ENT meeting workshop

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ENT meeting / workshop
Voice Quality Systems

• Odense
• Friday 6th October 2006.
• Interpretation
• Peter Pabon
• Voice Quality Systems
• Alphatron Medical Systems BV
• KEBO MED

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Interpretation speech area
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With louder phonation the voice follows an upward
trace
Physiological ideal trace
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Mechanism
Physiological principle the sound level
increases with the fundamental frequency and vice
versa.

• A larger vocal fold vibration amplitude also
  means a larger average tension in the vibrating
  vocal folds and thus a higher pitch (passive).
• More tension needed to compensate larger forces
  from higher air pressure (active).

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A comparable mechanism controls the shape in the
phonetogram of

• Bottom contour/threshold of phonation
• Upper contour, max. phonation level
• Register boundaries

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Maximum shifts with louder spreech along a
parallel trajectory
Calling voice?
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Models / objective parameters,what is normal for
a speaking voice?

• Helbert Damstés rule of thumb, centre first
  octave (6 semitones from lowest pitch).
• Peter Pabon 70 dB with normal/soft phonation
  (many handbooks specify 80 dB)
• Rosemary Orr
• Renée Speyer (dec.03) speech position is point
  of reference, no numerical data.
• Adrian Fourcin (fundamental frequency) movement
  pattern for a given text is vary variable in
  between individuals, but very reproducible within
  individuals (pers. comm).

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Interpretation shapeand contour
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Reproducability contour measurement higher with
max ( 3 dB). then with min (3..6 dB).
The line is also smoother, more straight, does
not improve with longer integration times, no
shifts or up and down dancing during recording.
More uncertain, jagged, more difficult to set
one value, instable but not less important!
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Typical shape parameters
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Which contour / shape parameters are important?

• Minimum SPL (Heylen, Speyer, Wuyts-DSI, and many
  others).
• Parameters that rate the phonetogram contour
  around the speech area (Orr, Speyer, Heylen)
• Highest tone, tone range, Intensity range
  (Heylen, normal versus group noduli to test
  relevance)
• Sloping bottom contour (Heylen, noduli) Soft and
  high in falsetto, the first area that is
  sacrificed, high jitter

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Speyer, multidimensional analysis to factors that
rate therapy effects finds two factors

• Changes in lowest frequency and the area under
  the mean speaking fundamental.
• Changes in minimal intensity together with size
  of speech area

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Comment authors

• Logopeds that cooperated were focussed on
  improvement of the speaking voice. This could
  explain why the largest changes were found in the
  speech area.
• remark speech therapy works!

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Shape changes with pathologies

• In general voice pathology will lead to a
  reduction of the tonal range and the dynamic
  range, a decrease of the total area.
• De contour gets more jagged, with sharp edges up
  and down. Large holes start to show, sometimes
  the phonetogram breaks up in pieces, islands of
  sustained vibration. This makes it more difficult
  to apply general shape parameters in case of
  pathologies.

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As multiple factors effect the shape, it is
impossible to link one specific shape (change) to
one specific pathology or type of vocal use /
abuse.

• The voice as a musical instrument The more
  physical differences occur (for instance due to
  pathologies), the more different the control
  settings and the more different the resulting
  phonetogram shape.
• Speyer (dec. 2003) The effect of voice therapy
  on the VRP is multidimensional, many different
  changes in VRP are possible