Piezoelectric MEMS microphones for hearing aids

描述（由申请人提供）：大约有3000万美国人患有听力损失，并将受益于某种形式的听力增强。然而，助听器（HA）的采用率很低，不到25% [Kochkin，（2009）]，并且那些采用助听器的人需要等待10年以上才能这样做[Donahue，（2010）]。使用率低和采用HA延迟时间长的原因有很多，包括有效性、价格、舒适度、尺寸和外观问题。显然，我们有需要改善听觉障碍人士的服务，使他们能得到更有效的协助，透过更佳的治疗，改善生活质素和生产力。这项建议旨在为医管局的应用开发一种新的麦克风，作为改善医管局效率和提高使用率的一个途径。特别是，将开发第一个压电微机电系统（MEMS）麦克风，满足助听器行业严格的声学规范。该资助的三个具体目标是：（1）设计和制造MEMS压电换能器元件，（2）设计和制造用于读出换能器电信号的放大电子器件，以及（3）为符合HA应用要求的机械和电气元件设计适当的外壳。与现有的基于驻极体电容传声器（ECM）的技术相比，这种新型传声器将：对外部环境更加稳健，长期稳定，易于助听器组装，并以更小的尺寸提供上级声学性能。由于用于创建该器件的MEMS制造基于半导体工业中使用的相同工艺，因此一旦这些器件的设计完善，它们就可以以低成本制造并且容易地与处理电子器件集成。我们的最终目标是开发一种麦克风，提供更好的声学性能比目前的HA在成本相当的麦克风用于手机。强大、稳定和微型麦克风的可用性将改善现有的HA系统，并促进利用多个麦克风进行定向感测和噪声消除的新HA系统的开发。NIH SBIR的目标是构建这些麦克风原型，这些原型将作为助听器行业改进麦克风的基础。

DESCRIPTION (provided by applicant): Roughly 30 million Americans suffer from hearing loss and would benefit from some form of hearing augmentation. However, the hearing aid (HA) adoption rate is low, less than 25% [Kochkin, (2009)] and those who do adopt wait more than 10 years before doing so [Donahue, (2010)]. There are a variety of reasons for the low utilization rate and long delay in adopting HAs including effectiveness, price, comfort, size, and cosmetic issues. Clearly there is a need to improve HAs so that those who suffer from hearing impairment can be more effectively helped to improve their quality of life and productivity through better treatment. In this proposal, the development of a new microphone for HA applications is sought as one avenue to improve HA effectiveness and increase utilization. In particular, development of the first piezoelectric, micro-electromechanical system (MEMS) microphones that satisfy the stringent acoustical specifications of the hearing aid industry will be undertaken. The three specific aims of the grant are to (1) design and fabricate the MEMS piezoelectric transducer element, (2) design and fabricate the amplifying electronics for readout of the transducer's electrical signal, and (3) design an appropriate housing for the mechanical and electrical elements that meets the requirements for HA applications. Compared to the existing electret condenser microphone (ECM) based technology that has dominated the field for many years, the new microphone will: be more robust to the external environment, stable over time, ease hearing aid assembly, and deliver superior acoustic performance at a smaller size. Because the MEMS fabrication applied to create this device is based on the same processes used in the semiconductor industry, once the design of these devices is perfected they can be made at low cost and easily integrated with processing electronics. Our ultimate goal is to develop a microphone that provides better acoustic performance than present HAs at a cost comparable to microphones used for cell phones. The availability of robust, stable, and miniature microphones will improve existing and facilitate the development of new HA systems that utilize multiple microphones for directional sensing and noise cancellation. The goal of this NIH SBIR is to build these microphone prototypes, which will serve as the basis for improved microphones for the hearing aid industry.