ON SUBGLOTTAL FORMANT ANALYSIS
ON SUBGLOTTAL FORMANT ANALYSIS
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DOI：
10.1121/1.394842
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发表时间：
1987-03-01
影响因子：
2.4
通讯作者：
BOVES, L
中科院分区：
文献类型：
--
作者：
CRANEN, B;BOVES, L
当对正常语音产生期间记录的声门下压力信号进行频谱分析时，第一谱最大值的频率似乎明显偏离文献中已报道的第一共振频率，这源于对声门下系统的声阻抗的测量。假设这是由激发函数的频谱引起的。这一假设得到了一项模型研究的证实。使用可以解释声门泄漏的众所周知的声带两质量模型的扩展版本，结果表明，在现实的生理学假设下，产生的声门流动波形的频谱特性导致声门下压力信号中第一谱最大值的位置下移。对于不同的声门设置和根据文献报道的阻抗测量而建模的声门下系统，研究了这种效应的数量级。该模拟研究的结果表明，声门下压力的第一个频谱最大值的位置可能会明显偏离声门下系统的固有频率。然而，结果是，令人满意的假设，即在正常语音中，声门兴奋函数在“关闭声门间隔”期间是恒定的和零的，必须受到质疑。
When subglottal pressure signals which are recorded during normal speech production are spectrally analyzed, the frequency of the first spectral maximum appears to deviate appreciably from the first resonance frequency which has been reported in the literature and which stems from measurements of the acoustic impedance of the subglottal system. It is postulated that this is caused by the spectrum of the excitation function. This hypothesis is corroborated by a modeling study. Using an extended version of the well-known two-mass model of the vocal folds that can account for a glottal leak, it is shown that under realistic physiological assumptions glottal flow waveforms are generated whose spectral properties cause a downward shift of the location of the first spectral maximum in the subglottal pressure signals. The order of magnitude of this effect is investigated for different glottal settings and with a subglottal system that is modeled according to the impedance measurements reported in the literature. The outcomes of this modeling study show that the location of the first spectral maximum of the subglottal pressure may deviate appreciably from the natural frequency of the subglottal system. As a consequence, however, the comfortable assumption that in normal speech the glottal excitation function is constant and zero during the "closed glottis interval" has to be called into question.