INTENSITY PROCESSING IN EARS WITH SHIFTED THRESHOLDS

本研究的总体目标是更好地了解 在正常和受损的人中，强度处理的机制 耳朵 本提案的主要部分审查了以下方面之间的关系： 响度增长和识别电平的小增量的能力， 这被称为强度分辨率。 特别感兴趣的是 已知或可能改变强度分辨率的条件， 响度，例如将音调添加到复杂音调或检测 在宽带噪声开始期间的短音调（即，过冲）。 这项研究的另一个阶段是考察强度与 分辨力和响度，以测试 假设适应是负责异常强度 在这些监听器中进行处理。 患有听神经瘤的受试者将能够 对激发模式模型的关键测试， 正常和受损听力的强度处理。 第三系列 实验研究了认知因素（如记忆和 上下文）对响度和强度分辨率的影响。 不同的实验 刺激上下文（例如，前掩蔽与线索）将提供更多的数据 与日常听力条件相关的信息， 上下文，但固定和可变的上下文都需要研究， 将认知机制与感官机制分开。 这项拟议的研究 将提供当前模型的关键测试， 强度分辨率，并应提供有关机制的见解 这些现象背后。 这些实验的数据也应该 证明在设计和安装hering假体中是有用的，例如在 耳蜗植入体通道独立性的评价。

The overall goal of this research is to develop a better understanding of the mechanisms that underlie intensity processing in normal and impaired ears. A major portion of this proposal examines the relation between loudness growth and the ability to identify small increments in level, which is known as intensity resolution. Of particular interest are conditions that are known or ar likely to modify intensity resolution and loudness, such as adding tones to a complex tone or the detection of a brief tone during the onset oa a broadband noise (i.e., overshoot). Another phase of this research examines the relation between intensity resolution and loudness in individuals with acoustic tumors to test the hypothesis that adaptation is responsible for the abnormal intensity processing in these listeners. Subjects with acoustic tumors will enable a critical test of excitation-pattern models invoked typically for modeling intensity processing in normal and impaired hearing. A third series of experiments examines the role of cognitive factors (such as memory and context) on loudness and intensity resolution. Experiments with varied stimulus contexts (e.g., forward masking with cues) will provide data more relevant to everyday listening conditions than those from fixed stimulus contexts, but both fixed and variable contexts need to be studied to separate cognitive mechanisms from sensory ones. This proposed research will provide critical tests of current models for relating loudness and intensity resolution and should provide insights into the mechanisms underlying these phenomena. The data from these experiments also should prove useful in the design and fitting of hering prostheses, such as in the evaluation of channel independence in cochlear implants.