Numerical analysis of effects of transglottal pressure change on fundamental frequency of phonation.
OBJECTIVE
In humans, a decrease in transglottal pressure (Pt) causes an increase in the fundamental frequency of phonation (F0) only at a specific voice pitch within the modal register, the mechanism of which remains unclear.


METHODS
In the present study, numerical analyses were performed to investigate the mechanism of the voice pitch-dependent positive change of F0 due to Pt decrease. The airflow and the airway, including the vocal folds, were modeled in terms of mechanics of fluid and structure.


RESULTS
Simulations of phonation using the numerical model indicated that Pt affects both the average position and the average amplitude magnitude of vocal fold self-excited oscillation in a non-monotonous manner. This effect results in voice pitch-dependent responses of F0 to Pt decreases, including the positive response of F0 as actually observed in humans.


CONCLUSIONS
The findings of the present study highlight the importance of considering self-excited oscillation of the vocal folds in elucidation of the phonation mechanism.
Deguchi
Shinji
S
Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Matsuzaki
Yuji
Y
Ikeda
Tadashige
T
D006801:Humans; D066298:In Vitro Techniques; D008962:Models, Theoretical; D010699:Phonation / Q000502:physiology*; D011312:Pressure; D014827:Vocal Cords / Q000502:physiology*