Phonation Flashcards
list the five steps between the first step where VFs abducting via PCA muscles (during inhalation), to the last step where the mucosal wave is produced
- VFs adduct via LCA, IA, and TA muscles 3. Ps builds beneath the VFs 4. Ps overcomes closed VFs and the folds are blown open 5. VFs open: bottom to top 6. as top of VFs begin to open, bottom of VFs begin to close (aka vertical phase difference)
principals of bernoulli effect (3)
when glass / liquid flows through a constricted passage, velocity increases while outward pressure of their molecules decreases; pressure drop is perpendicular to direction of the flow; if the walls are pliable, decrease in outward pressure moves the walls toward each other
bernoulli effect and VFs (4)
- Ps forces VFs apart 2. velocity increases 3. pressure between VFs decreases 4. VF walls (glottis) comes together along with natural VF elastic recoil
myoelastic : ___ :: aerodynamic : ___
laryngeal muscle activity occurring during phonation and its effect on VF elasticity; aerodynamic determinants on VF vibratory cycle (opening / closed phases)
myoelastic aerodynamic theory is based on two forces: ___ (2)
subglottal pressure (Ps); negative pressure due to bernoulli effect
re: determinants of VF vibration
opening phase : build up of Ps :: closing phase : elasticity, mass of VFs, and bernoulli effect (negative pressure between VFs) - which bring the VFs back to midline
aerodynamic
vocal tract inertance (3)
VF vibration is assisted in BOTH directions (opening and closing) by changes in Ps; the build up and release of Ps is delayed in respect to VF opening and closing, creating vocal tract inertance; vocal tract driving force (pressure and flow) and vocal tract tissue velocity (opening and closing of VFs) are asymmetrical - this helps us maintain self-sustained vibration
cover model : ___ :: body-cover model : ___
explains effect of cricothyroid and thyroarytenoid muscle activity on the tension-stress of the VF cover; explains effect of thyroarytenoid muscle on frequency (increase or decrease depending on VF depth and vibration), also level of activity in cricothyroid muscle
in the cover model, when the cricothyroid contracts, VF cover tension increases so frequency increases; when the thyroarytenoid contracts, ___
the VF tension decreases (becomes loose) so the frequency decreases
cover model : only the ___ is in vibration :: body-cover model : the ___ (2) are in vibration
cover; body and cover
body-cover model contingency
if thyroarytenoid contracts at high frequency (loud phonation), VF tension-stress increases so frequency increases AS LONG AS cricothyroid activity is not at its maximum; if cricothyroid activity is at its maximum, thyroarytenoid loses stiffness, so frequency decreases
relationship between sub glottal pressure and frequency
when Ps increases, intensity increases, so frequency increases
dynamic strain
occurs when increased amplitude of vibration causes the VFs to lengthen, increasing tension and increasing frequency
in dynamic strain, ___ result in increased pitch
longer fibers
glottal configurations in nonlinear tissue movement (2)
convergent glottis; divergent glottis
convergent glottis : ___ :: divergent glottis : ___
VFs opening bottom to top, transglottal pressure is positive, net tissue velocity is outward, and air molecules converge; VFs closing bottom to top, transglottal pressure is negative, net tissue velocity is inward, and air molecules diverge
in nonuniform tissue movement, energy is transferred from the air stream to the VF tissue because ___
the net driving force (pressure) over the vibratory cycle is synchronized with the VF tissue movement
what is the essential feature of self-sustained oscillation?
asymmetry (opening phase is different than closing phase)
