Within and Between Channel Representation

描述（由申请人提供）：本提案构成了一个心理物理实验项目，旨在研究健康人类听觉系统中听觉处理的两个方面：(a)跨频率信息的不确定性驱动整合，以及(b)观察者检测和/或分离嵌入在干扰物背景中的目标信号的能力。本文提出的实验分别考察了跨频率信息的集成以及跨时间和频率信息的集成。第一个实验序列的主要目标是比较刺激不确定性的影响，在这些任务中，观察者应该从单个频率位点提取频率，而不是比较整个频谱的信息。对于前一项任务，有人认为观察者不能选择性地关注单个频率轨迹，这一解释很难与后一项任务的不确定性效应相协调。第二组研究提供了不同线索对声源分离的相对功效的估计。实验检验了多个线索是独立表征和最佳组合的假设。此外，实验估计了两个源分离成“听觉流”后的频率选择性。提出的实验通过分析阈值数据和检查时间和频率的相对权重来解决这些问题。与信号检测理论相关的处理模型构成了数据分析的基础。实验观察者为听力图正常的本科生，实验方法可用于测试听力受损的人，即多源存在导致大量掩蔽的人。

DESCRIPTION (provided by applicant): This proposal constitutes a psychophysical experimental program which examines two aspects of auditory processing in the healthy human auditory system: (a) uncertainty-driven integration of information across frequency, and (b) observers' ability to detect and/or segregate target signals embedded in a background of distracters. The proposed experiments examine the integration of information across frequency and the integration of information across time and frequency, respectively. The primary goal of the first sequence of experiments is to compare effects of stimulus uncertainty using tasks in which observers should extract frequency from a single frequency locus vs. compare information across the spectrum. For the former task it has been suggested that observers fail to selectively attend to a single frequency locus, an explanation that is difficult to reconcile with uncertainty effects for the latter task. The second set of studies provides estimates of the relative efficacy of different cues for sound source segregation. The experiments examine the hypothesis that the multiple cues are independently represented and optimally combined. In addition, the experiments estimate frequency selectivity after the segregation of two sources into "auditory streams." The proposed experiments address these issues by analyzing threshold data and examining relative weights in time and frequency. Processing models associated with signal detection theory form the basis of data analysis. While the experimental observers are undergraduates with normal audiograms, the experimental methods can be adopted to test persons suffering hearing impairment, persons for whom the presence of multiple sources leads to substantial masking.