Nasalance Nasalization

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Nasalance/ Nasalization

• 3/7/00

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Velopharyngeal Function

• Nasality nasal emission of air are symptoms of
  many speech disorders
• Cleft palate, dysarthria, dyspraxia,hearing
  impaired
• Nasalization is the existence of significant
  communication between the nasal cavity and the
  rest of the vocal tract

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Velopharyngeal Function

• Inappropriate nasalization-
• Causes, 1) Nasal emission (abnormal escape of air
  via the nose) 2) Nasality (Hypernasality)-
  unacceptable voice quality that results from
  inappropriate addition of the nasal resonance to
  the vocal tract
• Nasality does not involve large nasal airflows or
  change intraoral air pressure like nasal emission

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Nasality

• Reliably perceived
• Perceptual attribute- requires judgement of a
  listener
• Mostly a function of velopharyngeal port opening
  size
• Vowels have different levels of nasality (low
  vowels-high nasality High vowels- low nasality)
• So, dont use an isolated vowel to judge nasality

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Testing Decisions

• Difficulty in determining differences between
  velar and pharyngeal function
• No linear relationship between size of
  velopharyngeal opening and level of nasality
• Nonspeech tasks are poor indicators of VP
  function- sucking and impounding intraoral air
  pressure can be accomplished by linguapalatal
  valving

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Testing Decisions

• Nonspeech functions cont.-Cleft palate patients
  who cant achieve VP closure during speech,
  routinely do during swallowing
• Measurement of static tasks (i.e. sustained
  vowels) differ from speaking tasks- timing is not
  being tested

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Instrumentation- VP

• Electromyography- not suitable for clinical use
• X-Ray techniques- visualization of palatal
  activity
• Sound Spectrography
• Airflow measures

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Ideal Measurement Criteria

• Noninvasive
• Assess VP function during speech
• Nondisruptive of respiratory, ventilatory or
  articulatory function
• Excellent correlation with perceived nasality
• Low cost
• Ease of interpretation

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Visualization of Palatal Structures

• Endoscopy- telescopic device to visualize velar
  function
• Oral Panendoscope
• Disadvantages
• Gagging
• Articulation is compromised
• Fiberoptic Endoscope
• Viewing of VP from above
• More invasive than panendoscope

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Indirect Assessment Methods

• Articulation tests
• Distortion on high pressure consonants for
  inadequate closing
• Distortion on nasal sound for inadequate opening
• IPAT (Iowa pressure articulation test)
• Disadvantages-
• Articulation problems may not be due to VPI

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Indirect Assessment Methods

• TONAR (oral nasal acoustic ratio) Nasometer
• Two microphones (nasal and oral)
• Nasal and oral amplitude
• Ratio of nasal to oral output nasalance
• Nasalance has been found to correlate moderately
  with perceived nasality

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Laboratory

• Nasometer-
• Nasal sound pressure/oral sound pressure
  nasalance
• 0-100 Nasality- more nasal airflow the higher
  the ratio becomes
• Part I-
• Record amount of nasalance for /m/
• Normal?
• What might give you low nasalance?

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Laboratory

• Part I cont.-
• Record amount of nasalance for /a/
• Normal?
• What might give you high nasalance?
• Measure nasalance from figure A for /m/ and /a/
  and compare to your measures.
• Now, produce /æ/, /i/ and /u/ in time history
  display- describe differences in mean nasalance
• Why might mean nasalance differ between vowels?

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Laboratory

• Part II- Use Nasometer!
• Repeat /ma/ syllable at moderate rate
• Mark the vowels and consonants
• Mean and SD nasalance for the whole sample
• Mean nasalance for vowel and for consonant
• How do they compare to the isolated production of
  /m/ and /a/ earlier?

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Laboratory

• Part II- Use Figure B
• Resonance disorder (hyper or hyponasality)
  repeated sample of /ma/ syllable at comfortable
  rate
• Compare to previous sample of syllable train
• Mean and SD nasalance for entire sample
• Mean of vowel and consonant productions
• Compare to previous speaker
• Consistent of variable nasalance record compared
  to other speaker

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Laboratory

• Part II- Use Nasometer!
• Normal speaker repeating /ba/ syllable at
  comfortable rate
• Mark each vowel and consonant
• Mean and SD nasalance for entire sample
• Mean of vowel and consonant productions
• Compare to previous speaker
• Why might you see different vowel nasalance when
  compared to /ma/

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Laboratory

• Part II- Use Nasometer!!
• Normal speaker mean nasalance for sentences
• Mama made some lemon jam
• Please put the five cupcakes back
• Use Figure C Take same two sentences and repeat
  by a person with a resonance disorder
• Assess differences between patients

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Laboratory

• Part II- Use Figure D
• Locate each phone
• /aI/, /t/, /aI/, /dð/ /e/, /b/, /eI/, /I/
• Regions of nasal flow
• Fill in table of nasal flow during each phone
• From the record what is the relationship of nasal
  flow during high Pio?

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Laboratory

• Part II- Use Figure E
• Use sample- I tend the mail
• Mark each phone
• Areas of significant flow
• Measure nasal flow and Pio during each phone
• Is nasalization limited to the nasal phones /n/
  /m/?
• Why might their be hypernasality in the normal
  speaker?

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Laboratory

• Part III- Use Figure F
• Velopharyngeal timing
• Relationship between nasal flow Pio-describe
  this childs VP function