Objective This investigation addressed the desirable source–airway interaction obtained with vocalization through a semi-occlusion at the mouth. The semi-occlusion was a flow-resistant tube of varying length and diameter. Method The methodology was strictly computational. Airway shapes resembling those obtained from magnetic resonance or computed tomography imaging were stylized. Supraglottal and subglottal acoustic impedances were calculated, from which inertagrams were plotted over a frequency range of 0–4000 Hz. The inertagrams predict which harmonics are likely to be strengthened. Results The combination of epilaryngeal airway narrowing and lengthening, a pharyngeal expansion, and an oral narrowing behind the tube produce the best overall inertagram for pitch glide exercises. This configuration supports harmonics of the source evenly over a range of 300–4000 Hz. Conclusions For clinical applications, theory predicts that the length of a tube or straw does not matter if the inner diameter is on the order of 3 mm or less. For wider open-ended tubes, greater length can compensate for the wider diameter for the beneficial inertance effect, but the desired steady pressure in the airways for vocal fold posturing cannot be maintained.

中文翻译：

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各种半闭塞声带的惯性图

客观的这项研究解决了通过口腔半闭塞发声所获得的理想的声源-气道相互作用。半闭塞管是不同长度和直径的阻流管。 方法该方法是严格计算的。气道形状类似于从磁共振或计算机断层扫描成像中获得的气道形状，并且被程式化。计算声门上和声门下声阻抗，并根据声阻抗在 0-4000 Hz 频率范围内绘制惯性图。惯性图预测哪些谐波可能会被加强。 结果喉部气道变窄和延长、咽部扩张以及管后口腔变窄的结合产生了俯仰滑行练习的最佳整体惯性图。此配置支持 300–4000 Hz 范围内均匀的源谐波。 结论对于临床应用，理论预测，如果内径约为 3 毫米或更小，则管子或吸管的长度并不重要。对于更宽的开口管，更大的长度可以补偿更宽的直径以获得有益的惯性效应，但是无法维持声带姿势所需的气道中的稳定压力。