequency.

f1 (1/2L)v s / ?

• 80/20Conclusions
• Resting length, stress and density set voice
  range
• Stress (tension) can be increased external to
  the vocal fold or internal to it.
• Overall, increased tension increases stiffness,
  pitch

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Vocal Range Fundamental Pitch

1175 Hz
880 Hz
587 Hz
523 Hz
392 Hz
329 Hz
196 Hz
165 Hz
147 Hz
131 Hz
98 Hz
82 Hz
Tenor C2 C5
SopranoG3 D6
Mezzo-SopranoE3 A5
?
?
Baritone G2 G4
Bass E2 E4
ContraltoD3 D5
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Anatomy of the Human Voice
• 80/20During adolescent the vocal folds grow
  longer and the voice lowers in pitch.

Vocal Folds lengthen at puberty
f1 v s / (4L2 ?) f1 1700/L (mm) Pitch lowers
at puberty.
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Anatomy of the Human Voice
• 80/20The vocal folds comprise muscle, lamina
  propria and epithelium.

Cover
Body
Epithelium
Lamina Propria (3 layers)
Thyroarytenoid Muscle
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Video of
• Laryngoscopy
• Tenor, Baritone and Soprano

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• 80/20Pitch is raised by increasing tension on
  vocal folds, both external to the vocal fold
  (Cricothyroid muscle) and internal to it
  (Thyroarytenoid muscle).
• f1 (1/2L)v s / ?

The nature of the stress in the vocal fold
(internal or external tension) permits phonation
in different registers.
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• 80/20Vocal Registers
• f1 (1/2L)v s / ?
• s sexternal sinternal

Terminology Speaking Pulse Modal Falsetto Singi
ng Chest Head Falsetto (alternative) Fry Middl
e Whistle Stohbass flageolet
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• 80/20The shape of the Vocal Tract determines the
  frequency of the Formants.www.exploratorium.edu/ex
  hibits/vocal_vowels/vocal_vowels.html

ah
eh
oh
oo
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Spectrogram of Human Speech

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Speech
• 80/20The individual units of speech are called
  phonemes.
• The classes of (English) phonemes are
• Unvoiced Plosives? p, t, k (c, q, x)
• Voiced Plosives? b, d, g
• Fricatives? unvoiced/voiced f/v, th/th,
• Sibilants? unvoiced/voiced s(c)/z, sh/zh (j),
  h/kh
• Liquids? l, r
• Nasals? m, n, ng
• Semi-vowels? w, y
• Vowels? a, e, i, o, u

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Vowels and Formants
• 80/20The relative frequency of the 1 st and 2 nd
  vowels formants are unique to various vowels.

i
I
e
æ
e
Second formant frequency
?
D
U
u
c
First formant frequency
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Control of Formants
• 80/20Tongue and lip placement and the shape of
  the pharanx are most important in vowel formation.

Corner Vowels
D
i
u
A
A
A
f
f
f
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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Formants and Singing

Harmonics align with Formants
Singers Formant

• Vowel modification shifts formats.
  Alignment of formants with harmonics
  intensifies pitch.
  Dilation of vocal tract causes
  Singers Formant.

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Physics 1251 Unit 3 Session 32 The Singing
Voice

• Summary
• The pitch range of the singing voice is
  determined by the size, tension, and density of
  the vocal folds.
• Vocal registers and breaks in the voice result
  from changing modes of oscillation of the vocal
  folds.
• Vowels are distinguished by the frequency
  relationship of the first two formants.
• Modification of the vocal tract shape sets the
  timbre of the singing voice.