Developing and Testing Models of the Auditory System with and without Hearing Loss

这项提案提出了开发和测试一种新的声学提示处理模型的计划 无论是心理物理任务还是真实世界的听力。掩码范例通常在以下上下文中解释 两种模型：功率谱模型基于一个或多个带通滤波器的响应中的能量 这代表了外围调谐。包络功率谱模型是基于一组 调制滤波器。然而，这些流行的模型无法解释在许多方面的强劲表现 心理物理任务，特别是漫游-或均衡-水平，以及漫游-或均衡-包络-能量任务。 继续使用这些模式在很大程度上是因为缺乏可行的替代方案。在这里，我们提出一种新的， 掩码检测和频谱编码的替代模型，为 有或没有听力损失的听众的心理物理结果的数量。 基于我们最近对掩蔽检测中与包络相关的线索的研究，我们的建议将重点放在 关于神经波动线索在听神经纤维反应中的作用，以及最终这些 线索由中脑中的调制调谐神经元代表。这些提示在健康的耳朵中是强有力的 但是，因为它们强烈地依赖于外围非线性，所以它们在 最常见的听力损失类型。我们将对包络与能量的使用进行详细的测量 个体听者的暗示作为频率和听力阈值的函数。这些结果将提供 个性化模型，将用于预测特定掩蔽和辨别任务的阈值。 我们将使用计算、生理和心理物理工具来测试一个戴面具的眼科模型 检测，重点放在两个经典范例：陷波噪声和前向掩蔽任务。这些 心理物理工具已被广泛用于表征调谐带宽、压缩和时间 在有听力损失和没有听力损失的听众中进行处理。我们将用神经波动重新检查这些任务-- 基于表达的。我们的初步结果表明，外围设备波动的对比度 经络建立了在中脑水平上的刺激特征的表征，该水平在噪声中很健壮 在广泛的层级，从而解决了巡回参数范例的主要挑战。这些 提示是特别强烈的近光谱斜率，因此值得考虑其他刺激特征 具有尖锐的频谱斜率，如摩擦辅音和耳廓提示。因此，我们还建议延长 我们基于耳间神经波动对耳廓频谱斜率的差异的二分法模型 提示，它编码声音的位置和外部化。我们的初步工作表明，神经波动 与二进制和二进制刺激相关联的提示出现在调制频率范围内，其中大多数 的中脑神经元被调谐。在神经波动的框架下考虑这些任务和刺激 CUES为正常和受损耳朵编码刺激光谱提供了一种新的和一般的理解。

This proposal presents plans to develop and test a new model for the processing of acoustic cues in both psychophysical tasks and real-world hearing. Masking paradigms are typically interpreted in the context of two models: The power-spectrum model is based on energy in the responses of one or more band-pass filters that represent peripheral tuning. The envelope-power-spectrum model is based on the responses of a bank of modulation filters. These popular models, however, fail to explain robust performance in a number of psychophysical tasks, especially roving- or equalized-level, and roving- or equalized-envelope-energy tasks. The continued use of these models is largely due to a lack of viable alternatives. Here, we propose a new, alternative model for masked detection and spectral coding that provides a mechanistic explanation for a number of psychophysical results, for listeners with or without hearing loss. Building upon our recent studies of envelope-related cues in masked detection, our proposal focuses on the role of neural-fluctuation cues in the responses of auditory-nerve fibers, and ultimately on how these cues are represented by modulation-tuned neurons in the midbrain. These cues are robust in the healthy ear but, because they are strongly dependent upon peripheral nonlinearities, they are substantially degraded in most common types of hearing loss. We will make detailed measurements on the use of envelope vs. energy cues by individual listeners as a function of frequency and hearing thresholds. These results will provide individualized models that will be used to predict thresholds in specific masking and discrimination tasks. We will use computational, physiological and psychophysical tools to test a diotic model of masked detection, focusing on two classic paradigms: notched-noise and forward-masking tasks. These psychophysical tools have been used extensively to characterize tuning bandwidth, compression, and temporal processing in listeners with and without hearing loss. We will re-examine these tasks with neural fluctuation- based representations. Our preliminary results show that the contrast in fluctuations across peripheral channels establishes a representation of stimulus features at the level of the midbrain that is robust in noise across a wide range of levels, thus addressing the primary challenges of roving-parameter paradigms. These cues are particularly strong near spectral slopes, and thus warrant consideration for other stimulus features with sharp spectral slopes, such as fricative consonants and pinna cues. We therefore also propose to extend our dichotic model based on interaural differences in neural fluctuations to the spectral slopes of pinna cues, which code sound location and externalization. Our preliminary work indicates that neural-fluctuation cues associated with the diotic and dichotic stimuli occur in the modulation frequency range where the majority of midbrain neurons are tuned. Consideration of these tasks and stimuli in the framework of neural-fluctuation cues provides a novel and general understanding for coding stimulus spectra by the normal and impaired ear.