Abstract:
The current work investigated the effects of mass-loading the eardrum on wideband absorbance in humans. A non-invasive approach to mass-loading the eardrum was utilized in which water was placed on the eardrum via ear canal access. The mass-loaded absorbance was compared to absorbance measured for two alternative middle ear states: normal and stiffened. To stiffen the ear, subjects pressurized the middle ear through either exsufflation or insufflation concurrent with Eustachian tube opening. Mass-loading the eardrum was hypothesized to reduce high-frequency absorbance, whereas pressurizing the middle ear was hypothesized to reduce low- to mid-frequency absorbance. Discriminant linear analysis classification was performed to evaluate the utility of absorbance in differentiating between conditions. Water on the eardrum reduced absorbance over the 0.7- to 6-kHz frequency range and increased absorbance at frequencies below approximately 0.5 kHz; these changes approximated the pattern of changes reported in both hearing thresholds and stapes motion upon mass-loading the eardrum. Pressurizing the middle ear reduced the absorbance over the 0.125- to 4-kHz frequency range. Several classification models based on the absorbance in two- or three-frequency bands had accuracy exceeding 88%.
摘要:
当前的工作研究了质量加载鼓膜对人类宽带吸收的影响。利用非侵入性方法对鼓膜进行质量加载,其中通过耳道进入将水放置在鼓膜上。将质量加载的吸光度与针对两种替代的中耳状态测量的吸光度进行比较:正常和变硬。为了使耳朵变硬,受试者通过排气或吹气同时咽鼓管开口对中耳加压。假设鼓膜的质量负荷可以减少高频吸收,而假设对中耳加压可以减少低频到中频的吸收。进行判别式线性分析分类以评估吸光度在区分条件中的效用。鼓膜上的水在0.7至6kHz的频率范围内降低了吸光度,在低于约0.5kHz的频率下增加了吸光度;这些变化近似于在耳膜质量加载时听力阈值和the骨运动中报告的变化模式。加压中耳降低了0.125-4kHz频率范围内的吸光度。基于两个或三个频带中的吸光度的几种分类模型的准确性超过88%。