In Vivo Measures of Vocal Function Response to Environmental Conditions

描述(由申请人提供)：几乎没有科学证据支持常用的嗓音障碍临床治疗策略。临床医生经常建议增加环境湿度，适当补水，避免干燥或炎热的环境，这些策略被认为可以促进最佳发声功能和发声舒适感。然而，对于环境参数，特别是环境温度、湿度和蒸汽压的相互依赖如何影响声音，目前还没有很好的理解。由于这些变量的相互依赖，在研究喉组织功能时，很难研究单一的环境因素(例如湿度)。在以前的语音功能研究中，还没有系统地研究温度、蒸汽压和湿度之间的相互关系。这项拟议研究的跨学科设计将调查环境温度和蒸汽压对发声功能的影响，这两个因素共同影响相对湿度。这种同时测量喉部环境温度(咽部热敏温度探头和红外热成像)和临床发声功能测量(发声阈值、压力和感觉发声努力)的新应用允许系统地研究环境条件和增加的通气量对发声组织功能的影响。这项研究的假设是，与热中性条件相比，环境条件(温度、蒸汽压、湿度)的变化与发声的压力阈值(发声阈值压力)和努力感觉的增加有关。这项工作有两个具体的目标：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、喉部局部温度以及口鼻吸入时的发声舒适感。这可能会影响呼吸道湿度和组织水分含量。2)采用受试者内重复测量设计，确定次极量有氧运动引起的通气量增加(喉区对流气流)对喉温和发声效率的影响是否不同于静息鼻呼吸。考虑到进入喉部组织的解剖学和生理学方面的挑战，在不同的环境条件下测量喉部热环境和声带组织功能将有助于我们理解在不同于典型临床环境的中性环境条件下的冷暖环境中的声音使用。这项工作将阐明对喉部组织的环境要求，并为指导临床发声康复和在现实环境条件下有效、安全地使用发声提供依据。 与公共健康相关：已发表的研究表明，我们呼吸的空气的相对湿度可能会影响我们使用声音的容易程度；然而，我们还不知道环境温度和湿度与嗓音盒(喉部)内组织的相互依赖关系。这种关系可能依赖于空气蒸汽压(空气冷凝或蒸发的点)，这是我们理解喉部如何在健康和疾病中调节声带组织水分的关键组成部分。考虑到环境对发声盒肌肉和组织的影响，可能有助于我们理解如何最好地训练或恢复发声，以适应需要广泛发声或在极端温度环境下使用发声的工作。

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.