Acoustic Behavior - Neural and Comparative Bases

描述（由申请人提供）：本实验室的长期目标是了解生物力学、解剖学和生理学如何使听力具有高灵敏度和方向敏锐度。该建议专注于微尺度耳朵，因为物理约束使得声音定位和高灵敏度对于微尺度尺寸的耳朵来说非常具有挑战性。蚊子是最小的能听到声音的动物之一。它们拥有附在约翰斯顿的听觉器官（JO）上的触角，作为它们头部的外部附属物。JO在功能上类似于哺乳动物的耳蜗，但更容易接近。这项工作将使用多普勒激光测振仪来测量机械响应和生理记录，以测试两个天线的灵敏度。初步数据显示，这些耳朵对大带宽的声音敏感，振动模式与之前公布的有很大不同。这些数据将导致天线振动的数学模型。初步计算已经表明，天线的噪声特性可能比鼓膜的噪声特性好上级。伊蚊并不是最小的能听到声音的昆虫。有趣的是，更小的摇蚊和更大的蚊子的触角大小都差不多。这表明它们都接近声学功能的尺寸下限。比较这三个物种的耳朵可能会揭示听觉功能的局限性。JO的超过30，000个感觉细胞具有独特且高度有序的结构，这表明音调组织和模态分离使得性能等同于宏观耳朵。苔藓的触角对重力和风以及声音都有反应。触角的基本结构和功能将用分子标记物探测，以确定其机械感觉神经元之间的功能细分。这项研究与公共卫生和NIDCD的使命有关。远场粒子速度和触角耳朵是小尺寸听觉声学中相对未探索的领域。这项工作的一个目标是揭示所有大小尺度下听觉功能背后的基本原理。小型化是实际工程中追求的目标。这些微型耳朵的设计特征可以激励机械工程师进行仿生并将它们“转化”为新型的纳米到微米级定向麦克风。这些发现可能远远超出了昆虫学的好奇心。 公共卫生相关性：该项目研究已知最小耳朵的听力，最终目标是提供工程师可能用于开发改进助听器的小型定向麦克风的信息。

DESCRIPTION (provided by applicant): The long-term goal of this laboratory is to understand how biomechanics, anatomy, and physiology enable hearing of high sensitivity and directional acuity. This proposal focuses on microscale ears because physical constraints make sound localization and high sensitivity extraordinarily challenging with ears of microscale dimension. Mosquitoes are among the smallest animals that hear. They possess antennae attached to Johnston's hearing organs (JOs) as external appendages on their heads. JOs are functionally analogous to the mammalian cochlea, but far more accessible. This work will use Doppler laser vibrometry to measure mechanical responses and physiological recordings to test the sensitivity of the two antennae. Preliminary data show that these ears are sensitive to sound over a large bandwidth and have modes of vibration substantially different from those published before. These data will lead to a mathematical model of antennal vibration. Preliminary calculations already indicate that antennae may have noise characteristics superior to those of tympana. The Aedes mosquito is not the smallest insect that hears. Interestingly, the antennae of even tinier midges and of even larger mosquito species are all about the same size. This suggests that they are all near the lower size limit for acoustic function. Comparing ears in these three species may reveal the limits of auditory function. The over 30,000 sensory cells of the JO have a unique and highly-ordered architecture that suggest tonotopic organization and modality fractionation enabling performance equal to macroscopic ears. Mosquito antennae respond to gravity and wind as well as to sound. The basic structure and function of antennae will be probed with molecular markers to determine functional subdivisions among its mechanosensory neurons. This research is relevant to public health and the mission of NIDCD. Far-field particle velocity and antennal ears are a relatively unexplored realm of auditory acoustics at small size. A goal of this work is to reveal the basic principles behind auditory function at all size scales. Miniaturization is coveted goal in practical engineering. The design features of these miniature ears could motivate mechanical engineers to biomimic and "translate" them into novel nano-to-microscale directional microphones. These findings potentially extend well beyond mere entomological curiosity. PUBLIC HEALTH RELEVANCE: This project investigates hearing in the smallest known ears, with the ultimate goal of providing information that engineers might use to develop small directional microphones for improved hearing aids.