Co-located Earphone/Microphone for Active Noise Reduction

描述(由申请人提供)：该项目的目标是设计、制造和测试用于入耳式有源降噪(ANR)系统的共置耳机/麦克风。我们的创新基于微机械薄膜，它既是麦克风的传感元件，又是耳机的致动表面。通过配置耳机和麦克风，我们的设备消除了ANR传感器和执行器之间的声波相位延迟，从而使反馈算法能够在比单独设备更高的频率下获得更高的增益。目前的听力保护设计在耳朵处提供了大约30分贝的衰减。这种保护水平不足以在许多工业噪声环境中长期暴露(可能超过130分贝)，同时将耳边的声级保持在规定的安全限值内。为了保持目前的NIOSH和OSHA噪声暴露标准，需要新的技术来保护个人免受长期暴露于有害噪声水平的影响，这些噪声水平可能会导致暂时性或永久性的听力阈值偏移。在第一阶段项目中，我们通过制造和测试原型器件证明了我们创新的可行性。我们所获得的结果显示了我们麦克风设计的敏感度，展示了我们耳机设计的发声能力，为第二阶段共置耳机/麦克风的制造提供了制造方案，并展示了在300 Hz 8000 Hz的频率范围内的降噪能力。公共健康相关性噪音导致的听力损失被美国国家职业安全与健康研究所列为影响美国个人的十大工作相关问题之一。该项目的目标是开发用于耳内通信和听力保护设备的新技术，这些设备将在比目前可能的更宽的频率范围内具有更强的听力保护能力。

DESCRIPTION (provided by applicant): The objective of this project is to design, fabricate, and test co-located earphones/microphones for use in in- ear, active noise reduction (ANR) systems. Our innovation is based on a micromachined membrane that serves as both the sensing element for a microphone and simultaneously the actuation surface for the earphone. By collocating the earphone and microphone, our device eliminates the acoustic phase delay between the ANR sensor and actuator, thereby enabling feedback algorithms with higher gain at higher frequency than is possible using separate devices. Current hearing protection designs provide approximately 30 dB of attenuation at the ear. This level of protection is not sufficient to allow long exposures in many industrial noise environments (which may exceed 130 dB) while maintaining the at-the-ear sound levels within prescribed safety limits. In order to keep within current NIOSH and OSHA noise exposure standards, new technologies are needed that will protect individuals from long-term exposure to harmful noise levels that could potentially result in temporary or permanent hearing threshold shifts. During the Phase I project, we demonstrated the feasibility of our innovation by fabricating and testing prototypical devices. The results we achieved showed the sensitivity of our microphone design, demonstrated the sound production capability of our earphone design, provided a manufacturing plan for fabrication of the co-located earphone/microphone during Phase II, and demonstrated the noise reduction capability over the frequency range of 300 Hz 8000 Hz. PUBLIC HEALTH RELEVANCE Noise-induced hearing loss ranks as one of the top 10 work-related issues by the National Institute for Occupational Safety and Health affecting individuals in the U.S. The goal of this project is to develop new technology for in-ear communications and hearing protection devices that will have greater hearing protection capability over a wider frequency range than is currently possible.