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，该技术将具有基本上听不见的热噪声和电子噪声。这些定向麦克风的噪音将通过以下三种新技术的集成来显著降低：1)开发一种具有低热噪声的坚固的、受生物启发的麦克风隔膜。具有理想的无噪声电子放大的麦克风，由于热激发空气分子对隔膜的随机影响，在其输出中仍然会产生噪声。周围气体向隔膜传递能量的能力直接关系到振动阻尼的量，或系统中的被动能量耗散。在提出的研究中，优化的低阻尼和低噪声隔膜设计将被开发出来，以创造一种具有更低热噪声的定向麦克风隔膜，并提高对声音的灵敏度，这是目前可用技术无法实现的。2)光学传感，将膜片运动转换为电子信号。在提出的努力中，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高灵敏度、低噪声的方法，从仿生麦克风隔膜获得电子输出，增加的电子噪声可以忽略不计。将开发一种小型化封装方案，将光电元件与麦克风隔膜集成在一起。3)电子反馈降噪。如上所述，本研究的一个关键贡献将是开发具有最小被动阻尼的定向麦克风隔膜。虽然低阻尼导致低噪声，但它也导致高度共振，振铃响应，这在麦克风中当然是不希望的。在提议的努力中，将开发一个电子反馈系统，以结合电子阻尼，以实现阻尼的理想响应效益，而不会产生相关的热噪声。这种降低热噪声和主动响应控制的方法已在其他低噪声传感应用中采用，但以前在麦克风应用中并不可行。低阻尼定向传声器膜片与光学传感方案的结合，使得在低噪声微型传声器的设计中利用这一强大的技术成为可能。

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.