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 (CI) 为大多数聋人提供了出色的功能性听力，但在噪音或音乐等复杂声音中聆听时，其益处有限。为了提高人工耳蜗的性能，我们需要确定这些困难的听力情况下最重要的线索，并找到通过植入物呈现这些线索的方法。提高光谱选择性应该可以改善植入物的性能，但受到物理、生物和感知因素的限制。对于个体植入听者来说，频谱选择性可能会受到不良电极放置和/或不良神经存活的限制。人们已经研究了新技术（电流聚焦）来减少电流扩散，从而提高光谱选择性。然而，我们实验室的数据表明，电流聚焦仅减少了约一半测试患者的兴奋扩散 (SOE)。只有当 SOE 实际减少时，才能预期当前聚焦带来的性能改进。在拟议的实验中，我们将提供第一个受试者内对噪声和音乐任务中语音变化的测量（具体目标 3），因为它们与多通道频谱模式辨别的变化（具体目标 2）和单通道 SOE 的减少（具体目标 1）有关。我们期望发现当前的重点可以导致国有企业的减少，这反过来又会导致 改善噪音中的言语和音乐表现。然而，由于局部神经存活、电极放置和可变的局部阻抗，我们预计只能在一小部分患者中实现 SOE 的降低。因此，我们还将研究快速（且与临床相关）的方法来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电流聚焦来提高某些患者的功能光谱分辨率，并确定在临床相关程序中哪些患者将从电流聚焦中受益。我们假设，如果电流聚焦可以减少激励的传播，那么光谱分辨率将会提高，并提高在具有挑战性的聆听条件（例如，噪声中的语音、音乐）中的 CI 性能。拟议的研究意义重大，因为它的目的是：a）评估 SOE 变化、多通道辨别以及语音和音乐任务表现之间的关系，b）提高 CI 听众的表现。该研究具有创新性，是第一项在受试者内部调查单通道 SOE 对健康的影响的研究。 通过直接操纵电流扩展程度来提高多通道频谱和语音处理器性能。该研究方法结合了客观测量（ECAP）、主观描述、单通道和多通道心理物理学以及实验信号处理的评估，以更好地了解谁可能从当前的聚焦中受益以及在什么情况下受益。 公共健康相关性：人工耳蜗 (CI) 用户在挑战听力条件（例如噪声中的语音和音乐感知）时遇到困难，可能是因为每个电极的通道相互作用。我们将研究“电流聚焦”是否会减少激励的传播，提高多通道频谱分辨率，并在困难的聆听条件下提供更好的性能。此外，我们将研究快速（即临床相关）方法来确定哪些患者将从限制兴奋的传播中受益。