COMPLEX AUDITORY PROCESSING WITH COCHLEAR IMPLANTS

描述（由申请人提供）：人工耳蜗（CIs）成功地为重度听力障碍和重度失聪的人提供听觉信息。然而，在嘈杂的背景下，或者在有相互竞争的发言者在场的情况下，它们就不能成功了。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，但当传递给听觉系统的信息严重退化时，学习和自上而下的机制只能在有限的程度上起作用。我们工作的长期目标是揭示CI听众听觉敏感性的基本机制，并将这些发现与他们使用该设备的语音感知联系起来。越来越明显的是，为了提高音质、说话人识别、源隔离和噪声听力，ci将需要提供关于语音频谱的细粒度信息。然而，目前尚不清楚，在多通道刺激环境下，CI听者能在多大程度上处理这些信息。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，波动掩模存在下CI侦听器中的多通道光谱-时间相互作用。将探索新的刺激方法，如电流导向的虚拟通道刺激，以及更集中的刺激模式的效果。结果将提供跨通道相互作用在复杂，动态电刺激中的作用。同时，在安静环境和竞争噪声环境下进行音素识别、性别识别和语音语调识别。将这些结果与心理物理实验结果进行比较，将有助于深入了解电刺激在现实听力环境中对语音识别至关重要的那些方面。研究结果不仅将对CI听者的复杂听觉处理产生重要的基础理解，而且还将在更广泛的意义上应用于听力受损和正常听者对复杂刺激的听觉处理。这项工作的临床意义在于，研究结果将有助于临床评估工具的开发和未来听觉假体的新语音处理器设计。

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.