ENT meeting workshop

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ENT meeting / workshop
Voice Quality Systems

• Odense
• Friday 6th October 2006.
• Voice registers in the phonetogram
• Peter Pabon
• Voice Quality Systems
• Alphatron Medical Systems BV
• KEBO MED

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Voice quality information in the phonetogram
remarks

• Registers and internal boundaries can be
  localised by two features
• The displayed voice quality parameter (crest
  factor).
• The trace that the cursor shows in the visual
  feedback while singing.
• Implicit / hidden but very strict practical rule
  
• The voice sticks to the vibrational mode
  (register) it is in, once started, the voice
  tends to keep the register chosen at voice onset,
  and can only be pushed to another vibrational
  mode in an abrupt transition. Singing very soft
  works fine to conseal such a transition.
• There is an overlap area between the two
  registers.
• Covering this area using two different register
  qualities can blurr the recorded quality in the
  transition zone.

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• Register definition according to Garcia
  (1805-1906), singer and inventor of the
  laryngoscope
• A series of succcessive tones of equal quality
  sung in a tone scale from low to high and
  produced by application of the same mechanical
  principle. The nature of this series differs from
  another series of successive tones of equal
  quality but produced according to another
  mechanical principle."

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two vibration mechanisms

• Low Modal (also called chest voice).
• High Falsetto (also called head voice)

two extra vibration mechanisms

• Very low Pulse/ vocal Fry
• Very high Whistle register

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Pulse register / vocal fry

• Less then 50 vibrations per second
• Irregular vibration
• Long closed phase

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Pulse register / Vocal Fry
Sound Level (dB SPL)
Pitch / Fundamental Frequency (Hz)
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Visualizing Vocal fry / Pulse register

• Normally not recorded in the phonetogram.
• Too irregular vibration, too much jitter.
• Is kept out by jitter threshold.
• You can adjust this threshold and allow pulses
  noise to be recorded.
• Choose main menu option ControlsJitter treshold

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Jitter threshold
Normal (record everything below 5 variation in
fundamental frequency)
Threshold value raised to15, much more
irregularity (jitter) allowed.
No threshold anymore, every sound produces a
spot .
Threshold elevated, only very regular and
constant fundamentals are recorded.
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When to adjust the jitter threshold?

• To record a phonetogram with very bad voices like
  laryngectomies.
• With extreme vibrato or fast glides yells
  (alternative in analyzer adjustments).
• To trace additional noise sources that are
  suppressed but still interfere.

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Modal register
SoundPressure Level (dB SPL)
Fundamental Frequency (Fo) in Hz
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Falsetto register
SoundPressure Level (dB SPL)
Fundamental Frequency (Fo) in Hz
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Register overlap
SoundPressure Level (dB SPL)
Fundamental Frequency (Fo) in Hz
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Route planningdifferent maximums, different
register, same Fo

• Optimal starting point
• For reaching the high end of modal register.
• For reaching maximum level in falsetto/head.

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End part III, registers
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The Dip in the upper contour

• Simplest evidence of a two-register system
• The transition between modal and falsetto
  register varies with Fo and SPL
• A clear visual dip does not mean abrupt
  dynamical transitions
• Can be visually missing but dynamically apparent
  !
• Can be masked by mixing (a singing technique to
  blend the two registers)

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What is there to learn?

• There is an overlap region/area.
• A comparable overlap area could be defined by
  making separate recordings for the two registers.
• The higher and louder you sing the more narrow
  the overlap area (and the steeper the
  transition between the two registers)
• Above the point where the two lines cross you may
  find the dip

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Lines that end in the dip (sketch)
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Pushing modal register upward

• Dangerous area for most of us.
• Explored only by starting at a somewhat lower
  frequency but loud in modal register.
• Getting there in a controlled way starting from
  falsetto register is against physiology.
• Modal register pushed upward.
• Belting
• Cut-off in a tone-copying protocol

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Locking to a mode
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Dynamically

• Starting point / settings could look almost the
  same.
• Quality and position in the phonetogram at the
  end of the phonation can differ largely.
• Onset point /setting can sustain its effect over
  a long period of time.
• Hysteresis effect.
• Comparable mechanism at the phonation threshold.

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Singing soft and high

• Is often the most difficult task for the voice
• Dynamics at the top of the higher (falsetto)
  register is often the thing to have.
• The higher register is often the first to
  collapse dynamically with pathologies.

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Pathologies and voice patients

• The healthy voice shows a large variety in range,
  qualities, register settings etc. There are two
  main vibration mechanisms.
• The vibration mechanism of the pathological voice
  operates far from the ideal, and is therefore
  brought to settings, ranges and qualities that
  are more complex, more vulnerable, more time
  variable, and less comparable than the normal
  case.

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Mixing
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Mixing

• Singing technique to smoothen the voice quality
  and the level over the pitch range.
• How to sing? I dont know.
• What do you see in the phonetogram -Smooth
  quality change -No dip -More power in falsetto
  register at lower Fo -Pushing up of modal
  register is avoided -Starting loud in
  modal/chest is avoided
• It is a technique that can be completely
  incorporated

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Typical example of mixing
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You can also avoid Modal Register
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Jitter (top) / Crest Factor (bottom) together