Optimizing bilateral and single-sided-deafness cochlear implants for functioning in complex auditory environments

摘要：本研究旨在优化人工耳蜗人的言语理解和空间听觉效果。 植入(CI)用户，特别是双侧(BI-CI)和单侧耳聋(SSD-CI)用户。知识的鸿沟 目前尚不清楚是什么导致对侧干扰，它如何影响言语理解和双耳 好处，以及如何补救。我们研究计划的长期目标是优化听力 具有两个输入的CI用户的性能。本应用程序的总体目标是确定机制 不对称的潜在功能后果，特别是通过两种表现形式的现象 对侧干扰：“双侧言语干扰”(一只耳朵出现的言语妨碍了在- 站在另一边，通常是较好的耳朵干扰较差的耳朵)和“耳间响度不匹配”(双耳 在呈现时同样响亮的横向刺激在呈现时顺序地产生失真的空间地图 同时)。我们最主要的功能假设是不对称的听力，表现在对侧 干扰，是阻碍现实世界CI性能的主要因素。我们最重要的机械论假设是 这两种现象源于不对称的外周失真或中枢听觉适应不良可塑性，或两者兼而有之。 我们将通过三个具体目标来检验我们的总体假设：(1)衡量反制的后果-- 耳间不对称造成的侧向干扰(双侧语音干扰和耳间响度不匹配) 日益现实的情况；(2)确定外围不对称在多大程度上解释对侧 (3)确定对侧干扰是否受中枢听觉可塑性的影响。这些目标将 产生以下预期结果：(1)确定BI-CI和 SSD-CI空间听力结果受到对侧干扰的限制；(2)扩展客观技术-Pre-Pre VIEW用于了解单耳CI的表现--以表征周围神经功能之间的联系 活体和双耳加工；(3)确定异常的跨耳加工是否对中枢可塑性敏感。 这一贡献是显著的，因为从两个不对称现象来看，对侧干扰 双侧语音干扰和耳间响度不匹配是双耳听力良好的主要障碍。 了解对侧干扰的原因和负面后果将提供优化工具 为30-50%的BI-CI和近100%的听力不对称的SSD-CI使用者提供康复。这项工作是 创新是因为(1)它试图理解基于不对称效应的听力结果中的障碍， 它不是单独优化每个EAR，(2)它比较BI-CI和SSD-CI用户以区分机制- 对侧干扰背后的神经系统，以及(3)它配对区分BE-BE的感知和客观措施。 在不对称病例中，外周和中枢之间对听力结果差的影响。

ABSTRACT: This research aims to optimize speech-understanding and spatial-hearing outcomes for cochlear- implant (CI) users, specifically bilateral (BI-CI) and single-sided-deafness (SSD-CI) users. The gap in knowledge is that it is unknown what causes contralateral disruption, how it affects speech understanding and binaural benefits, and how it might be remediated. The long-term goal of our research program is to optimize hearing performance for CI users with two inputs. The overall objective of this application is to determine the mechanisms underlying functional consequences of asymmetry, specifically through two phenomena that are manifestations of contralateral disruption: “bilateral speech interference” (speech presented in one ear impedes speech under- standing in the other, usually the better ear interfering with the poorer) and “interaural loudness mismatch” (bi- lateral stimuli that are equally loud when presented sequentially produce a distorted spatial map when presented simultaneously). Our overarching functional hypothesis is that asymmetric hearing, manifesting in contralateral disruption, is a major factor stunting real-world CI performance. Our overarching mechanistic hypothesis is that the two phenomena stem from asymmetric peripheral distortion, central auditory maladaptive plasticity, or both. We will test our overarching hypotheses through three specific aims: (1) Measure the consequences of contra- lateral disruption (bilateral speech interference and interaural loudness mismatch) from interaural asymmetry for increasingly realistic situations; (2) Determine the extent to which peripheral asymmetry explains contralateral disruption; (3) Determine if contralateral disruption is influenced by central auditory plasticity. These aims will yield the following expected outcomes: (1) identify the situations, prevalence, and magnitude where BI-CI and SSD-CI spatial-hearing outcomes are limited by contralateral disruption; (2) extend objective techniques—pre- viously applied to understand monaural CI performance—to characterize the link between peripheral neural sur- vival and binaural processing; (3) determine if abnormal across-ear processing is susceptible to central plasticity. This contribution is significant because contralateral disruption, viewed through the two asymmetry phenomena of bilateral speech interference and interaural loudness mismatch, is a major roadblock to good binaural hearing. Understanding the causes and negative consequences of contralateral disruption will provide tools to optimize rehabilitation for the 30-50% of BI-CI and nearly 100% of SSD-CI users with asymmetric hearing. The work is innovative because (1) it seeks to understand the roadblock in hearing outcomes based on asymmetry effects, rather than optimizing each ear individually, (2) it compares BI-CI and SSD-CI users to distinguish the mecha- nisms underlying contralateral disruption, and (3) it pairs perceptual and objective measures to differentiate be- tween peripheral and central contributions to poor hearing outcomes in asymmetric cases.