NEURAL ENCODING OF COMPLEX SOUNDS

描述（由申请人提供）：正常听觉系统具有用于从环境中提取行为相关的声学信号的非常适合的过程，特别是在具有挑战性的听音条件下，例如在存在竞争信号或背景噪声的情况下。然而，这些过程在生理学上知之甚少。这个建议的目的是了解一个特定的听觉处理非线性（听觉频谱对比度调谐）的神经生物学，因为它涉及到嘈杂的发声表示在哺乳动物的听觉系统。目标1将涉及测量听觉神经元用于估计频谱对比度的声音频率范围。这一信息将被证明是至关重要的了解对比度调谐是如何计算的生物。目标2将确定神经元调谐到频谱对比度的输入/输出函数的编码部分。这个功能的性质将允许我们推断出这个特定的处理特征是如何在稍后的处理阶段被神经元读出的。目标3将直接测试对比度调谐神经元对嵌入背景噪声中的发声的响应，期望噪声发声将在这些神经元中产生尖峰响应，这些神经元随着噪声量的增加而携带更多信息，达到一定限度。完成后，这项研究将导致在一个潜在的重要的响应特性在中央听觉系统与工程降噪系统，这可能有很大的潜力依赖于一个听力假体的日常生活行为的个人的潜在相关性的理解。这个项目解决了我们的长期目标，更清楚地了解环境和通信声音是如何编码在哺乳动物的听觉系统在嘈杂的条件下。我们将通过探索灵长类听觉皮层神经元的特定非线性处理特征是如何产生的，编码刺激特征和对噪声退化的发声做出反应来实现这一目标。最终，这些信息可能有助于改进算法，使助听器和人工耳蜗等听觉假体设备在日常嘈杂的环境中更好地发挥作用。

DESCRIPTION (provided by applicant): The normal auditory system possesses exquisitely well-adapted processes for extracting behaviorally relevant acoustic signals from the environment, especially under challenging listening conditions such as in the presence of competing signals or background noise. These processes are poorly understood physiologically, however. The objective of this proposal is to understand the neurobiology of a particular auditory processing nonlinearity (auditory spectral contrast tuning) as it relates to noisy vocalization representation in the mammalian auditory system. Aim 1 will involve measuring the sound frequency range that auditory neurons use for making estimates of spectral contrast. This information will prove critical for understanding how contrast tuning is computed biologically. Aim 2 will determine the coding portion of the input/output function for neurons tuned to spectral contrast. The nature of this function will allow inferences to be made about how this particular processing feature is read out by neurons at a later processing stage. Aim 3 will directly test the responses of contrast-tuned neurons to vocalizations embedded in background noise, with the expectation that noisy vocalizations will produce spiking responses in these neurons that carry more information as the amount of noise increases, up to a limit. When completed, this research will result in an improved understanding of a potentially important response property in the central auditory system with potential relevance for engineered noise-reduction systems, which could have great potential for individuals reliant upon a hearing prosthesis for acts of daily living. This project addresses our long-term goal of understanding more clearly how environmental and communication sounds are encoded in the mammalian auditory system under noisy conditions. We will achieve this goal by exploring how particular nonlinear processing features of neurons in primate auditory cortex are created, encode stimulus features and respond to vocalizations degraded by noise. Ultimately, this information may aid in refining algorithms that could allow auditory prosthesis devices such as hearing aids and cochlear implants to function better in everyday noisy environments.