NORMAL & IMPAIRED TEMPORAL PROCESSING OF COMPLEX SOUNDS

我们的长期目标是建立听觉的量化模型 听力正常和听力受损时的知觉。这样的模式提高了我们的 对正常和受损的听觉过程的理解。他们还帮助 显著地为听力障碍提供了更好的诊断工具 以及更好地康复听力受损的听众。建议数 该项目旨在研究听觉系统如何处理时间-- 改变激励模式并形成多频带判决规则以 感知的响度、粗糙度和调制模式(包络) 复杂的声音。因为这些过程的输入被认为是 从激发模式出发，拟议的工作提供了进一步的 激励模式与多带判决概念的检验 规则提供了一个通用的框架，用于对正常和 听力受损。模型预测将与心理声学进行比较 耳蜗病患者的强迫选择实验数据 收听者和正常收听者在安静和地下接受测试 等效阈值掩蔽，ETM。ETM是通过呈现一个 连续掩码，其频谱形状可产生相等的阈值 对于一个受损的听众来说。这些实验还将提供一种 关于Brief的听觉处理的大量急需数据集 幅度波动，这是一个重要的先决条件 对言语的感知。这些实验的具体目的是：i) 检验以下假设：刺激分量的响度贡献 AT阈值随着阈值的增加而增加，即使对于 隔离低于其阈值的组件，响度匹配 将在静音中获得纯色调和多色调复合体 在两个水平的掩蔽下。2)检验时间的假设 响度的积分依赖于电平，并且具有简单的关系 内部强度代码，响度匹配不同的音调 持续时间将作为级别和频率的函数获得。3)至 测试以下假设：感知到的粗糙度大小 与响度、粗糙度匹配的时间积分成反比 在部分屏蔽的调幅音调之间将获得如下 载波音调的电平和频率的函数。4)测试 假设跨通道处理促进了对 相对较快的、部分相关的包络波动 包络频率的心理测量函数的频率域 识别和粗糙度匹配将与噪声带匹配 通过对正弦调幅宽带噪声进行滤波而产生。 所有这些实验都是由特定的听觉模型驱动的。 系统和歧视过程，但不考虑我们的模型 成功后，在拟建项目中获得的数据将大大增加 对于我们对听力正常和受损的理解，将是非常重要的 用于开发和测试加工过程的一般模型 由听觉系统发出的动态信号。

Our long-term objective is to formulate quantitative models of auditory perception in both normal and impaired hearing. Such models improve our understanding of normal and impaired auditory processes. They also aid significantly in providing better diagnostic tools for hearing Impairment and better rehabilitation of hearing-impaired listeners. The proposed project aims to investigate how the auditory system processes time- varying excitation patterns and forms multiband decision rules to perceive loudness, roughness, and modulation patterns (envelopes) of complex sounds. Because the Input to these processes is conceived as originating from excitation patterns, the proposed work provides further testing of the concept that excitation patterns and multi-band decision rules provide a general framework for quantitative modeling of normal and impaired hearing. Model predictions will be compared to psychoacoustic data obtained in forced-choice experiments with cochlearly impaired listeners and with normal listeners tested in the quiet and under Equivalent-Threshold Masking, ETM. ETM is produced by presenting a continuous masker that is spectrally shaped to produce thresholds equal to those of an impaired listener. These experiments also will provide an extensive set of sorely needed data on auditory processing of brief amplitude fluctuations, which is an important prerequisite for the perception of speech. The specific aims of the experiments are: i) To test the hypothesis that the loudness contribution of stimulus components at threshold increases with threshold and is greater than zero even for components that are below their thresholds in isolation, loudness matches will be obtained between pure tones and multitone complexes in the quiet and under two levels of masking. 2) To test the hypothesis that temporal integration for loudness depends on level and has a simple relation to the internal intensity code, loudness matches between tones of different durations will be obtained as a function of level and frequency. 3) To test the hypothesis that the perceived magnitude of roughness is inversely related to temporal integration for loudness, roughness matches between partially masked amplitude-modulated tones will be obtained as a function of level and frequency of the carrier tones. 4) To test the hypothesis that across-channel processing facilitates the perception of relatively fast, partially correlated envelope fluctuations in different frequency regions, psychometric functions for envelope-frequency discrimination and roughness matches will be obtained with noise bands produced by filtering a sinusoidally amplitude modulated broadband noise. All these experiments are motivated by specific models of the auditory system and discrimination processes in it, but regardless of our models' success, the data obtained in the proposed project will add significantly to our understanding of normal and impaired hearing and will be important for the development and testing of general models for the processing of dynamic signals by the auditory system.