What is the mucosal wave responsible for?
VF vibration
What are the 2 layers of tissue over the vocalis portion of the thyroarytenoid muscle?
Cover (1st layer)
Transition (2nd layer)
What is the official name of the cover of the vocalis portion of the thyroarytenoid muscle?
Superficial lamina propria = Reinke’s space
What are the two portions of the thyroarytenoid?
Thyromuscularis and the thyrovocalis
How is the mucosal wave formed?
The two layers slide across each other
How does the mucosal wave travel?
Across the superior 2/3 of the VF
The cells become ____ dense as you go deeper into the VF.
more
No mucosal wave will result in what?
Abnormal phonation
What position are the VF in during nonphonatory exhalation?
AB-ducted
When are the VF most widely AD-ducted?
Forced inhalation
When are the VF the longest?
During at rest breathing
When are the VF the shortest?
During the production of low notes (bottom of pitch range).
What are the two glottises of the VF?
Cartilaginous glottis and the muscular glottis
What happens to the VF during whisper phonation?
Only the anterior 2/3 approximate but not firmly; the posterior 1/3 remains AB-ducted, forming the “glottal chink”
Fundamental frequency is related to the _____ and ______ of the vocal folds.
Length and thickness
Short, thick, lax VF will vibrate ______ and have a ______ pitch.
Slower; lower
Long, thin, tense VF will vibrate ______ and have a ______ pitch.
Faster; higher
Vocalizing at higher pitches requires lengthening the VF to do what 3 things?
Reduce mass per unit length
Increase tension
Increase elasticity
What muscles are responsible for lengthening the VF?
Contraction of the cricothyroids and maybe a contraction of the cricopharyngeus
What is required, pressure wise, to increase pitch?
Increasing sub-glottal pressure
How does increasing sub-glottal pressure required to increase pitch create a paradoxical AB-ducting effect?
When we start increasing the amount of air pressure, it AB-ducts the VF. However, for phonation, we want the VF to be AD-ducted! Therefore, it takes more muscular effort to sing at a high pitch to keep the VF together for phonation.
Vocalizing at higher pitches requires what two things?
Increasing medial compression
Increased glottal airflow rate
Vocalizing at lower pitches requires what two things?
Relaxation of the cricothyroids
Simultaneous contraction of the thyroarytenoids
Contraction of the thyroarytenoids causes what to happen to the VF?
Shortens folds
Thickens folds
What is it called when the pitch range is extended beyond the normal stretching of the VF?
Falsetto voice production
What register is our normal talking voice in?
Chest
What is glottal fry?
The opposite of falsetto; it’s when the VF are tightly approximated, so there is a low airflow rate and a low subglottal pressure. Results in a harsh vocal quality.
What is a vocal register?
Pattern of laryngeal and VF adjustments which prevail through a series of pitches. At the limit, VF adjust to a new approximation contour, which results in abrupt changes in vocal quality.
What are the 4 vocal registers?
1) glottal fry or pulse register
2) modal or chest register
3) midvoice register
4) falsetto register
What do vocal registers mean for our evaluation of an individual’s voice?
Someone might be using the wrong vocal register for speech. When you use the wrong register, you’re using abnormal muscular tension. Too much muscular tension can cause strain on the voice and result in a voice disorder.
Changes in tension, length, and approximation of the VF can affect what 3 things?
Frequency, intensity, and quality
What areas are our resonators?
Supraglottal areas
Resonation gives voice what two things?
Quality or timbre
What is acoustic efficiency?
There are certain optimal resonance configurations which result in efficient intensities with full amplifications or harmonics
Higher frequencies are best resonated by _____ degree of pharyngeal tension. Lower frequencies are best resonated by ____ degree of pharyngeal tension.
High; low (more relaxed pharynx)
What is the resonator with the most variability in size and shape?
Oral cavity
Inadequate velopharyngeal closure results in what?
Excessive nasality
A change in the velum position affects what three resonating cavities?
Pharynx, nasal cavity, and oral cavity
What is the site of closure between the nasal cavity and the velum?
Passavant’s Pad
What was the neurochronaxic theory?
The theory that each vibratory cycle of the VF was initiated by a nerve impulse to the vocalis muscle via the recurrent/vagus nerve, and that the frequency of the voice was dependent upon the rate of impulses delivered.
Why was the neurochronaxic theory invalid?
Because the recurrent nerve is longer on the left side than the right side - the VF wouldn’t vibrate synchronously
If the neurochronacix theory were true, patients with tracheotomies would be able to do what?
Phonate… but they can’t! The airstream is required to produce voice.
When was the myoelastic aerodynamic theory introduced?
1843
Define each part: aero, dynamic, myo, and elastic
Aero - air pressure and flow
Dynamic - movement and change
Myo - muscular involvement
Elastic - ability to return to original state
How does the Bernoulli Effect cause AD-duction to occur?
The Bernoulli Effect occurs when the velocity of subglottal pressure increases while approaching and passing through a constricted glottis. The increased velocity creates negative pressure between and just below the medial edge of the vocal folds. The vocal folds are therefore AD-ducted because of the negative pressure.
What is significant about the juncture of the anterior 1/3 and posterior 2/3 of the VF?
The greatest amount of displacement from midline occurs there! It is also, therefore, the greatest point of friction between the two VF. This is why secondary pathologies (nodules, polyps) almost always appear there first!
Why does the posterior portion (cartilagenous portion) of the VF vibrate less?
Because of the weight of the vocal processes in the back