Constraints on binaural sensitivity via bilateral bone conduction

项目说明 在正常听力中，声音通过鼓膜和中耳，即空气到达耳蜗处。 导通(AC)。第二种听力模式，称为骨传导(BC)，绕过传导 主要通过周围骨骼的振动引起耳蜗内压力波动的途径。而当 在正常收听条件下，BC对试听的贡献很小，BC信号很容易传递到 使用机械换能器的耳蜗和使用这种换能器的听力测试已经用于 一个多世纪来诊断传导性听力病理。对于传导性听力损失的个人，BC 使用现代BC助听器进行刺激可以改善受影响耳朵的听力(S)。BC助听器还可以 在单侧耳聋的情况下佩戴，其中聋侧的BC助听器传输信号 通过头部的骨骼和组织到达相反的(听力)耳蜗处。事实上，通过颅骨的相声是 BC刺激的一个关键特征，传统上，即使在双侧传导损失的情况下，也只有一个BC 设备已佩戴。双侧BC刺激导致两个信号在每只耳朵叠加，预计这将 限制双耳差异和相关的感知优势(声音定位、噪声中的语音感知)。 然而，在几项生物物理研究中已经报道了通过双侧耳缘的非零双耳差异，以及 与单侧BC相比，双侧BC改善了声音定位和语音噪声感知 在几项心理物理学研究中都有报道。虽然理解和开发双耳和空间听力的努力 尽管VIA BC近年来有所增加，但对业绩的基本限制仍然知之甚少。这个 目前的提案旨在填补这一知识空白。第一组实验(目标1)将量化声学 通过双侧BC装置通过测量耳壳内压传递的信息，输入驱动到 身体标本中的听觉系统。一套补充的测量将在 同时刺激AC和对侧BC，模拟呈现给单侧聋人BC的信号 助听器使用者，他们在空间任务中表现出不同的结果，但通常效果不佳。第二套 实验(目标2)将确定正常听力对双耳的心理物理敏感性的极限。 通过双边BC传递的信息跨越关键刺激参数，包括频率、带宽和 空间提示类型。日常空间任务中BC性能的额外测量，包括声音 定位和噪声中的语音感知，将完成与耳内相关的基础和 心理物理数据。总的来说，拟议的实验将评估以下主要假设：(1) BC信号在耳蜗内的叠加(E)产生系统的空间提示，并且(2)这样的提示可以 用来系统地调节知觉。数据将提供对制约因素的关键新见解 通过BC的空间听力，并指出了BC助听器技术和结果的改进策略。

Project Description In normal hearing, sound reaches the cochlea via the tympanic membrane and middle ear, i.e. air conduction (AC). A secondary mode of hearing, known as bone conduction (BC), bypasses the conductive pathway to cause pressure fluctuations within the cochlea primarily via vibration of surrounding bone. While the contributions of BC to audition under normal listening conditions are minimal, BC signals are readily passed to the cochlea using mechanical transducers, and hearing tests employing such transducers have been used for over a century to diagnose conductive hearing pathologies. For individuals with conductive hearing loss, BC stimulation via modern BC hearing aids can improve audibility in the affected ear(s). BC hearing aids may also be worn in cases of single-sided deafness, wherein a BC hearing aid on the deaf side transmits the signal through the bones and tissues of the head to the opposite (hearing) cochlea. Indeed, transcranial cross-talk is a key feature of BC stimulation, and traditionally even in cases of bilateral conductive loss, only a single BC device is worn. Bilateral BC stimulation results in superposition of two signals at each ear, which is expected to limit binaural disparities and associated perceptual benefits (sound localization, speech-in-noise perception). However, non-zero binaural disparities via bilateral BC have been reported in several biophysical studies, and improved sound localization and speech-in-noise perception with bilateral versus unilateral BC have been reported in several psychophysical studies. While efforts to understand and exploit binaural and spatial hearing via BC have thus increased in recent years, basic constraints on performance remain poorly understood. The current proposal aims to fill this knowledge gap. A first set of experiments (Aim 1) will quantify acoustic information conveyed via bilateral BC devices using measurements of intracochlear pressure, the input drive to the auditory system, in cadaveric specimens. A complementary set of measurements will be made during simultaneous AC and contralateral BC stimulation, simulating the signal presented to single-sided deaf BC hearing aid users, who show variable but generally poor outcomes in spatial tasks. A second set of experiments (Aim 2) will determine the limits of normal-hearing psychophysical sensitivity to binaural information conveyed via bilateral BC across key stimulus parameters, including frequency, bandwidth, and spatial cue type. Additional measurements of BC performance in everyday spatial tasks, including sound localization and speech-in-noise perception, will be completed and related to intracochlear and basic psychophysical data. Collectively, the proposed experiments will evaluate the overarching hypotheses that (1) BC signal superposition within the cochlea(e) generates systematic spatial cues, and that (2) such cues can be used to systematically modulate perception. Data will provide critical new insight on factors that constrain spatial hearing via BC, and point to strategies for improvement of BC hearing aid technology and outcomes.