Sound Source Segregation and Determination

描述(由申请人提供)：人类听觉的最重要特征是那些促进声学特征分离和整合的特征，从而导致确定实际声源。由于环境通常包括多个同时存在的物体，因此听觉系统必须从根本上起到“分离机器”的作用，它的工作是从到达耳朵的复杂的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力的一项重要功能。我们在这里提出，这些功能也是脊椎动物一般听觉的原始特征，并且这些功能在脊椎动物听觉系统的整个进化过程中最重要的是定义了成功和适应性。总体目标是确定脊椎动物听觉的这些原始功能在相对简单的脊椎动物物种中是如何运作的。一个目标是帮助建立一个生物学和进化的背景，在这个背景下，人类的听力可以得到更充分的理解。目的1：我们将调查一个简单的脊椎动物物种在存在多个同时存在的声源(即听觉场景分析和源分离)时确定源特征的能力。我们将研究其他促进人类听者听觉感知分离的声学特征，以了解它们对鱼类听者的影响。这些特征包括起始异步性、调幅、持续时间、调和结构(以及空间起源：目标2)。这些特征将通过使用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声源来研究听觉声源分离。我们将独立于可能在声源分割中起作用的非空间声学特征(目标1)来分析声源的空间起源的影响。目的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来源的反应来确定支持来源分离的神经编码和表征的性质。我们将重点了解大脑在分离和整合来自一个或多个来源的同时声学成分时可以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.