Bilateral cochlear implants: improving performance

描述(由申请人提供)：正常听力是双耳的，与单耳听力相比具有显著的优势。有两只耳朵的听众能够更准确地定位声源，并在空间上分离的、相互竞争的声源存在的情况下更准确地理解说话者。这些优势是双侧人工耳蜗术的主要动机。在这项应用中，人工耳蜗植入和双耳听力方面的专家共同努力，以更好地了解与当今限制性能的双边声音处理策略相关的因素，并设计、实施和测试将这些限制降至最低的新声音处理策略。五名双侧植入的受试者将通过心理物理研究来深入研究他们对单耳和多耳电极对耳间时间差(ITD)和耳间电平差(ILD)的基本敏感性。这些敏感性将与三种新的双边刺激方法进行比较。这些新方法在一定程度上提高了在耳间电极对水平上测量的耳间灵敏度，我们建议将它们纳入语音处理策略，以确定它们是否改善了急性测试中的功能表现。由于今天的声音处理策略限制了受试者获得单个电极上可用的耳间敏感性，我们还建议实施并敏锐地评估两种旨在克服这些限制的语音处理策略。那些在功能测试中表现出希望的语音处理策略将被用于纵向测试，以评估渐近性能和学习。

DESCRIPTION (provided by applicant): Normal hearing is binaural and provides significant advantages over monaural listening. Listeners with two ears are able to more accurately localize sound sources and more accurately understand a talker in the presence of spatially-separated, competing sound-sources. These advantages are a primary motivation for bilateral cochlear implantation. In this application, experts in cochlear implants and binaural hearing join in an effort to better understand the factors associated with today's bilateral sound-processing strategies that limit performance and to design, implement and test new sound-processing strategies that minimize those limitations. Five bilaterally-implanted subjects will be studied in depth using psychophysical studies to characterize their basic bilateral sensitivity to interaural time difference (ITD) and interaural level difference (ILD) using single and multiple interaural-electrode pairs. These sensitivities will be compared to those of three new methods of bilateral stimulation. To the extent these new methods improve the interaural sensitivity as measured at the level of interaural-electrode pairs, we propose to incorporate them in speechprocessing strategies to determine whether they improve functional performance in acute testing. Because today's sound-processing strategies limit a subject's access to the interaural sensitivity available at the individual electrodes, we also propose to implement and acutely evaluate two speech-processing strategies designed to overcome these limitations. Those speech-processing strategies that show promise in functional testing will be implemented for longitudinal testing to assess asymptotic performance and learning.