Sound Source Segregation and Determination

描述（由申请人提供）：人类听觉最重要的特征是那些促进声学特征的分离和整合，从而确定实际声源的特征。由于环境通常包括多个同时发生的物体，听觉系统的基本功能必须是一个“分离机器”，它的工作是从到达耳朵的复杂混合声源中确定单个声源。这种听觉场景分析现在被认为是人类听觉的一项重要功能。我们认为这些功能也是一般脊椎动物听觉的原始特征，并且这些功能在脊椎动物听觉系统的进化过程中最重要地定义了成功和适应。总的目标是确定这些脊椎动物听觉的原始功能是如何在一个相对简单的脊椎动物物种中运作的。其中一个目标是帮助建立一个生物和进化的背景，在这个背景下，人类的听力可以得到更充分的理解。目标1：我们将研究一种简单脊椎动物在有多个同时存在的声源时确定声源特征的能力（即听觉场景分析和声源分离）。我们将研究促进人类听者听觉感知分离的其他声学特征对鱼类听者的影响。这些特征包括起始异步、振幅调制、持续时间、谐波结构（和空间起源：目标2）。这些特征将通过刺激泛化范式的行为条件反射方法来研究它们对知觉的影响。目标2：我们将使用多个离散的局部源来研究听觉源分离。我们将分析独立于可能在声源分离中起作用的非空间声学特征（目的1）的声源空间起源的影响。目标3：我们将通过记录外周和中枢听觉神经元对上述行为实验中使用的相同信号和源的反应，确定神经编码和源分离背后的表征的本质。我们将专注于理解大脑在分离和整合来自一个或多个声源的同步声学成分时可能使用的神经活动的维度。

DESCRIPTION (provided by applicant): The most important features of the human sense of hearing are those that promote the segregation and integration of acoustic features in a way that results in the determination of actual sound sources. Since environments often include multiple and simultaneous objects, the auditory system must function fundamentally as a "separation machine" whose job it is to determine individual sources from the complex mixture of source sounds reaching the ears. This sort of auditory scene analysis is now well appreciated as an important function of human hearing. We suggest here that these functions are also primitive features of a general vertebrate sense of hearing, and that these are the functions that have defined success and fitness most importantly throughout the evolution of the vertebrate auditory system. The overall goals are to determine how these primitive functions of the vertebrate sense of hearing operate in a relatively simple vertebrate species. One goal is to help establish a biological and evolutionary context within which human hearing can be more fully understood. Aim 1: We will investigate the capacities of a simple vertebrate species to determine source characteristics when there are multiple, simultaneous sound sources present (i.e., auditory scene analysis and source segregation). We will investigate other acoustic features that promote auditory perceptual segregation in human listeners for their effects on fish listeners. These features include onset asynchrony, amplitude modulation, duration, harmonic structure, (and spatial origin: Aim 2). These features will be investigated for their effects on perception using behavioral conditioning methods using stimulus generalization paradigms. Aim 2: We will investigate auditory source segregation using multiple, discrete local sources. We will analyze the effects of the spatial origin of sources independently of the non-spatial acoustic features (Aim 1) that may play a role in sound source sesegregation. Aim 3: We will determine the nature of the neural codes and representations underlying source segregation by recording from peripheral and central auditory neurons in response to the same signals and sources used in the above behavioral experiments. We will focus on understanding the dimensions of neural activity that the brain could use in segregating and integrating simultaneous acoustic components from one or more sources.