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

描述（由申请人提供）：尽管在过去三十年中人工耳蜗（CI）技术和性能取得了巨大进步，但通过CI的言语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）的听众即使在助听器装配之后也经历类似的困难。这项研究的长期目标是通过CI和助听器改善听觉和言语感知，通过更好地理解在具有挑战性的声学环境中有助于和限制言语感知的基本机制。第一个目标是研究听觉增强和背景效应-类似于视觉中的负后像和颜色恒常性效应。这些效果可以帮助“归一化”传入的声音，并且在面对由不同房间、不同谈话者和不同声学背景产生的广泛变化的声学效果时产生感知不变性。很少有人知道这些影响在HI或CI听众。如果增强和上下文的影响，可以测量CI用户，结果将提供证据，对最近的理论的基础上传出控制耳蜗增益。如果HI和/或CI听众没有表现出增强效果，那么我们的研究结果将指导新的信号处理方案，将“重新创建”感知归一化的重要方面，通过信号处理。第二个目标测试的假设，频谱分辨率有助于隔离声音与不同的频谱内容，通常的措施，语音感知频谱匹配的噪声低估了频谱分辨率的重要性，在许多现实世界的情况下，掩蔽的声音通常不匹配的目标声音。然后，我们将研究光谱分辨率和时间依赖的光谱增益变化的基础上，从目标1的结果之间的相互作用。结果应导致新的临床措施的语音感知的发展，提供有关静态和动态方面的频谱分辨率的信息，并预测在日常听力条件下的性能。这些措施将用于指导和验证根据目标1开发的新信号处理方案。在第二部分中，我们将测试的假设，即时间包络波动固有的“稳定”的噪声发挥了重要作用，限制语音感知的CI听众。我们将测量噪声中的言语感知，并将其与不产生振幅波动的宽带掩蔽器中的言语感知进行比较。在没有杂散固有噪声波动的情况下，不同时间幅度调制频带对语音感知的影响的参数研究将提供CI用户中不同幅度频率对语音掩蔽的相对贡献的估计。总的来说，拟议的工作将进一步我们的基本知识的频谱和时间处理的动态方面在正常的，受损的，和电听力，并将导致新的方法在信号处理，持有改善语音感知听力受损和CI听众在复杂和变化的声学背景的承诺。

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.