Ziegler Aaron, VanSwearingen Jessie, Jakicic John M, Verdolini Abbott Katherine
Department of Otolaryngology-Head & Neck Surgery, Oregon Health & Science University, Portland.
Department of Physical Therapy, University of Pittsburgh, PA.
J Speech Lang Hear Res. 2019 Aug 15;62(8):2584-2600. doi: 10.1044/2019_JSLHR-S-18-0126. Epub 2019 Jul 10.
Purpose This study investigated whether metabolic respiratory requirements (treadmill workload) affected glottal valving in phonation, based on aerodynamic measures, when a sound pressure level (vocal SPL) is dictated as a target goal. Consistent with a theory of action, we hypothesized that adjustments in glottal valving as measured by laryngeal airway resistance would be dependent upon vocal SPL level, even as workload increased, and loud vocal SPL would interfere more with respiratory homeostasis than spontaneous vocal SPL. Method Thirty-two women enrolled who were ages 18-35 years. A repeated-measures design was used with random assignment of workload and vocal SPL conditions. Aerodynamic and acoustic data were collected during phonation, as were gas volume and concentration data. Analyses were performed with generalized estimating equations. Results Laryngeal airway resistance at a low workload significantly increased when vocal SPL changed from spontaneous to loud. At a loud vocal SPL, laryngeal airway resistance decreased when workload changed from rest to either low or high. Regarding the respiratory system response, minute ventilation increased at a loud vocal SPL when workload changed from rest to either low or high. End-tidal CO increased under low and high workloads relative to rest at loud and spontaneous vocal SPLs. Conclusions Mostly consistent with a theory of action, in which motor control is goal dependent (i.e., vocal SPL targets), speakers can achieve a loud vocal SPL despite increases in workload requirements. In contrast, laryngeal airway resistance stays relatively low when vocal SPL occurs spontaneously, suggesting glottal adjustments are made to improve gas exchange as metabolic respiratory requirements become prioritized. Metabolic respiratory requirements appear to be overcome by the overlay of motor control for voicing when a loud vocal SPL is targeted. The implication of goal-dependent phonation for clinicians is that real-world conditions (i.e., loud vocal SPL) matter in vocal testing and voice therapy.
目的 本研究基于空气动力学测量，探讨当声压级（嗓音声压级）被设定为目标值时，代谢性呼吸需求（跑步机负荷）是否会影响发声时的声门瓣控。与行动理论一致，我们假设，即使负荷增加，通过喉气道阻力测量的声门瓣控调整也将取决于嗓音声压级水平，并且高声压级嗓音比自发嗓音声压级对呼吸稳态的干扰更大。方法 招募了32名年龄在18至35岁之间的女性。采用重复测量设计，随机分配负荷和嗓音声压级条件。在发声过程中收集空气动力学和声学数据，以及气体体积和浓度数据。使用广义估计方程进行分析。结果 当嗓音声压级从自发变为高声时，低负荷下的喉气道阻力显著增加。在高声压级嗓音时，当负荷从休息状态变为低负荷或高负荷时，喉气道阻力降低。关于呼吸系统反应，当负荷从休息状态变为低负荷或高负荷时，高声压级嗓音时的分钟通气量增加。在高声压级嗓音和自发嗓音声压级下，相对于休息状态，低负荷和高负荷时的呼气末二氧化碳增加。结论 大多与行动理论一致，即运动控制取决于目标（即嗓音声压级目标），尽管负荷需求增加，说话者仍可实现高声压级嗓音。相比之下，自发产生嗓音声压级时，喉气道阻力保持相对较低，这表明当代谢性呼吸需求被优先考虑时，会进行声门调整以改善气体交换。当目标是高声压级嗓音时，代谢性呼吸需求似乎被发声的运动控制所覆盖。目标依赖发声对临床医生的意义在于，现实世界的条件（即高声压级嗓音）在嗓音测试和嗓音治疗中很重要。
