Optimized Conditioned Processing for Cochlear Implants

描述（由申请人提供）：目前，相当大比例的现代人工耳蜗植入者在安静环境中可获得高水平的言语感知。然而，在嘈杂的背景下，特别是如果噪声是竞争语音，语音感知会受到严重损害。改善噪声中语音感知的一种可能方法是改善电刺激听觉神经纤维放电模式中语音的时间表示。这种方法也有望改善双侧植入受体在需要进行脑干分析的任务中的表现。详细的生物物理模型和动物研究表明，改善的时间表示可以通过使用“条件刺激”来实现-未调制的高速率脉冲，使听觉神经元的活动与竞争信号无关。使用这种程序已导致在安静和/或噪声中的一些受试者的言语感知显著增加，但在其他受试者中则不然。所提出的工作的目标是优化语音信号和调节器的呈现，以便最大限度地提高单侧植入物接受者在安静和噪声中的语音感知，以及改善双侧受试者基于时间的偏侧化和双耳解蔽的感知。由于时间音高机制需要准确的位置信息，如果他们是有用的，和音高被认为是关键的语音歧视在竞争的语音，过滤器到电极的映射将被操纵在有条件的语音处理器，以最大限度地提高性能的测试的spondees在稳态噪声，“串音噪声”，时间调制噪声，以及在语音形状的噪声的提示语句。结果将允许优化的条件处理器的单侧和双侧人工耳蜗植入受体。在那些双侧植入受体谁有耳间的时间感知电刺激的生理范围内，这项工作有可能提供显着的额外双耳的好处，从临床语音处理器超出目前可通过耳间振幅差。在单侧受试者中，这项工作已经在有限数量的受试者中证明了实质性的益处;我们的目标是将这些益处提供给更广泛的植入受体人群。

DESCRIPTION (provided by applicant): High levels of speech perception in quiet are currently available to a significant percentage of modern cochlear 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.