Capacitive Pressure/Velocity Probe for Acoustic Measurements in the Human Ear Canal

这项研究的目的是创造一种微型声速传感器，当与 传统的微型压力传声器将使耳声的准确测量成为可能 人体耳道内的辐射和宽带中耳反射。这些量揭示了 有关外周听觉系统功能状态的重要信息。 使用声压在耳道内进行声学测量的现有方法 传声器的压力对测量位置有很强的依赖性。这 研究将使声质点速度与声压同时检测 提供了比现有耳声发射更可重复和更可靠的测量 方法：研究方法。 现有的测量耳道内生理相关声音的方法也受到了影响，因为 这些声音通常非常安静，靠近使用的微型麦克风的噪音地板 最先进的耳声发射测量系统。拟议的努力将使 在比目前可行的水平低至少10分贝的水平上检测耳声发射。降低 测量噪声下限将减少从噪声中提取这些信号所需的平均时间 并能够检测到更安静的耳声发射，这在受试者中可能是重要的 并伴有听力损失。扩大我们在人类耳道中测量这些重要声音的能力将 导致中耳和内耳功能的新发现，并将提供极大改进的临床工具 为听力受损的人准备的。 这项研究包括研究人员最近一项发现的扩展，即纳米级纤维可以 由粘性力驱动，这样它们的声音诱导的振动可以几乎与 声场中的空气。空气速度驱动电极的运动将被检测到使用它们的新的 适用于高顺应性结构(如使用的结构)的电容传感方法 这里。 然后，新的声速传感器将与低噪声微型助听器结合在一起 测量设备中的麦克风。利用这一技术对人耳道进行声学测量 然后，将低噪声和稳健的系统与使用现有方法获得的系统进行比较。

The aim of this research is to create a miniature acoustic velocity sensor which, when combined with a conventional miniature pressure microphone will enable accurate measurements of otoacoustic emissions and wideband middle-ear reflectance within the human ear canal. These quantities reveal important information about the functional status of the peripheral auditory system. Existing methods of making acoustic measurements within the ear canal using sound pressure microphones suffer from the strong dependence of pressure on the measurement location. This research will enable the detection of acoustic particle velocity simultaneously with sound pressure providing a much more repeatable and reliable measure of otoacoustic emissions than existing methods. Existing methods for measuring physiologically relevant sounds in the ear canal also suffer because these sounds are often very quiet, close to the noise floors of the miniature microphones employed in state-of-the-art systems for measuring otoacoustic emissions. The proposed effort will enable the detection of otoacoustic emissions at levels at least 10 dB lower than currently feasible. Lowering the measurement noise floor will reduce the averaging time necessary to extract these signals from noise and enable the detection of much quieter otoacoustic emissions, which can be important in subjects with hearing loss. Extending our ability to measure these important sounds in the human ear canal will lead to new discoveries of middle and inner ear function and will provide greatly improved clinical tools for the hearing impaired. This research comprises an extension of a recent discovery by the investigators that nanoscale fibers can be driven by viscous forces such that their sound-induced vibrations can be nearly identical to that of the air in a sound field. The motion of air velocity-driven electrodes will be detected using their new approach to capacitive sensing that is appropriate for highly compliant structures such as those used here. The novel acoustic velocity sensor will then be incorporated with a low-noise miniature hearing aid microphone in a measurement device. Acoustic measurements in human ear canals obtained using this low-noise and robust system will then be compared to those obtained using existing methods.