Reduction in spread of excitation as predictor multi-channel spectral resolution

减少激励扩散作为预测器多通道光谱分辨率

• 批准号: 8373787
• 负责人: David M Landsberger
• 金额: $ 44.63万
• 依托单位: HOUSE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8373787
• 关键词: Action Potentials; Apical; Biological; Clinical; Cochlea; Cochlear Implants; Cognitive; Complex; Cues; Data; Descriptor; Detection; Differential Threshold; Discrimination; Electrodes; Evaluation; Frequencies; Goals; Hearing; Hearing Impaired Persons; Implant; Implanted Electrodes; Individual; Light; Location; Masks; Measurement; Measures; Medial; Methods; Music; Nerve; Noise; Patients; Pattern; Perception; Performance; Physiological; Pitch Perception; Procedures; Process; Psychophysics; Psychophysiology; Research; Resolution; Signal Transduction; Site; Speech; Speech Discrimination; Speech Perception; Stimulus; Techniques; Testing; clinically relevant; computerized data processing; design; electric impedance; improved; innovation; relating to nervous system; research study; sound

DESCRIPTION (provided by applicant): Cochlear implants (CIs) provide excellent functional hearing to most deaf individuals, but the benefits are limited when listening in noise or to complex sounds like music. To improve cochlear implant performance we need to identify the most important cues for these difficult listening situations and find ways to present these cues through the implant. Improving spectral selectivity should improve implant performance but is limited by physical, biological and perceptual factors. For an individual implant listener, spectra selectivity may be limited by poor electrode placement and/or poor nerve survival. New techniques (current focusing) have been investigated to reduce current spread and therefore improve spectral selectivity. However, data from our lab suggest that current focusing only reduces spread of excitation (SOE) in about half of the patients tested. Performance improvements from current focusing can only be expected when the SOE is actually reduced. In the proposed experiments, we will provide the first within-subject's measurements of changes in speech in noise and music tasks (Specific Aim 3) as they relate to changes in multi-channel spectral pattern discrimination (Specific Aim 2) and reduction in single-channel SOE (Specific Aim 1). We expect to find that current focusing can result in reductions in SOE, which in turn will produce improvements in speech in noise and music performance. However, because of local neural survival, electrode placement, and variable local impedances, we expect to find that a reduction in SOE will only be achievable in a subset of patients. Therefore, we will also investigate quick (and clinically relevant) methods of predicting which patients will benefit from current focusing (experiments 2 and 3). The overall goals of this research are to determine if functional spectral resolution can be improved via current focusing for some patients and to determine in a clinically relevant procedure which patients would benefit from current focusing. We hypothesize that if current focusing can reduce the spread of excitation, then spectral resolution will be increased and improve CI performance in challenging listening conditions (e.g., speech in noise, music). The proposed research is significant because it aims to: a) evaluate the relationship between changes in SOE, multi-channel discrimination, and performance in speech and music tasks, b) improve performance for CI listeners. The research is innovative as the first study to investigate within subjects the effect of single-channel SOE on multi-channel spectral and speech processor performance by directly manipulating the degree of current spread. The research approach combines objective measures (ECAPs), subjective descriptors, single- and multi-channel psychophysics, and evaluations of experimental signal processing to better understand who might benefit from current focusing, and under what circumstances. PUBLIC HEALTH RELEVANCE: Cochlear implant (CI) users have difficulty in challenging listening conditions (e.g. speech in noise and music perception) presumably because of channel interactions from each electrode. We will investigate if "current-focusing" will reduce the spread of excitation, increase multi-channel spectral resolution, and provide better performance in difficult listening conditions. Furthermore, we will investigate quick (i.e. clinically-relevant) methods of determining which patients would benefit from restricting the spread of excitation.

描述（由申请人提供）：人工耳蜗（CIS）为大多数聋人提供了出色的功能性听力，但是在噪音或诸如音乐之类的复杂声音时，好处是有限的。为了提高人工耳蜗的性能，我们需要确定这些困难聆听情况的最重要的线索，并找到通过植入物呈现这些线索的方法。提高光谱选择性应提高植入物的性能，但受到物理，生物学和感知因素的限制。对于单个植入物的侦听器，光谱选择性可能受到较差的电极位置和/或神经存活不良的限制。已经研究了新技术（当前聚焦）以减少当前的扩散，从而提高光谱选择性。但是，我们实验室的数据表明，当前聚焦仅在大约一半的测试患者中减少激发（SOE）的扩散。只有在SOE实际降低时，才可以预期改善当前聚焦的性能。在拟议的实验中，我们将提供第一个受试者内部对噪声和音乐任务中语音变化（特定目标3）的测量值（特定的目标3），因为它们与多渠道光谱歧视的变化有关（特定的目标2）和单个单个单一的降低渠道SOE（特定目标1）。我们希望发现当前的聚焦会导致国有企业的减少，而这反过来将 在噪音和音乐表演方面的语音改善。但是，由于局部神经存活，电极的放置和可变的局部阻抗，我们希望发现SOE的减少只能在一部分患者中实现。因此，我们还将研究快速（和临床上相关的）方法，以预测哪些患者将从当前的聚焦中受益（实验2和3）。这项研究的总体目标是确定是否可以通过目前的某些患者进行当前的注意力来改善功能光谱分辨率，并确定患者将从当前的聚焦中受益的临床相关程序。我们假设，如果当前的焦点可以减少激发的传播，那么光谱分辨率将增加并在具有挑战性的聆听条件下提高CI的性能（例如，噪音，音乐中的语音）。拟议的研究之所以重要，是因为它的目的是：a）评估SOE的变化，多渠道歧视和语音和音乐任务的性能之间的关系，b）提高CI听众的性能。这项研究具有创新性，是第一个研究主体中的研究的研究 多通道光谱和语音处理器性能直接操纵当前扩散程度。该研究方法结合了客观措施（ECAP），主观描述符，单渠道心理物理学以及对实验信号处理的评估，以更好地了解谁可能从当前的注意力中以及在什么情况下受益。 公共卫生相关性：耳蜗植入物（CI）用户在挑战聆听条件（例如噪音和音乐感知中的语音）方面很难，大概是因为每个电极的频道相互作用。我们将调查“以电流为准”是否会减少激发的传播，增加多通道光谱分辨率，并在困难的听力条件下提供更好的性能。此外，我们将迅速研究（即临床上与临床相关的）方法，以确定哪些患者将受益于限制激发的传播。