Auditory Neural Coding of Speech

项目摘要 大多数语音对话都是在竞争声音的存在下发生的， 声反射（混响）。听力受损的人经常抱怨 即使在如此复杂的声学环境中理解语音也很困难 很安静。我们提出神经生理学和计算研究， 关于日常环境中倾听的基本问题。我们将记录从 清醒家兔下丘（IC）对复杂声音反应的单个单位 它包含了复杂声学环境的一些特征。具体目标1将 研究神经反应的自然，动态刺激在模拟混响 适合典型教室的环境。我们将研究是否低- 语音中的频率幅度调制可以提供可靠信息的一瞥 这使得神经系统能够准确地编码信号源的位置。我们还将测试IC是否 神经元可以适应不断变化的环境，以优化源代码 混响中的位置和幅度调制。具体目标2将研究神经 用于在存在目标声源的情况下定位和识别目标声源的机构 一个复仇者。我们将测试是否时间线索所提供的振幅或 源波形的调制或目标源的运动可以改善 存在干扰源时目标位置的神经编码。 这项研究代表了一项系统的努力， 超越了对消声空间中简单声源的研究， 逼真的声学环境。它解决了听觉理论中的基本问题， 作为声源分离的神经机制， 混响和时间编码在空间听觉中的作用。它可能会带来更好的， 机械地理解为什么听障和老年听众有更大的 比正常听力的听众理解演讲的困难， 混响和竞争的声音，并指导新的处理发展 助听器和听觉（耳蜗和脑干）植入物的策略， 更好地适应日常环境。

Project Summary Most speech conversations occur in the presence of competing sounds and acoustic reflections (reverberation). Hearing-impaired people often complain of difficulties understanding speech in such complex acoustic environments even if they do well in quiet. We propose neurophysiological and computational studies that address fundamental questions about listening in everyday environments. We will record from single units in the inferior colliculus (IC) of awake rabbits in response to complex sounds that incorporate some features of complex acoustic environments. Specific Aim 1 will study neural responses to naturalistic, dynamic stimuli in simulated reverberant environments appropriate for typical classrooms. We will examine whether low- frequency amplitude modulations in speech can provide glimpses of reliable information that allow accurate neural coding of the source location. We will also test whether IC neurons can adapt to a changing environment in order to optimize the coding of source location and amplitude modulation in reverberation. Specific Aim 2 will study neural mechanisms for localization and identification of a target sound source in the presence of an interferer. We will test whether temporal cues provided by either amplitude modulation of the source waveform or motion of the target source can improve the neural coding of target location in the presence of the interferer. This research represents a systematic effort to move auditory neurophysiology beyond the study of simple sources in anechoic space and towards natural stimuli in realistic acoustic environments. It addresses fundamental issues in auditory theory such as the neural mechanisms for sound source segregation, compensation for the effects of reverberation and the role of temporal coding in spatial hearing. It may lead to a better, mechanistic understanding of why hearing-impaired and elderly listeners have greater difficulties than normal-hearing listeners understanding speech in the presence of reverberation and competing sounds, and guide the development of new processing strategies for hearing aids and auditory (cochlear and brainstem) implants that perform better in everyday environments.