喉振频不对称与神经肌肉补偿对嗓音质量的影响。
Effects of Laryngeal Vibratory Asymmetry and Neuromuscular Compensation on Voice Quality.
机构信息
Department of Head and Neck Surgery, University of California Los Angeles, Los Angeles, California, U.S.A.
Department of Linguistics, University of California Los Angeles, Los Angeles, California, U.S.A.
出版信息
Laryngoscope. 2022 Jan;132(1):130-134. doi: 10.1002/lary.29724. Epub 2021 Jul 3.
INTRODUCTION
Vibratory asymmetry and neuromuscular compensation are often seen in laryngeal neuromuscular pathology. However, the ramifications of these findings on voice quality are unclear. This study investigated the effects of varying levels of vibratory asymmetry and neuromuscular compensation on cepstral peak prominence (CPP), an analog of voice quality.
STUDY DESIGN
In vivo canine phonation model.
METHODS
Varying degrees of vocal fold vibratory asymmetry were achieved by stimulating one recurrent laryngeal nerve (RLN) over 11 levels from threshold to maximal muscle activation. For each of these levels, phonation was induced at systematically varied combinations of neuromuscular compensation: three levels each of contralateral RLN stimulation (80%, 90%, and 100% of maximal), superior laryngeal nerve (SLN) activation (0%, 50%, and 100% of maximal), and airflow levels (500, 700, and 900 mL/s). Vocal fold symmetry was determined by assessing the opening phase of the vibratory cycle in high-speed video recordings. Voice quality was estimated acoustically by calculating CPP for each voice sample.
RESULTS
Eight hundred twenty-two phonatory conditions with varying degrees of vibratory asymmetry were evaluated. CPP was highest at vibratory symmetry. Increasing levels of asymmetry resulted in significant decreases in CPP. CPP increased significantly with increasing contralateral RLN activation. CPP was significantly higher at 50% SLN activation than 0% or 100% SLN activation.
CONCLUSION
Voice quality, as approximated by CPP, is best at vibratory symmetry and deteriorates with increasing degrees of asymmetry. Voice quality may be improved with neuromuscular compensation by increased adduction of the contralateral vocal fold or increased vocal fold tension at mid-levels of SLN activation.
LEVEL OF EVIDENCE
NA, Basic Science Laryngoscope, 132:130-134, 2022.
简介
声带神经肌肉病变常出现振动不对称和神经肌肉代偿。然而，这些发现对嗓音质量的影响尚不清楚。本研究调查了不同程度的振动不对称和神经肌肉代偿对频谱峰突出度（CPP）的影响，CPP 是嗓音质量的一种模拟。
研究设计
体内犬科发声模型。
方法
通过刺激单侧喉返神经（RLN）从阈刺激到最大肌肉激活的 11 个水平，实现不同程度的声带振动不对称。对于这些水平中的每一个，通过系统地改变神经肌肉代偿的组合来诱导发声：对侧 RLN 刺激的三个水平（最大的 80%、90%和 100%）、喉上神经（SLN）激活的三个水平（最大的 0%、50%和 100%）和气流水平的三个水平（500、700 和 900mL/s）。通过评估高速视频记录中振动周期的开启阶段来确定声带的对称性。通过计算每个语音样本的 CPP 来评估语音质量的声学特性。
结果
评估了 822 种具有不同程度振动不对称的发音条件。在振动对称时，CPP 最高。不对称程度的增加导致 CPP 显著降低。随着对侧 RLN 激活水平的增加，CPP 显著增加。与 0%或 100%SLN 激活相比，50%SLN 激活时 CPP 显著更高。
结论
语音质量，如 CPP 所估计的，在振动对称时最佳，随着不对称程度的增加而恶化。通过增加对侧声带的内收或在 SLN 激活的中水平增加声带张力，神经肌肉代偿可能会改善语音质量。
证据水平
NA，基础科学喉镜，132：130-134，2022。
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