Research on Acoustic Approach of Speech Quality Model

在语音生成系统中，我们研究了声道三维图形参数与真实语音质量之间的关系。对于声源上频率变化的不同音高重音元音，对声门关闭对应的部分语音波形进行频谱分析；使用了几个成年雄性的数据。由于在声门闭合中采样数据的数量很少，使用序数方法分析数据很困难，我们采用了我们的新方法——使用映射的短时分析法。利用我们的方法，我们可以稳定地估计出声门闭合时的形成峰，并表明即使是孤立的元音，形成峰也可以随着音高的变化而移动。在此基础上，提出了一种新的声门波估计方法，并取得了良好的估计效果。本文采用有限元法对MRI测量的声道形状模型进行了声学分析的数值模拟。通过有限元模拟，我们研究了声道形状参数、声门附近的小窦和声道壁阻抗对声道频谱特征的影响。结果表明，光谱受形状参数变化、小鼻窦和唇部辐射阻抗的影响；尤其是在更高的频率上。

In the speech production system, we investigated the relation between the parameters of 3-D figure of the vocal tract and the speech quality of real speech. For vowels with different pitch accent as frequency variation on acoustic source, spectral analysis is performed for the part of the speech waveform corresponding the glottal closure ; the data of the several male adults are used. Since the number of the sampled data is very small in the glottal closure, it is so diffcult to analyze the data using ordinal method, we adopted our new method of the short-time analysis method using the mapping. Using our method, we could estimate stably the formant in the glottal closure, and showed that even for isolated vowels the formant can be moved by the pitch variation. Moreover, we showed a new estimation method for the glottal wave by using our analysis algorithm, and excellent result on the estimation.Using Finite Element Method (FEM), we performed numerical simulation of acoustical analysis for the shape model of the vocal tract which was measured by MRI.By this FEM simulation, we investigated the effect of shape parameters, small sinuses near the glottis, and wall impedance of vocal tract for the spectral characteristics. As the result, we showed that the spectrum is influenced by the variation of the shape parameters and the small sinuses, and by the radiation impedance at the lips ; especially on higher formants.