Myoelastic Aerodynamic Theory and Vocal Rehabilitation (part 1)

What is the Myoelastic Aerodynamic Theory of Vocal Fold Vibration?

Explains how steady stream of air from lungs sets vocal folds (mostly the cover) into vibration

Myoelastic Aerodynamic Theory of Vocal Fold vibration paragraph:

The myoelastic aerodynamic theory is responsible for explaining the elastic recoil that pulls the vocal folds together, and blows them apart. Before phonation, the vocal folds are adducted. As subglottal pressure increases, the vocal folds are forced open, and air rushes through the glottis. As the air flows over the curved edge of the vocal fold, the elastic recoil of our muscles takes over, and causes the vocal folds to snap back together and briefly pause the airstream. This process is called the Bernoulli effect. The opening and closing is repeated and the perception is vocal fold vibration.

Describe Chant Talk:

- Cross between singing and speaking - Maintain steady subglottic pressure - Reduces variability and promotes easy onsets - Increase vibration in mask of face

Describe easy onset:

- Decreases vocal fold adduction at start of a word - Start with /h/ - Optimal adduction: vocal processes barely touching

Describe confidential voice:

- Holistic approach to help pitch, loudness, and variability - Decreases vocal fold adduction - Patient uses a breathy voice; short term solution

Describe Hum and Nasal Consonants:

- Hum requires steady airflow - Vocal fold adduction reduced during production of these sounds compared to other sounds

Describe trill:

- Lip or tongue trill; with and without phonation - Used for post-op scarring - Increase levels of airflow and air pressure - Gets respiratory system going, decreases vocal fold adduction needed to allow airflow through

What is normal voice?

- Normal depends on cultural, environmental, and individual factors - Voice is constantly changing--> development, sickness, emotion

Describe REST:

- Range Expansion Stabilization Technique - Physical therapy for the voice - Pitch glides and swell tones (same pitch, vary intensity) - Maximum sustained phonation

Describe SOVT

- Semi Occlusion of the Vocal Tract - Requires high airflow and adjustment of vocal tract shape and constriction points - Formant tuning (keep F0 and harmonics 2 and 3 near or below 1st formant, F1)

Describe yawn/sigh:

- Stimulate or trigger a real yawn with sigh at end - Adjust muscle tension (increase some muscles, decrease tension in other muscles) - This changes shape of vocal tract, lowers/relaxes larynx, and increases size of pharynx

What is the goal of voice therapy?

- To restore the best voice possible - Voice is functional for employment and general communication

Describe Chewing:

- Vegetative movement with phonation - Foster easy onset of phonation without specifically addressing it - Reduces tension in laryngeal and articulatory muscles

Describe order of events in Myoelastic Theory (7 things)

1. Approximate vocal folds (adduction) 2. Air pressure builds up beneath vocal folds 3. Air pressure pushes membranous folds apart 4. Vocal fold tissue moves laterally until force of tissue elasticity is greater than air pressure 5. Vocal folds then move medially 6. As vocal folds come together there is Bernoulli effect 7. Cycle starts over

What are 2 components of voice therapy?

1. Patient education and modification of voice use 2. Voice conservation and improved vocal hygiene

What 8 factors should be considered when determining prognosis?

1. Patient recognizes that there is a problem 2. Patient is willing to follow a therapy plan 3. Willingness to change vocal habits 4. Interference with psychiatric problems 5. Voice disorder must be able to be changed by voice therapy 6. Patient has appropriate expectations 7. Consider patient's laryngeal condition and health status 8. SLP's ability to relate to patient