Across-Site Patterns of Perception with Cochlear Implants

描述（由申请人提供）：我们研究的长期目标是增加听力受损患者从人工耳蜗听觉假体中获得的益处。该方法是改善定制的拟合策略，通过该策略调整听觉假体语音处理器以满足个体患者的特征。要做到这一点，我们需要了解性能缺陷的根本原因。在我们的初步研究中，我们已经表明，大多数受试者可以辨别语音识别所需的假肢刺激的基本空间和时间特征，但辨别这些特征的能力取决于刺激的参数，包括刺激电极在其电极阵列中的位置和反映在响度增长中的输入输出功能。在个体的耳蜗植入物内，性能从一个刺激部位到另一个刺激部位而变化，并且跨刺激部位的这种变化的模式是患者特异性的。这些结果表明，两种策略，优化患者的表现。一种策略是创建处理器图，该处理器图仅利用基本感知任务的性能最好的那些刺激部位。为了支持这种方法，以前的研究表明，患者可以很好地耐受刺激部位数量的减少，并且当从处理器图中删除感知较差的部位时，有时会改善性能。第二种策略是在逐部位的基础上单独优化刺激参数。例如，已知可以调节刺激水平以改善时间敏锐度。这两个策略的实施需要更好地理解人工耳蜗植入体中跨部位感知模式的基本原理。具体而言，必须解决以下问题。(1)在何种程度上是跨网站的感知模式相似的所有知觉措施？例如，导致时间感知不良的潜在条件是否也会影响空间分辨率？(2)不同的心理物理能力对语音识别的相对贡献是什么？例如，如果有必要，以牺牲空间敏锐度为代价来增强时间敏锐度是否更好？(3)空间和时间敏锐度对刺激水平有相似的依赖性吗？这些问题将通过对植入人体的心理物理学和语音识别研究来解决。这项工作将加深我们对人工耳蜗语音识别性能跨学科变化的机制的理解，并作为建立和测试临床程序以提高个体患者性能的指南。 公共卫生相关性：耳蜗植入听觉假体在恢复聋人和严重听力损失患者的沟通能力方面取得了显着的成功，但使用相同植入物和处理策略的患者之间的表现仍然存在很大的差异。我们的初步研究表明，在患者的多通道植入物中，植入物的感知因刺激部位而异，因此每个人都有优势和劣势。本申请中提出的研究将有助于阐明跨部位性能模式的一些基本特征，然后定义和测试临床拟合策略，这些策略将利用优势并可能改善数千名患者的假体听力。

DESCRIPTION (provided by applicant): The long-term objective of our research is to increase the benefit that hearing impaired patients receive from their cochlear implant auditory prostheses. The approach is to improve the custom-fitting strategy by which the auditory prosthesis speech processor is adjusted to meet the characteristics of the individual patient. To do this, we need to understand the root causes of performance deficits. In our preliminary studies we have shown that most subjects can discriminate the fundamental spatial and temporal features of prosthetic stimulation needed for speech recognition, but that the ability to discriminate these features depends on the parameters of stimulation, including the location of the stimulating electrodes within their electrode array and input-output function as reflected in loudness growth. Performance varies from one stimulation site to another within an individual's cochlear implant and the pattern of this variation across stimulation sites is patient specific. These results suggest two strategies for optimizing patient performance. One strategy is to create a processor map that utilizes only those stimulation sites where performance on basic perceptual tasks is best. In support of this approach, previous studies have shown that patients tolerate a reduction in the number of stimulation sites well and that there is sometimes an improvement in performance when sites where perception is poor are removed from the processor map. A second strategy is to individually optimize the stimulation parameters on a site-by-site basis. It is known for example that stimulus level can be adjusted to improve temporal acuity. Implementation of these two strategies requires a better understanding of the basic principles underlying across-site patterns of perception in cochlear implants. Specifically, the following questions must be addressed. (1) To what extent are across-site patterns of perception similar for all perceptual measures? For example, do the underlying conditions that cause poor temporal perception also affect spatial resolution? (2) What are the relative contributions of the various psychophysical acuities to speech recognition? For example, would it be better to enhance temporal acuity at the expense, if necessary, of spatial acuity? (3) Do spatial and temporal acuity show similar dependency on stimulus level? These issues will be addressed using psychophysical and speech recognition studies in implanted human subjects. The work will deepen our understanding of the mechanisms underlying across-subject variation in speech recognition performance with cochlear implants and serve as a guide for establishing and testing clinical procedures to improve performance in individual patients. PUBLIC HEALTH RELEVANCE: Cochlear implant auditory prostheses have been remarkably successful in restoring communication abilities to deaf people and people with severe hearing loss, but there is still large variability in performance among patients using the same implants and processing strategies. Our preliminary studies show that perception with the implant varies from one stimulation site to the next within a patient's multichannel implant so that each individual has strengths and weaknesses. The research proposed in this application will help elucidate some basic characteristic of the across-site patterns of performance and then define and test clinical fitting strategies that will exploit the strengths and potentially improve prosthetic hearing in thousands of individual patients.