MECHANISMS OF ACOUSTIC PERCEPTION AND ORIENTATION

将采用行为、生理和解剖学方法， 研究多普勒频移补偿蝙蝠生物声纳系统， [医]斑背蕨 将在动物中分析回声行为 追求和捕捉猎物，并在模拟（钟摆）飞行。 注意力将被引导到振幅以及多普勒频移 补偿和分析基本信号参数（CF、FM 和谐波）在不同的回声定位情况下变化。 计算机 辅助分析将用于研究变化的信号参数， 麦克风以及耳蜗微音器电位记录， 长期植入电极和微型无线电遥测 系统 这些数据将用于评估现有的理论， 回声定位，以建立耳朵的响应特性， 实际的回声反射条件，并获得有关复杂的知识， 耳朵通常遇到的刺激条件的类型。 的 耳蜗的结构，尤其是与 机械振动，精细的频率分析和不寻常的共振 耳朵的特性将通过光和扫描进行研究， 透射电子显微镜 定量数据将从 连续切片以评估不同组织中的形态学特性， 并将不同区域中的结构相关联 耳蜗的频率图。 这一长期目标的主要目标是 研究生物声纳信号设计和信号处理， 并展示了一些方法， 哺乳动物的耳蜗已经被修改以满足不寻常的感觉需求。 实验将被设计成表明在受体水平上的微调 通过改变振动元件的布置 和/或其感觉过程，或通过机械或 生化支持系统 这项研究的信息将是 有助于理解许多基本的生物声学现象， 声学信号处理领域的技术进步， 无线电遥测 了解这些系统的基本机制， 证明对进一步发展盲人导航设备是有用的 以及用于声学成像。

Behavioral, physiological and anatomical methods will be employed to investigate the biosonar system of the Doppler-shift compensating bat, Pteronotus p. parnellii. Echolocative behavior will be analyzed in animals pursuing and capturing prey and during simulated (pendulum) flight. Attention will be directed to amplitude as well as Doppler-shift compensation and to analysis of the ways basic signal parameters (CF, FM and harmonics) change in different echolocative situations. Computer assisted analysis will be utilized to study changing signal parameters in microphone as well as cochlear microphonic potential records obtained with chronically implanted electrodes and with a microminiature radiotelemetry system. These data will be used to assess existing theories of echolocation, to establish the response characteristics of the ear under actual echolocative conditions and to gain knowledge about the complex types of stimulus conditions that the ear normally encounters. The structure of the cochlea, and especially elements associated with mechanical vibrations, fine frequency analysis and the unusual resonance properties of the ear will be studied with light and scanning and transmission electron microscopy. Quantitative data will be obtained from serial sections in order to assess morphologic properties in different regions of the cochlea and to correlate structures in different regions with frequency maps of the cochlea. The major long term goals of this investigation are to study biosonar signal design and signal processing at peripheral and central levels and to demonstrate some of the ways in which the mammalian cochlea has been modified to meet unusual sensory demands. Experiments will be designed to show that fine tuning at the receptor level has been accomplished by changing the arrangement of the vibratory elements and/or their sensory processes, or through changes in mechanical or biochemical support systems. The information from this study will be useful for understanding many basic bioacoustic phenomena and for technological advances in the areas of acoustic signal processing and radiotelemetry. Knowledge of the mechanisms underlying these systems may prove useful in the further development of navigational aids for the blind and for acoustic imaging.