In Vivo Measures of Vocal Function Response to Environmental Conditions

描述（由申请人提供）：很少有科学证据支持常用的声音障碍临床治疗策略。临床医生通常建议增加环境湿度，适当的水合作用，避免干燥或热挑战的环境，这些策略被认为可以促进最佳的声音功能和声音放松的感知。然而，人们对环境参数，特别是环境温度、湿度和蒸汽压的相互依存关系如何影响声音还没有很好的理解。由于这些变量的相互依赖性，在研究喉部组织功能时，很难研究单一的环境因素（例如湿度）。在之前的语音功能研究中，温度、蒸汽压和湿度的相互关系还没有得到系统的研究。拟议研究的跨学科设计将调查环境温度和蒸汽压对相对湿度的影响，对声音功能的影响。这种将喉环境温度（咽热敏器温度探头和红外热成像）与发声功能（发声阈压和感知发声力度）的临床测量同时进行的新应用，可以系统地研究环境条件和通气率增加对发声组织功能的影响。本研究的假设是，与热中性条件相比，环境条件（温度、蒸汽压、湿度）的变化与发声开始的压力阈值（发声阈值压力）的增加和努力感的增加有关。这项工作有两个具体目的：1)使用受试者内重复测量设计确定环境温度、蒸汽压和湿度的变化是否影响发声开始、局部喉部温度以及口鼻吸入时声音放松的感觉。这可能会影响气道湿度和组织水分含量。2)采用受试者内重复测量设计，确定次最大有氧运动诱导的通气率（喉区对流气流）增加对喉区温度和发声开始效率的影响是否与静息鼻腔呼吸不同。考虑到喉组织解剖和生理上的挑战，喉热环境和声带组织功能在不同环境条件下的测量将有助于我们理解不同于典型临床中性环境条件的冷热环境下的语音使用。这项工作将阐明对喉部组织的环境要求，并为指导临床语音康复和在现实环境条件下有效、安全地使用语音提供证据。

DESCRIPTION (provided by applicant): There is little scientific evidence to support commonly used clinical treatment strategies for voice disorders. Clinicians routinely recommend increased ambient humidity, proper hydration, and avoidance of dry or thermally challenging environments, strategies that are believed to promote best vocal function and perception of vocal ease. However, there is not a good understanding of how environmental parameters, specifically the interdependence of ambient temperature, humidity, and vapor pressure affect the voice. Due to the interdependence of these variables, it is difficult to investigate a single environmental factor (e.g., humidity) when studying laryngeal tissue functions. The interrelatedness of temperature, vapor pressure, and humidity has not been systematically studied in prior investigations of voice function. The interdisciplinary design of the proposed research will investigate the influence of ambient temperature and vapor pressure, which collectively influence relative humidity, on vocal function. This novel application of concurrent measures of laryngeal environment temperature (pharyngeal thermister temperature probe and infrared thermal imaging) with clinical measures of vocal function (phonation threshold pressure and perceived vocal effort) allows for systematic study of the effect of environmental conditions and increased ventilation rate on vocal tissue function. The hypothesis of this study is that alterations in ambient conditions (temperature, vapor pressure, humidity) are associated with increased pressure thresholds (phonation threshold pressure) for phonatory onset and increased perception of effort when compared with a thermally neutral condition. This work has two specific aims: 1) To determine if changes in ambient temperature, vapor pressure, and humidity influence phonatory onset, regional laryngeal temperature, and perception of vocal ease for mouth versus nose inhalation using a within-subject repeated measures design. This may influence airway humidity and tissue moisture content. 2) To determine if increased ventilation rate (convective airflow within laryngeal region) induced by submaximal aerobic exercise influences regional laryngeal temperature and efficiency of phonatory onset differently than resting nasal breathing using a within-subject repeated measures design. Given the anatomical and physiological challenges of accessing the laryngeal tissues, measurements of the laryngeal thermal environment and vocal fold tissue function under varying ambient environmental conditions will contribute to our understanding of voice use in cold and warm environments that differ from the neutral environmental conditions of the typical clinic setting. This work will elucidate the environmental demands placed on the laryngeal tissue and provide evidence to guide clinical voice rehabilitation and habilitation of effective, safe voice use under realistic environmental conditions. PUBLIC HEALTH RELEVANCE: Published research indicates that the relative humidity of the air we breathe may influence how easily we use our voice; however, we do not yet understand the interdependent relationship of environmental temperature and humidity on tissues within the voice box (larynx). This relationship may be dependent upon the air vapor pressure (point at which air condenses or evaporates), which is a crucial component of our understanding of how the larynx adjusts the moisture of the vocal tissues in health and disease. Accounting for environmental impact on the muscles and tissues of the voice box may help us understand how to best train or rehabilitate the voice for work that requires extensive voice use or voice use in extreme temperature environments.