Vocal Registers

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Vocal Registers

• Physiological and acoustic correlates
• of voice quality in singing

Carrie Niziolek carrien 6.541 18 may 2006
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Voicing

• Voicing occurs when laryngeal muscles adduct the
  vocal folds and airflow from the lungs causes
  them to vibrate.
• Length and tension changes in the vocal folds
  determine the frequency of vocal fold vibration,
  which in turn determines the F0 (perceived pitch)
  of the voice.

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Vocal registers

• Registers perceptually distinct regions of vocal
  quality that can be maintained over some ranges
  of pitch and loudness
• Singers can change timbre (spectral quality)
  while keeping pitch constant
• Pulse register (glottal fry)
• Modal register (chest voice)
• Head register
• Falsetto

formula for pitch(analogy to string instruments)
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Register breaks

• i, head ? chest voice

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Register breaks in pop music
Flicks written by I. Heap, G. Sigsworth (Frou
Frou)
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Laryngeal muscles

• Cricothyroid
• Lengthens (tenses) vocal folds
• Thyroarytenoid
• Adducts, shortens (relaxes) vocal folds

CT
TA
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Laryngeal muscles, cont.
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Laryngeal muscles, cont.

• Cricothyroid dominates
• Folds lengthened, thinned, and stretched (higher
  pitch range)
• Only outer layers (SLP) vibrate
• Large OQ less than 50 closure
• Almost all energy in F0
• Thyroarytenoid dominates
• Folds shortened (lower pitch range)
• Large amount of vocal tissue in vibration
• Smaller OQ more than 50 closure
• Energy spreads to higher harmonics

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Hypothesis

• CT dominance
• disproportionate vibration at top of vocal folds
  (higher TL)
• reduction of high harmonics
• perception of lighter, thinner voice quality
• TA dominance
• increased amplitude of vibration at bottom of
  vocal folds (lower TL)
• glottal flow to reduce to zero more steeply and
  more rapidly (lower OQ)
• perception of fuller, richer voice quality

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Methods

• Subjects two female singers (one classically
  trained)
• Tokens a e i o u sung at three pitches
• A5 (440 Hz)
• D4 (300 Hz)
• D5 (600 Hz)
• Measure H1-A3 at the middle of the vowel
  interpret as degree of spectral tilt

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Acoustic analysis u
head voice TL 48.7
chest voice TL 16
trained voice TL 40.5
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Acoustic analysis u
head voice
chest voice
trained voice
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Acoustic analysis a
head voice TL 28.2
chest voice TL 11.3
trained voice TL 19.1
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Acoustic analysis a
head voice
chest voice
trained voice
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Acoustic analysis A440
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Acoustic analysis D300, D600
low D
high D
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Acoustic analysis D300, D600
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Acoustic analysis across pitches
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Conclusions

• Trained voice exhibits the ability to blend chest
  and head registers (evident both spectrally and
  perceptibly).
• Training helps strengthen both CT and TA muscles,
  allowing for strong opposition and simultaneous
  tensing of muscle and vocal ligament.
• Training also enhances the ability to activate
  adjacent muscles selectively and in a graded
  manner.
• You dont need smooth register changes to be a
  pop singer.

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Future work

• Male singers
• Electromyogram studies to more precisely map the
  contribution of laryngeal muscles
• Modeling of glottal source and resonant effects

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Shameless plug
Resonance spring concerttomorrow (Friday, May
19th)9 p.m., 10-250
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References
Brown WS, Hunt E, and Williams WN, 1988.
Physiological differences between the trained and
untrained singing and speaking voice. Journal of
Voice 2(2)102-110. Shipp T and Izdebski I,
1975. Vocal Frequency and Vertical Larynx
Positioning by Singers and Nonsingers. Journal
of the Acoustical Society of America
58(5)1104-1106.   Titze IR, 1998. Five
Ingredients of a Physiologically Gifted Voice.
Journal of Singing, January 1998.   Titze IR,
1994. Principles of Voice Production. New
Jersey Prentice Hall. Titze IR and Sundberg J,
1992. Vocal Intensity in Speakers and Singers.
Journal of the Acoustical Society of America
91(4)2936-2946.