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

本研究的目的是创建一种微型声速传感器，当与 传统的微型压力麦克风将能够精确测量耳声学 人耳道内的发射和宽带中耳反射率。这些数量揭示了 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 麦克风的压力对测量位置有很强的依赖性。这个 研究将能够同时检测声学粒子速度和声压 提供比现有技术更可重复、更可靠的耳声发射测量 方法。 现有的测量耳道内生理相关声音的方法也受到影响，因为 这些声音通常非常安静，接近于微型麦克风的本底噪声。 最先进的耳声发射测量系统。拟议的努力将使 检测到的耳声发射水平比目前可行的水平至少低 10 dB。降低 测量本底噪声将减少从噪声中提取这些信号所需的平均时间 并能够检测更安静的耳声发射，这对于受试者来说很重要 患有听力损失。扩展我们测量人耳道中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 对于听力受损的人。 这项研究是研究人员最近发现的延伸，即纳米级纤维可以 由粘性力驱动，使得它们的声引起的振动几乎与 声场中的空气。空气速度驱动电极的运动将使用其新的技术进行检测 电容式传感方法适用于高度兼容的结构，例如使用的结构 在这里。 然后，新型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。使用此方法获得的人耳道声学测量结果 然后将低噪声且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.