Comparisons of Binaural Processing at Low & High Frequencies

描述(由申请人提供)：拟议研究的目标仍然是评估、表征和比较双耳听觉系统如何处理耳间时间差异(ITD)，这是声音本地化的主要线索。研究计划直接来源于我们的发现，即使用特殊的“转置”高频刺激可以克服听者在高频通道中处理ITD的典型能力较差的问题。转置刺激不仅导致更有效的ITD处理，而且当其他低频信息存在时，它们似乎对用常规高频刺激观察到的退化效应具有相对“免疫力”。拟议的研究计划旨在揭示和了解高频时间波形包络的哪些具体方面足以增强ITD的处理能力，并对双耳“干扰”产生“抵抗”。为了提供答案，我们建议使用一种多方面的、收敛的、我们相信的创新方法，该方法利用以下各项的组合：1)许多复杂的基于计算机的技术，用于通过特定的度量来控制和量化高频刺激包络的时间特征；2)高精度和可重复的阈值-ITD和基于ITD的偏侧性的行为测量；3)一种理论方法，根据外部刺激本身的变化，或者根据听觉加工的外围和中央阶段处理的刺激的变化，产生关于行为数据模式的特定定量预测。这项拟议的研究与公共健康的相关性包括更好地理解耳朵和大脑如何处理基于包络的信息可能带来的健康益处。我们的研究结果有望为其他人提供指导，指导他们如何操纵高频波形包络的特定时间方面，以通过人工耳蜗和/或数字助听器等假体设备更有效地传递单耳和双耳计时信息。

DESCRIPTION (provided by applicant): The objectives of the proposed research continue to be an evaluation, characterization, and comparison of how the binaural auditory system processes interaural temporal disparities (ITDs), a major cue for the localization of sound. The program of research flows directly from our findings that the use of special "transposed" high-frequency stimuli can overcome the typically poor ability of listeners to process ITDs within high-frequency channels. Not only do transposed stimuli lead to more efficient ITD-processing, they also appear to be relatively "immune" to the degrading effects observed with conventional high-frequency stimuli, when other, "jamming" or "interfering," low-frequency information is present. The proposed program of research seeks to reveal and understand what specific aspects of the envelopes of high-frequency temporal waveforms are sufficient for the processing of ITDs to be enhanced and for "resistance" to binaural "interference" to occur. In order to provide answers, we propose to employ a multi-faceted, convergent, and, we believe, innovative approach that exploits the combination of 1) a number of sophisticated computer- based techniques for controlling and quantifying via specific metrics the temporal characteristics of the envelopes of high-frequency stimuli; 2) highly precise and repeatable behavioral measures of threshold-ITDs and ITD-based laterality; 3) a type of theoretical approach that yields specific quantitative predictions about the patterning of the behavioral data in terms of either variations in the external stimulus, per se, or in terms of variations in the stimuli as processed by both peripheral and central stages of auditory processing. The relevance of the proposed research to public health includes potential health benefits stemming from a better understanding of how the ear and brain process envelope-based information. The results of our investigations promise to provide direction to others about how they can manipulate specific temporal aspects of the envelopes of high-frequency waveforms to convey more efficiently monaural as well as binaural timing information via prosthetic devices such as cochlear implants and/or digital hearing aids..