Developmental Studies of Sound Localization Mechanisms

声音定位机制的发展研究

• 批准号: 7250871
• 负责人: Daniel J Tollin
• 金额: $ 20.95万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7250871
• 关键词: Acoustics; Adult; Age; Animals; Auditory; Brain Stem; Caliber; Cell Nucleus; Cells; Cephalometry; Cochlear Implants; Code; Complex; Computer Simulation; Condition; Contralateral; Cues; Data; Development; Dimensions; Ear; External Ear; Felis catus; Frequencies; Goals; Growth; Head; Hearing; Hearing Aids; Lateral; Lead; Location; Measures; Medial; Methods; Modeling; Neurons; Olives - dietary; Pathway interactions; Pattern; Peripheral; Population; Process; Property; Prosthesis; Range; Relative (related person); Shapes; Site; Sound Localization; Source; Staging; Stimulus; Structure; System; Techniques; Testing; Time; Week; Weight; age group; aged; base; binaural hearing; design; external ear auricle; ilium; neural circuit; neuromechanism; postnatal; relating to nervous system; research study; response; size; sound; trapezoid body; virtual

DESCRIPTION (provided by applicant): The goals of this project are to understand the concurrent development of the acoustical cues to sound source location and the neural circuits that encode them. All cues for localization can be captured in measurements of head related directional transfer functions (DTFs), which contain the three main cues, interaural differences in time (ITDs) and level (ILDs) and monaural spectral shape cues. Since the formation of these cues is governed by the linear dimensions of the head and pinnae, the relative magnitudes of the cues will change as these structures grow. These experiments test the hypothesis that during the development of one of the cues, ILD, there is a concomitant development of the ability of cells in the lateral superior olive (LSO), one of the most peripheral sites for binaural interaction, to encode ILDs. Aim I will test the hypothesis that the cues will change in ways predictable from the increasing dimensions of the head and pinnae. DTFs will be measured in kittens aged from 1 week to adult and the cues to location extracted from them. The cues will be compared to measurements of the head and pinnae. Aim II will test the hypothesis that the range of ILDs encoded by LSO cells will increase during development with the expected increase in the magnitudes of the physical ILDs, as measured in Aim I. Also, the ability of cells in the medial nucleus of the trapezoid body, which provide the contralateral inhibitory input to the LSO, to encode the complex spectral shapes necessary for ILD computation will be studied. These studies will determine if and how long these nuclei in the ascending binaural system can compensate for changes in the cues brought about by developmental changes in the acoustical properties of the head and pinnae. Finally, Aim III will study the normal mechanisms by which the cues to location, in particular those based on spectral shape (ILDs and monaural spectral cues), are encoded by the LSO and its afferents in adult cats. Several techniques, including virtual space stimulation and a systems identification method, will be used in Aims II and II1. We hypothesize that across a population of inputs to the LSO, complex spectral shape is represented and that the LSO computes a spectral difference to extract the ILD from these inputs. A better understanding of how complex sound spectra are represented will lead to better designs for the processing strategies in auditory prosthetics like cochlear implants and hearing aids.

描述（由申请人提供）：该项目的目标是了解声音提示与声音源位置以及编码它们的神经回路的并发开发。所有线索都可以捕获在头部相关定向函数（DTF）的测量中，该函数包含三个主要提示，时间（ITD）和水平（ILD）和单声频谱形状提示。由于这些提示的形成受头部和小针的线性尺寸的控制，因此提示的相对大小会随着这些结构的增长而发生变化。这些实验检验了以下假设：在一个提示的发展过程中，ILD的一个提示过程中，细胞在侧向上橄榄（LSO）中的能力伴随发展，这是双耳相互作用的最外围外围部位之一，用于编码ILD。目的我将检验以下假设：提示将从头部和小耳的增加的尺寸增加的方式变化。 DTF将在年龄从1周到成人的小猫中测量，并从中提取的位置进行测量。提示将与头部和小针的测量值进行比较。 AIM II将检验以下假设：在发育过程中，LSO细胞编码的ILD范围将增加，而预期的是物理ILD的幅度的预期增加，如AIM I中所测量的。此外，梯叶体内侧核中细胞的能力，可为与LSO相对的抑制输入，以编码复杂的光谱层次，以便于配置构造相对的抑制作用。这些研究将确定上升双耳系统中的这些核是否以及多长时间可以补偿由头部和小针的声学特性变化带来的线索变化。最后，AIM III将研究正常机制，该机制通过LSO及其在成年猫中的传入来编码的位置提示，特别是基于光谱形状的线索（尤其是基于光谱形状的线索）。 AIMS II和II1将使用几种包括虚拟空间刺激和系统识别方法在内的技术。我们假设在LSO的一系列输入中，复杂的光谱形状被表示，LSO计算了光谱差异以从这些输入中提取ILD。更好地理解对复杂的音频的代表方式，将为耳蜗植入物和助听器等听觉假肢中的处理策略提供更好的设计。