Titze I R
Department of Speech Pathology and Audiology, University of Iowa, Iowa City 52242.
J Acoust Soc Am. 1992 May;91(5):2926-35. doi: 10.1121/1.402928.
Phonation threshold pressure has previously been defined as the minimum lung pressure required to initiate phonation. By modeling the dependence of this pressure on fundamental frequency, it is shown that relatively simple aerodynamic relations for time-varying flow in the glottis are obtained. Lung pressure and peak glottal flow are nearly linearly related, but not proportional. For this reason, traditional power law relations between vocal power and lung pressure may not hold. Glottal impendance for time-varying flow should be defined differentially rather than as a simple ratio between lung pressure and peak flow. It is shown that the peak flow, the peak flow derivative, the open quotient, and the speed quotient of inverse-filtered glottal flow waveforms all depend explicitly on phonation threshold pressure. Data from singers are compared with those from nonsingers. The primary difference is that singers obtain two to three times greater peak flow for a given lung pressure, suggesting that they adjust their glottal or vocal tract impedance for optimal flow transfer between the source and the resonantor.
发声阈压力此前被定义为启动发声所需的最小肺压。通过对该压力与基频的依赖关系进行建模，结果表明，对于声门中随时间变化的气流，可获得相对简单的空气动力学关系。肺压与声门峰值气流近似呈线性相关，但并非成正比。因此，传统的声功率与肺压之间的幂律关系可能不成立。对于随时间变化的气流，声门阻抗应以微分方式定义，而不是简单地定义为肺压与峰值气流之比。结果表明，逆滤波后的声门气流波形的峰值气流、峰值气流导数、开放商和速度商均明确依赖于发声阈压力。将歌手的数据与非歌手的数据进行了比较。主要差异在于，对于给定的肺压，歌手获得的峰值气流要大两到三倍，这表明他们会调整声门或声道的阻抗，以实现声源与共鸣器之间的最佳气流传输。
