Spectro-temporal interactions in electric and acoustic processing and auditory pe

描述（由申请人提供）：尽管在过去的三十年中人工耳蜗（CI）技术和性能取得了巨大的进步，但通过人工耳蜗（CI）的语音感知仍然比正常听力（NH）差得多，特别是在嘈杂的背景下。听力受损（HI）的听众即使在配戴助听器后也会遇到类似的困难。本研究的长期目标是通过更深入地了解在具有挑战性的声学环境中促进和限制语音感知的基本机制，通过ci和助听器改善听觉和言语感知。第一个目的是研究听觉增强和环境效应-类似于视觉中的负后像和颜色恒定效应。这些效果可能有助于使传入的声音“正常化”，并在面对不同房间、不同说话者和不同声学背景产生的广泛不同的声学时产生感知不变性。对于HI或CI侦听器中的这些影响知之甚少。如果增强和环境效应可以在CI使用者中测量，结果将为基于耳蜗增益输出控制的最新理论提供证据。如果HI和/或CI监听器没有表现出增强效果，那么我们的结果将指导新的信号处理方案，通过信号处理“重建”感知规范化的重要方面。第二个目标测试了频谱分辨率有助于分离具有不同频谱内容的声音的假设，并且在频谱匹配噪声中通常的语音感知测量低估了频谱分辨率在许多真实情况下的重要性，在这些情况下，掩蔽声音通常与目标声音不匹配。然后，我们将基于Aim 1的研究结果研究光谱分辨率和随时间变化的光谱增益变化之间的相互作用。该结果将导致新的临床言语感知测量的发展，提供有关频谱分辨率静态和动态方面的信息，并预测日常听力条件下的表现。这些措施将用于指导和验证在目标1下开发的新信号处理方案。在第二部分中，我们将检验“稳定”噪声中固有的时间包络波动在限制CI听者的语音感知方面发挥重要作用的假设。我们将测量噪声中的语音感知，并将其与不产生幅度波动的宽带掩模中的语音感知进行比较。在没有虚假固有噪声波动的情况下，对不同时间调幅频带对语音感知的影响进行参数化研究，将为CI用户提供不同幅度频率对语音掩蔽的相对贡献的估计。总的来说，所提出的工作将进一步加深我们对正常听力、受损听力和电听力中频谱和时间处理动态方面的基本知识，并将导致信号处理的新方法，有望改善听力受损和CI听众在复杂和不同声学背景下的语音感知。

DESCRIPTION (provided by applicant): Despite tremendous progress in cochlear implant (CI) technology and performance over the past three decades, speech perception through a CI remains considerably poorer than in normal hearing (NH), particularly in noisy backgrounds. Similar difficulties are experienced by hearing-impaired (HI) listeners, even after hearing-aid fitting. The long-term goal of this research is to improve auditory and speech perception via CIs and hearing aids, through a greater understanding of the basic mechanisms that contribute to, and limit, the perception of speech in challenging acoustic environments. The first aim studies auditory enhancement and context effects - similar to the negative afterimage and color constancy effects in vision. These effects may help "normalize" the incoming sound and produce perceptual invariance in the face of the widely varying acoustics produced by different rooms, different talkers, and different acoustic backgrounds. Little is known about these effects in either HI or CI listeners. If enhancement and context effects can be measured in CI users, the results will provide evidence against recent theories based on efferent control of cochlear gain. If HI and/or CI listeners do not exhibit enhancement effects, then our results will guide novel signal processing schemes that will "recreate" important aspects of perceptual normalization through signal processing. The second aim tests the hypothesis that spectral resolution helps segregate sounds with different spectral content, and that the usual measures of speech perception in spectrally matched noise underestimate the importance of spectral resolution in many real-world situations, where masking sounds are not usually matched to target sounds. We will then investigate the interaction between spectral resolution and time-dependent spectral gain changes based on the findings from Aim 1. The results should lead to the development of new clinical measures of speech perception that provide information regarding static and dynamic aspects of spectral resolution, and predict performance in everyday listening conditions. These measures will be used to guide and validate the new signal processing schemes developed under Aim 1. In the second part, we will test the hypothesis that the temporal envelope fluctuations inherent in "steady" noise play an important role in limiting speech perception of CI listeners. We will measure speech perception in noise and compare it to speech perception in broadband maskers that produce no amplitude fluctuations. A parametric study of the effect of different temporal amplitude modulation frequency bands on speech perception, in the absence of spurious inherent noise fluctuations will provide estimates in CI users of the relative contributions of different amplitude frequencies to speech masking. Overall, the proposed work will further our fundamental knowledge about dynamic aspects of spectral and temporal processing in normal, impaired, and electric hearing, and will lead to new approaches in signal processing that hold the promise of improving speech perception for hearing- impaired and CI listeners in complex and varying acoustic backgrounds.