Optimized Conditioned Processing for Cochlear Implants

目前，相当大比例的现代人可以在安静的环境中获得高水平的言语感知 Cdchlear植入者。然而，在噪声背景中，尤其是当噪声是竞争语音时， 言语知觉严重受损。一种在噪声中改善语音感知的可能方法 是为了改善电刺激听觉放电模式中语音的时间表征 神经纤维。这种方法也有望改善双侧种植体的性能。 受试者的任务需要对耳间时间进行脑干分析。详细的生物物理模型和 动物研究表明，改进的时间表征可以通过 使用“条件性刺激”--一系列未调制的高频率脉冲，使听觉活动失去同步性 神经元对相互竞争的信号的反应。这一过程的使用极大地提高了人们的言语感知能力 在一些受试者中表现为安静和/或噪音，而在其他受试者中则不然。拟议工作的目标是优化 语音信号和调节器两者的呈现，以便在安静的情况下最大化语音感知 和噪声，以及改善基于时间的偏侧化的感知 双侧植入物的双耳暴露。因为时间音调机制需要准确 如果信息要有用，那么音调就被认为对比赛中的言语辨别至关重要 语音、滤波器到电极的映射将在有条件的语音处理器中进行处理，以最大限度地 对受试者在稳态噪声、“嘟嘟声”、时间调制噪声中的性能进行测试，例如 以及关于语音状噪音中的提示句。结果将允许对条件化的 用于单侧和双侧人工耳蜗植入者的处理器。在那些双侧种植受者中 对生理范围内的电刺激有耳间时序知觉，这项工作有可能 提供比目前更多的临床语音处理器带来的额外双耳优势 可通过耳间幅度差异获得。在单侧植入物中，这项工作已经证明 在有限的科目中获得巨大的利益；我们的目标是将这些好处传递到更广泛的领域 植入物接受者的数量。

High levels of speech perception in quiet are currently available to a significant percentage of modern cdchlear implant recipients. In a noisy background, however, particularly if that noise is competing speech, speech perception is dramatically impaired. One possible method for improving speech perception in noise is to improve the temporal representation of speech in discharge patterns of electrically stimulated auditory nerve fibers. This method would also be expected to improve the performance of bilateral implant recipients on tasks requiring brainstem analysis of interaural timing. Detailed biophysical models and animal studies have demonstrated that improved temporal representation can be accomplished through the use of "conditioning stimuli" - trains of unmodulated high-rate pulses that desynchronize activity of auditory neurons to competing signals. Use of this procedure has led to dramatically increased speech perception in quiet and/or noise in some subjects, but not in others. The goal of the proposed work is to optimize the presentation of both the speech signal and the conditioner so as to maximize speech perception in quiet and noise for unilateral implant recipients, as well as improve perception of temporally-based lateralization and binaural unmasking in bilateral implantees. Because temporal pitch mechanisms demand accurate place information if they are to be useful, and pitch is thought critical for speech discrimination in competing speech, filter-to-electrode mappings will be manipulated in conditioned speech processors to maximize performance on a test of spondees in steady-state noise, "babble noise", temporally modulated noise, as well as on HINT sentences in speech-shaped noise. The results will allow optimization of conditioned processors for unilateral and bilateral cochlear implant recipients. In those bilateral implant recipients who have interaural timing perception for electrical stimuli in the physiologic range, this work has the potential to provide significant additional binaural benefits from a clinical speech processor beyond those currently available via interaural amplitude differences. In unilateral implantees, this work has already demonstrated substantial benefit in a limited number of subjects; it is our goal to deliver these benefits to the broader population of implant recipients.