Phonation* Flashcards
Name the 3 conditions needed for phonation. And what will happen if the conditions are met?
- Flow of air
- Adduction of vocal folds sufficient to build up required subglottal pressure
- Tension to produce stiffness
The vocal folds will then vibration (according to the Aerodynamic-Myoelastic theory.
Explain the Aerodynamic-Myoelastic theory
- At the onset of phonation VF’s are adducted.
- As they close the flow of air produced by expiration is interrupted as it can longer escape through the glottis.
- Caused and increased in pressure, beneath the closed glottis.
- As expiration continues against a closed glottis, subglottal pressure continues to rise, until the VF’s are forced open a little bit.
- This causes a small amount of air to be released through the narrow slit. Meaning subglottal pressure falls.
- Muscular forces adducting the VF’s now exceed the force produced by the subglottal pressure, and the VF’s begin to close.
Aided by Bernoulli Effect.
What are the variants in voicing?
- Frequency = determines pitch,
- Intensity = determine loudness,
- Quality = determines individual characteristics of the voice.
What is frequency?
Perceived pitch is the perceptual correlate of frequency (number of vibrations/second).
The pitch raises as the frequency of vibrations increases.
Longer length of vocal folds = lower pitch.
Pitch is lower in males < females < children.
What are the 3 alterations in pitch determined by? (physical parameters)
- Length = INCREASE = PITCH DECREASE
Decrease = pitch increase - Thickness = INCREASE = PITCH INCREASE
Decrease = pitch decrease - Tension = INCREASE = PITCH DECREASE
Decrease = pitch increase
What are the Thyroarytenoids?
They are muscle-producing changes in length and thickness. Acts to shorten the VF’s. Involved in fine-tuning.
What is Vocalis?
Vocalis is another muscle involved in changing the length and thickness. Acts to shorten and thicken the VF’s.
What could be classed as vocal misuse?
- Raising voice if working in a loud environment.
This causes a strong adduction causing trauma to vocal folds.
What are the organic diseases?
Fluid retention and oedema in whole body.
Fluid build up in vocal folds meaning pitch lowers.