Study on Refined Mechanism Model of Phonation : A Model Taking Vibration of the Vocal Folds and the Resonance in the Vocal Tract into Account

在人类发声过程中，声源是由声带运动与流经声门的气流相互作用而产生的自激振荡产生的，声门是左右声带之间的缝隙。在以往的分析中，我们收集了与自激振荡直接相关的分离和振动气流的基本数据，并对正常发声进行了数值分析。考虑声带振动的力学分析有望从力学的角度对发声进行研究，特别是诊断由息肉等疾病引起的左右声带性质不平衡引起的复杂声音障碍，以及在切除癌性声带后产生声源的人工喉头和食管语音技术的发展。为了探讨由疾病引起的左右声带性质失衡导致的发声障碍的复杂行为机制，我们扩展了我们的实验和理论模型发声。在项目期间（1998- 1999财年），我们进行了以下研究：1。我们设计了一个具有非对称振动收缩的准二维通道模型。我们购买了一台激光位移仪来测量收缩的运动，并购买了高精度的压力传感器和放大器进行精确测量，并收集了基本但精细的稳态和非稳态静压、流量等数据。在实验数据的基础上，提出了声带不对称振动的理论模型。利用该理论模型，对振动压力、振动速度分布等进行了数值计算。对正常和异常声音进行了测量，并将实验数据与数值结果进行了比较，对测量方法和提出的理论模型进行了评价。

In voice production of human being, source is produced by self-excited oscillation occurred due to interaction of motion of the vocal folds and a flow through the glottis which is a slot between the left and right vocal fold. In our previous analyses we have collected fundamental data of separated and vibratory air flow which relates the self-excited oscillation directly and performed numerical analysis of normal phonation.Mechanical analyses taking vocal-fold vibration into account is expected to contribute the study on phonation from the mechanical point of view, especially, diagnosis of complicated voice disorders due to property imbalance of the left and right vocal fold caused by diseases such as polyps, and development of artificial-larynxes and esophageal-speech-techniques in which source sound is produced when cancerous vocal folds have been excised.In order to investigate the mechanism of complicated behaviors in the voice disorders due to property imbalance of the left and right vocal fold caused by the diseases, we extended our experimental and theoretical model phonation.We performed the following studies during the term of the project (FY1998-FY1999) :1. We designed a quasi-two-dimensional channel model with an asymmetrical vibratory constriction. We purchased a Laser displacement meter to measure the motion of the constriction and high-accuracy pressure transducers and amplifiers for accurate measurement, and collected fundamental but refined data on steady and unsteady static pressures, flow rate, and so forth.2. Based on the experimental data, we proposed a theoretical model of the vocal folds vibrating asymmetrically. Using this theoretical model, we numerically calculated vibratory pressure and velocity distribution, and so forth.3. We measured normal and abnormal voices, compared the experimental data with the numerical results, and evaluated the measuring methods and the proposed theoretical model.