COMPLEX AUDITORY PROCESSING WITH COCHLEAR IMPLANTS

描述(申请人提供)：人工耳蜗(CI)成功地将听觉信息传递给严重听力障碍和深度失聪的人。然而，它们不会在嘈杂的背景下或在竞争对手的演讲者在场的情况下成功。虽然研究表明，大脑可以通过自上而下的处理来学习适应不利的听力条件，但学习和自上而下的机制只有在传输到听觉系统的信息严重退化时才能起到有限的帮助。我们工作的长期目标是揭示CI听者听觉敏感度的基本机制，并将这些发现与他们对该设备的语音感知联系起来。越来越明显的是，为了改善声音质量、说话人识别、信源分离和在噪声中收听，配置项需要提供关于语音频谱的细粒度信息。然而，目前还不清楚CI听者在多通道刺激环境中能够在多大程度上处理这样的信息。拟议的实验将量化多通道光谱模式识别、多通道时间模式识别以及在竞争、波动的掩蔽者存在的情况下CI收听者的多通道频谱-时间交互作用。将探索新的刺激方法，如电流导向虚拟通道刺激，以及更集中的刺激模式的效果。结果将提供一个关于跨通道相互作用在复杂的动态电刺激中的作用的观点。同时，音素识别、性别识别和语音语调识别将在安静和竞争的噪音中进行测量。将这些结果与从心理物理实验中获得的结果进行比较，可以深入了解电刺激的那些方面，这些方面对于现实听力情况下的语音识别至关重要。这些结果不仅对CI听者复杂的听觉加工有重要的基础理解，而且在更广泛的意义上也将适用于听力受损和听力正常的听者对复杂刺激的听觉加工。这项拟议工作的临床意义在于，这些发现将有助于为未来的听觉假体开发临床评估工具和新的语音处理器设计。

DESCRIPTION (provided by applicant): Cochlear implants (CIs) successfully deliver auditory information to the severely hearing impaired and the profoundly deaf. However, they do not succeed in noisy backgrounds, or in the presence of competing speakers. While research has shown that the brain can learn to adapt to adverse listening conditions using top-down processing, learning and top-down mechanisms can only help to a limited extent when the information transmitted to the auditory system is severely degraded. The long-term goal of our work is to uncover basic mechanisms underlying CI listeners' auditory sensitivity, and to relate these findings to their speech perception with the device. It is increasingly apparent that, to improve sound quality, speaker recognition, source segregation, and listening in noise, CIs will need to provide fine-grained information about the speech spectrum. It is unclear, however, to what extent CI listeners can process such information in a multi-channel stimulation context. Proposed experiments will quantify multi-channel spectral pattern recognition, multi-channel temporal pattern recognition, and multi-channel spectro-temporal interactions in CI listeners in the presence of competing, fluctuating maskers. Novel stimulation methods, such as current-steered virtual channel stimulation, will be explored, as will effects of more focused stimulation mode. Results will provide a view of the role of across-channel interactions in complex, dynamic electrical stimuli. In parallel, measures of phoneme recognition, gender recognition, and speech intonation recognition will be made, both in quiet and in competing noise. A comparison of these results to the results obtained from the psychophysical experiments will yield insight into those aspects of electrical stimulation that are critical for speech recognition in realistic listening situations. The results will not only yield important fundamental understanding of complex auditory processing by CI listeners, but they will also apply, in a broader sense, to auditory processing of complex stimuli by hearing-impaired and normal hearing listeners. The clinical relevance of the proposed work is that the findings will contribute to the development of clinical assessment tools and new speech processor designs for future auditory prostheses.