Low-noise directional hearing aid microphones using optical sensing with electron

描述（由申请人提供）：拟议研究的长期目标是开发用于助听器的定向麦克风的技术，该麦克风基本上具有听不见的热噪声和电子噪声。这些指向性麦克风的噪声的显著降低将通过三种新技术的集成来实现：1）开发具有低热噪声的坚固的生物启发麦克风振膜。由于热激发的空气分子对振膜的随机冲击，具有理想的无噪声电子放大的麦克风在其输出中仍然会产生噪声。周围气体将能量传递给隔膜的能力与系统中的振动阻尼或被动能量耗散的量直接相关。在所提出的研究中，将开发优化的低阻尼和低噪声振膜设计，以创建定向麦克风振膜，该定向麦克风振膜具有比当前可用技术所能实现的低得多的热噪声沿着增加的对声音的灵敏度。2)光学传感将膜片运动转换为电子信号。在拟议的努力中，将开发一种革命性的低噪声光学方法，用于将膜片的运动转换为电子信号。这种光学方案提供了一种从生物激励麦克风振膜获得电子输出的高灵敏度、低噪声方法，该方法增加了可忽略的电子噪声。一个小型化的封装方案将开发集成的光电元件与麦克风膜片。3)用于降低热噪声的电子反馈。如上所述，本研究的一个关键贡献将是具有最小被动阻尼的定向麦克风振膜的发展。虽然低阻尼导致低噪声，但它也导致高谐振、振铃响应，这在麦克风中肯定是不期望的。在所提出的努力，电子反馈系统将被开发，以纳入电子阻尼，以实现理想的响应阻尼没有相关的热噪声的好处。这种热噪声降低和主动响应控制的方法已经在其他低噪声感测应用中被采用，但它以前在麦克风应用中不可行。低阻尼、定向麦克风振膜与此处开发的光学传感方案相结合，使其能够在低噪声微型麦克风的设计中利用这一强大的技术。

DESCRIPTION (provided by applicant): The long-term objective of the proposed research is to develop technology for the creation of directional microphones for hearing aids that will have essentially inaudible thermal and electronic noise. The dramatic reduction in the noise of these directional microphones will be accomplished by the integration of three novel technologies: 1) The development of a robust, biologically-inspired microphone diaphragm having low thermal noise. Microphones having ideal, noiseless electronic amplification will still produce noise in their output due to the random impacts of thermally excited air molecules on the diaphragm. The ability of the surrounding gas to impart energy to the diaphragm is directly related to the amount of vibration damping, or passive energy dissipation in the system. In the proposed study, optimized low-damping, and hence low-noise, diaphragm designs will be developed to create a directional microphone diaphragm having much lower thermal noise along with increased sensitivity to sound than can be achieve by currently available technology. 2) Optical sensing to convert the diaphragm motion into an electronic signal. In the proposed effort, a revolutionary low-noise optical method will be developed for converting the motion of the diaphragm into an electronic signal. This optical scheme provides a highly sensitive, low-noise method of obtaining an electronic output from the bio-inspired microphone diaphragms that adds negligible electronic noise. A miniaturized packaging scheme will be developed to integrate the optoelectronic components with the microphone diaphragm. 3) Electronic feedback for thermal noise reduction. As mentioned above, a key contribution of this research will be the development of directional microphone diaphragms having a minimum of passive damping. While low damping leads to low noise, it also leads to highly resonant, ringing response, which is certainly undesirable in a microphone. In the proposed effort, an electronic feedback system will be developed to incorporate electronic damping to achieve the desirable response benefits of damping without the associated thermal noise. This approach to thermal noise reduction and active response control has been adopted in other low-noise sensing applications but it has previously not been feasible in microphone applications. The combination of the low damping, directional microphone diaphragm and the optical sensing scheme to be developed here makes it possible to take advantage of this powerful technology in the design of low-noise miniature microphones.