Stretching and break-up of saliva filaments during speech: A route for pathogen aerosolization and its potential mitigation
Stretching and break-up of saliva filaments during speech: A route for pathogen aerosolization and its potential mitigation
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DOI：
10.1103/physrevfluids.5.102301
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发表时间：
2020-10-02
影响因子：
2.7
通讯作者：
Stone, H. A.
中科院分区：
文献类型：
--
作者：
Abkarian, M.;Stone, H. A.
言语是 COVID-19 大流行中病毒传播的有效途径。由于口腔中尚未观察到雾化机制，因此很难制定明智的缓解策略。在这里，我们通过高速成像展示了世界上大多数口语中常见的塞音的发音如何在湿润的嘴唇张开或舌头与牙齿分离时在几毫秒内形成和延伸唾液丝。唾液粘弹性和与塞音辅音爆裂相关的气流对于稳定并随后形成直径为数十微米的厘米级细丝至关重要，这些细丝会分解成语音液滴。此外，这些爆破辅音会产生涡环，驱动呼出空气的一米长传输，将这种机制与与语音相关的传输联系起来。我们证明了类似的气雾化机制发生在管乐器中的簧片振动过程中，并且可能发生在声门皱襞拍打过程中。最后，我们的研究建议通过使用润唇膏来减少讲话过程中液滴的产生。
Speech is a potent route for viral transmission in the COVID-19 pandemic. Informed mitigation strategies are difficult to develop since no aerosolization mechanism has been visualized yet in the oral cavity. Here we show with high-speed imaging how phonation of common stop consonants, found in most of the world's spoken languages, form and extend salivary filaments in a few milliseconds as moist lips open or when the tongue separates from the teeth. Both saliva viscoelasticity and airflow associated with the plosion of stop consonants are essential for stabilizing and subsequently forming centimeter-scale thin filaments, tens of microns in diameter, that break into speech droplets. Moreover, these plosive consonants induce vortex rings that drive meter-long transport of exhaled air, tying this mechanism to transport associated with speech. We demonstrate that a similar mechanism of aerosolization occurs during the vibration of reeds in wind instruments and may occur during the flapping of the glottis folds. Finally, our research suggests a mitigation of droplet production during speech by using a lip balm.