CHANNEL INTERACTION IN COCHLEAR IMPLANTS

描述（由申请人提供）：多通道人工耳蜗（CIs）被设计为通过刺激耳蜗内的不同部位向受体提供特定频率的信息。然而，耳蜗内多个刺激部位的存在增加了这些部位之间相互作用的风险。通道相互作用是当CI中的电极刺激重叠的神经群时发生的一种现象。当多个电极同时受到刺激时，来自每个电极的电流场可以在神经刺激之前相加或相减。感知结果可能是一种令人不舒服的大声或听不到的刺激。当两个电极快速连续受到刺激时，神经纤维对第一个电极的反应变得难以反应，因此无法对第二个电极作出反应。因此，语音信号中的一些信息可能没有被听觉外围区充分编码，这可能会对CI的语音感知性能产生负面影响。先前的研究表明，通道相互作用可以从心理生理和生理两方面进行测量，但人们对这两种测量方法的关联程度知之甚少。通道相互作用的心理物理测量可能有助于为个体CI接收者创建最佳语音处理器程序。不幸的是，进行详细的心理物理测量在临床上是不可行的，因为这是耗时的，而且通常不可能用于儿科CI接受者。然而，通道相互作用的外围测量可以通过生理学技术相对较快地完成。本应用程序的总体目标是确定通道相互作用的生理测量与通道相互作用的心理物理测量之间的关系，以及这些测量中的任何一种是否可以帮助临床医生为个体CI接受者选择最佳的语音处理参数。本实验旨在：(1)研究非同步刺激下通道相互作用的生理和心理测量之间的关系；(2)探讨同时刺激下通道相互作用的生理和心理生理指标之间的关系；(3)利用同时刺激和非同时刺激的语音处理策略，研究通道交互与语音感知性能之间的关系。

DESCRIPTION (provided by applicant): Multi-channel cochlear implants (CIs) are designed to provide frequency-specific information to the recipient by stimulating different sites within the cochlea. However, the presence of multiple stimulation sites within the cochlea increases the risk of interaction between these sites. Channel interaction is a phenomenon that can occur when electrodes in a CI stimulate overlapping neural populations. When multiple electrodes are stimulated simultaneously, current fields from each electrode can sum or subtract prior to neural stimulation. The perceptual result can be a stimulus that is either uncomfortably loud or inaudible. When 2 electrodes are stimulated in rapid succession, nerve fibers become refractory in response to the first electrode and are thus unable to respond to the second electrode. As a result, some information in the speech signal may not be adequately encoded by the auditory periphery, which might have negative effects on speech perception performance with the CI. Previous research has shown that channel interaction can be measured both psychophysically and physiologically, but little is known about the extent to which these 2 measures are related. Psychophysical measures of channel interaction may be useful for making decisions about creating optimal speech processor programs for individual CI recipients. Unfortunately, making detailed psychophysical measures is not clinically feasible because it is time consuming and generally not possible with pediatric CI recipients. However, peripheral measures of channel interaction can be made relatively quickly with physiologic techniques. The overall goal of this application is to determine how physiologic measures of channel interaction are related to psychophysical measures of channel interaction, and if either of these measures can aid the clinician in choosing optimal speech processing parameters for individual CI recipients. The proposed experiments are designed to: (1) investigate the relation between physiologic and psychophysical measures of channel interaction for non-simultaneous stimulation; (2) investigate the relation between physiologic and psychophysical measures of channel interaction for simultaneous stimulation; and (3) investigate the relation between channel interaction and speech perception performance using speech processing strategies that employ both simultaneous and non-simultaneous stimulation modes.