SOUND SOURCE LOCALIZATION AND IDENTIFICATION BY A MODEL AUDITORY SYSTEM

我们的总体目标是确定一个简单的脊椎动物听觉系统 在听力的基本过程中的作用：检测， 声源的识别、分类和位置。在.期间 在最后一次授权期，我们证明了金鱼(Carassius Auratus) 表现得就像他们有对应于 频谱音调、虚拟音调、音色和粗糙度。此外, 生理实验表明，简单、离散的通道 外围设备的频率选择性在 将中脑的水平更精确地调整和连续分布 通过抑制合成的滤波器组阵列。抑制中的 中脑还合成了新的方向性反应模式。 这些和其他结果导致了一种假设，即生理上的 哺乳动物的听觉系统和听觉的功能 心理声学研究发现哺乳动物是原始脊椎动物 鱼类和其他非哺乳动物类群共有的特征。同时 久而久之，鱼在脊椎动物中处于极端地位 到进化史、内耳结构和外周表现 频率因此，了解鱼类的听力机制是一种 进一步评估变化规模的重要基准 以及脊椎动物作为一个类群的相似性，并建立一个 人的听觉可以更完整的生物背景 明白了。这个项目主要关注两个基本方面 脊椎动物的听觉：频谱和时间的加工 复杂的声音唤起对音高的感知，以及能力和 声源本地化的机制。互补的行为， 提出的神经生理学和建模研究将有助于识别 神经结构、编码和基础这些基本机制 脊椎动物的听觉方面。

Our overall goals are to determine how a simple vertebrate auditory system functions in the fundamental processes of hearing: the detection, identification, classification, and the location of sound sources. During the last grant period we demonstrated that goldfish (Carassius auratus) behave as if they had internal perceptual dimensions corresponding to spectral pitch, virtual pitch, timbre, and roughness. In addition, physiological experiments have revealed that the simple, discrete-channel frequency selectivity of the periphery is transformed at or prior to the level of the midbrain into more sharply-tuned and continuously distributed filterbank array that has been synthesized by inhibition. Inhibition in the midbrain has also synthesized novel directional response patterns. These and other results have led to the hypothesis that the physiological functions of the mammalian auditory system and the sense of hearing among mammals as revealed in psychoacoustical studies are primitive vertebrate characters shared by fishes and other non-mammalian taxa. At the same time, fishes represent an extreme position among vertebrates with respect to phylogeny, inner ear structure, and peripheral representations of frequency. Understanding the mechanisms of hearing among fishes is thus an important bench-mark for further evaluating the dimensions of variation and similarity among vertebrates as a group, and for establishing a biological context within which human hearing can be more completely understood. This project focuses on two fundamental aspects of the vertebrate sense of hearing: the processing to spectrally and temporally complex sounds evoking perceptions of pitch, and the abilities and mechanisms for sound source localizations. The complementary behavioral, neurophysiological, and modeling studies proposed will help identify the neural structures, codes, and mechanisms underlying these fundamental aspects of vertebrate hearing.