Using binaural beat sensitivity to describe mechanisms that may enhance binaural interactions in single-sided-deafness cochlear-implant patients

项目摘要/摘要 单侧耳聋(SSD)患者报告在理解语言和本地化方面存在严重困难 声音，尤指发自聋人一侧的声音。最近，一些SSD患者接受了一种 耳聋患者行人工耳蜗术(CI)。当前的适配策略旨在通过 通过在电极阵列上分配所有光谱信息而不考虑音调位置来单独进行CI 每个电极沿基底膜。在这项研究中，我们提出了一种新的适合患者的哲学。 利用一只听觉耳朵，从而CI映射被设计为最好地补充来自 听力正常(NH)耳。在目标1中，我们研究了双耳时间包络搏动的机制 使用带通滤波脉冲序列的NH收听者的灵敏度 使用带通滤波脉冲序列的带宽、滤波斜率和光谱重叠。我们找到了最小的 在保持检测ITD能力的同时，NH收听者可以容忍的基线ITD和光谱失配。 经验丰富的新SSD+CI监听者将完成类似的任务，结果将用于调整其 CI映射，以努力减少NH和CI耳朵之间的频率失配。在目标2中，我们将测量 噪声中的声音定位和语音理解，将性能与标准临床地图进行比较 新的实验地图基于耳朵之间更接近的光谱匹配。绩效将被衡量 随着时间的推移，确保有足够的曝光量，并留出时间进行调整。在本地化任务中，我们提出了 听者的刺激旨在区分耳间电平差异和耳间电平差异的相对贡献 SSD+CI患者的时差。在第一个噪声中语音实验中，我们将测量语音 在使用两种掩码类型的三种空间配置中的识别性能：语音形状噪声和两种掩码类型 说话者胡言乱语。通过同时使用能量(噪声)和信息性(双人交谈)掩蔽器，我们将测试 假设频率到地点映射在本地化方面的改进优于 标准的临床地图，特别是在双耳益处超出了“更好的耳朵”表现的情况下 包括信息掩饰占主导地位的复杂听力情景。这项研究的结果 将提供有关患有CI的SSD患者的双耳相互作用的新信息，并可能提供新的和 在存在相当大的残余听力的情况下，更成功地拟合CI的方法 对侧耳。

PROJECT SUMMARY/ABSTRACT Patients with single-sided deafness (SSD) report significant difficulty understanding speech and localizing sound, especially when the sounds originate on the deaf side. Recently, some SSD patients have received a cochlear implant (CI) in their deaf ear. Current fitting strategies aim to maximize speech perception through the CI alone by allocating all spectral information across the electrode array without regard to tonotopic placement of each electrode along the basilar membrane. In this study, we propose a new fitting philosophy for patients with one acoustic-hearing ear, whereby CI maps are designed to best complement information from the normal-hearing (NH) ear. In Aim 1, we investigate the mechanisms of binaural temporal-envelope beat sensitivity in NH listeners using bandpass filtered pulse trains with parameters including stimulus level, filter bandwidth, filter slope, and spectral overlap using bandpass filtered pulse trains. We find the minimum baseline ITD and spectral mismatch that NH listeners can tolerate while maintaining their ability to detect ITDs. New and experienced SSD+CI listeners will complete similar tasks and the results will be used to adjust their CI maps in an effort to reduce the frequency-mismatch between the NH and CI ear. In Aim 2, we will measure sound localization and speech understanding in noise to compare performance with the standard clinical map and the new experimental map based on a closer between-ear spectral match. Performance will be measured over time to ensure sufficient exposure and allow time for adjustment. In the localization task, we present listeners with stimuli designed to separate the relative contributions of interaural level differences and interaural time differences in SSD+CI patients. In the first speech-in-noise experiment, we will measure speech recognition performance in three spatial configurations using two masker types: speech-shaped noise and two- talker babble. By employing both energetic (noise) and informational (two-talker babble) maskers, we will test the hypothesis that improvement in localization produced by a frequency-to-place maps are superior to standard clinical maps especially in cases where the binaural benefit goes beyond “better ear” performance to encompass complex listening situations where informational masking dominates. The outcomes of this study will provide new information on binaural interactions in SSD patients with a CI, and may provide a new and more successful approach to fitting a CI in cases where considerable residual hearing exists in the contralateral ear.