Farley G R
Boys Town National Research Hospital, Omaha, Nebraska 68131.
J Acoust Soc Am. 1994 Feb;95(2):1017-29. doi: 10.1121/1.408465.
A mathematical model of the larynx, based on biomechanical principles, is described. Components represented include two cartilage elements (cricoid with locked arytenoids, and thyroid), three muscles (thyroarytenoid [TA], cricothyroid pars rectus [CTr], and cricothyroid pars oblique [CTo]), and two ligaments (cricothyroid and vocal ligaments), as well as subglottal pressure (PS). For any combination of muscle activities and PS level, equilibrium positions and tensions could be calculated for components in the system. The tensions and lengths of vocal fold elements were then used to calculate fundamental frequency (F0) of vocal fold vibration. Systematic variation of model muscle activation and PS patterns allowed study of the behavior of the model. TA activity tended to shorten the vocal folds; increased levels of CTr and CTo activity, and PS, had the opposite effect. Increased activity of any muscle tended to increase vocal fold tension, while PS increases were mainly ineffective. F0 was generally increased by increased CTr, CTo, and PS values. However, TA activity had a strongly nonmonotonic effect on F0. Best control of F0 could be achieved only by a process of co-contraction of all muscles at low frequencies, followed by sustained contraction of CTr and CTo with decreasing TA activity for F0's increasing above this low-frequency range. These results are discussed in terms of their possible implications for norma and abnormal voice production, and as a set of constraints for neural modeling efforts.
描述了一种基于生物力学原理的喉部数学模型。所表示的组成部分包括两个软骨元件（环状软骨与固定的杓状软骨，以及甲状软骨）、三块肌肉（甲杓肌[TA]、环甲肌直部[CTr]和环甲肌斜部[CTo]）、两条韧带（环甲韧带和声带韧带），以及声门下压力（PS）。对于肌肉活动和PS水平的任何组合，可以计算系统中各组成部分的平衡位置和张力。然后利用声带元件的张力和长度来计算声带振动的基频（F0）。通过系统改变模型肌肉激活和PS模式，可以研究模型的行为。TA活动倾向于缩短声带；CTr和CTo活动水平的增加以及PS则产生相反的效果。任何一块肌肉活动的增加都倾向于增加声带张力，而PS的增加主要无效。一般来说，CTr、CTo和PS值的增加会使F0升高。然而，TA活动对F0有强烈的非单调影响。只有通过在低频时所有肌肉共同收缩，然后随着F0在该低频范围以上增加，CTr和CTo持续收缩而TA活动减少的过程，才能实现对F0的最佳控制。将根据这些结果对正常和异常发声的可能影响进行讨论，并作为神经建模工作的一组约束条件。
