Deguchi Shinji, Matsuzaki Yuji, Ikeda Tadashige
Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Ann Otol Rhinol Laryngol. 2007 Feb;116(2):128-34. doi: 10.1177/000348940711600209.
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.
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.
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.
The findings of the present study highlight the importance of considering self-excited oscillation of the vocal folds in elucidation of the phonation mechanism.
在人类中，经声门压力（Pt）降低仅在模态发声范围内的特定嗓音音高时才会导致发声基频（F0）升高，其机制尚不清楚。
在本研究中，进行了数值分析，以研究由于Pt降低导致的F0的嗓音音高依赖性正向变化的机制。根据流体和结构力学对气流和气道（包括声带）进行了建模。
使用数值模型进行的发声模拟表明，Pt以非单调方式影响声带自激振荡的平均位置和平均振幅大小。这种效应导致F0对Pt降低的嗓音音高依赖性反应，包括在人类中实际观察到的F0的正向反应。
本研究结果突出了在阐明发声机制时考虑声带自激振荡的重要性。
