Švec Jan G, Zhang Zhaoyan
Department of Experimental Physics, Faculty of Science, Palacky University Olomouc, Olomouc 77900, Czech Republic.
Department of Head and Neck Surgery, University of California Los Angeles, Los Angeles, CA 90095-1794, USA.
Philos Trans R Soc Lond B Biol Sci. 2025 Apr 3;380(1923):20240018. doi: 10.1098/rstb.2024.0018.
The theory of nonlinear dynamics was introduced to voice science in the 1990s and revolutionized our understanding of human voice production mechanisms. This theory elegantly explains highly complex phenomena in the human voice, such as subharmonic and rough-sounding voice, register breaks, and intermittent aphonic breaks. These phenomena occur not only in pathologic, dysphonic voices but are also explored for artistic purposes, such as contemporary singing. The theory reveals that sudden changes in vocal fold vibratory patterns and fundamental frequency can result from subtle alterations in vocal fold geometry, mechanical properties, adduction, symmetry or lung pressure. Furthermore, these changes can be influenced by interactions with supraglottal tract and subglottal tract resonances. Crucially, the eigenmodes (modes of vibration) of the vocal folds play a significant role in these phenomena. Understanding how the left and right vocal fold eigenmodes interact and entrain with each other, as well as their interplay with supraglottal tissues, glottal airflow and acoustic resonances, is essential for more sophisticated diagnosis and targeted treatment of voice disorders in the future. Additionally, this knowledge can be helpful in modern vocal pedagogy. This article reviews the concepts of nonlinear dynamics that are important for understanding normal and pathologic voice production in humans.This article is part of the theme issue 'Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions'.
非线性动力学理论于20世纪90年代被引入语音科学领域，彻底改变了我们对人类语音产生机制的理解。该理论巧妙地解释了人类语音中高度复杂的现象，如次谐波和粗糙声音、声区断裂以及间歇性失声。这些现象不仅出现在病理性发声障碍的声音中，也被用于艺术目的，如当代歌唱。该理论表明，声带振动模式和基频的突然变化可能源于声带几何形状、机械性能、内收、对称性或肺压力的细微改变。此外，这些变化会受到与声门上气道和声门下气道共振相互作用的影响。至关重要的是，声带的本征模式（振动模式）在这些现象中起着重要作用。了解左右声带本征模式如何相互作用和同步，以及它们与声门上组织、声门气流和声学共振的相互作用，对于未来更精确地诊断和针对性治疗语音障碍至关重要。此外，这些知识对现代声乐教学也有帮助。本文回顾了对理解人类正常和病理性语音产生至关重要的非线性动力学概念。本文是主题为“脊椎动物发声中的非线性现象：机制与交流功能”的一部分。
