ENVELOPE & CO-MODULATION CUES IN NORMAL & IMPAIRED EARS

我们的长期目标是了解 听觉系统，将允许定量建模 正常和受损的人的音调、噪音和语言的发音 听证。这样的模型不仅将提高我们对 正常的听觉过程，但也将大大有助于 为听力障碍提供更好的诊断工具 更好地康复听力受损的听众。建议数 该项目的目标是获得一组连贯的参数数据 连续和同时的包络比较。连续的 包络比较是在区分实验中进行的 包络(调幅)频率的差异。 同步包络比较在以下实验中进行测试 共调制线索对包络频率的影响 辨别(即，共调制提示包络频率 区分、CCEFD)和掩蔽(即，共调制 掩蔽释放，CMR)。基于以下内容的强制选择实验 正常监听者、受损监听者和具有 通过遮盖正常耳朵来模拟损伤，我们的目标是 为正常和非正常的心理声学模型奠定坚实的心理基础 听者对包络波动的处理能力受损 不同听觉通道中的包络相关性。我们的特定 目标是(1)确定光谱线索和时间线索在任务中的作用 解释在中获得的定性不同的结果 滤波脉冲串和In的速率辨别实验 双音包络鉴频实验 复合体。将比较包络频率鉴别率 对于双音复合、带通滤波脉冲串和低 将经过滤波的脉冲串乘以正弦。低传球 经过滤波、倍增的脉冲序列具有类似于频带的包络- 经过滤波的脉冲串，但--就像双音复合体--产生 对于给定的包络变化，只有很小的光谱变化 频率(2)检验听众可能能够做到的假设 比较不同频率下的同时调制波形 频率，并利用这些信息来改善对 中一个频率处的包络-频率差 在另一个频率上存在共调制的信号。几个 相关线索、不相关线索、非相关线索的CCEFD实验 也不会有任何提示。(3)映射满足以下条件的参数 管理CCEFD中相关提示的效率。实验 旨在系统地探索频率的影响 信号和提示、提示位置和提示级别之间的分离。(4) 为了检验假设，共调制优势在 CCEFD和CMR来自同一听觉过程--直接 不同频率下的包络比较。的影响 将比较信号频率和包络频率 系统地对CCEFD进行了实验，并对其进行了实验 CMR。这些实验将有助于确定 以及受损听众可能存在缺陷的根本原因 并为信封处理提供重要数据 正常和受损的CCEFD和CMR的定量模拟 听证。

Our long-term objective is to reach an understanding of the auditory system that will allow quantitative modeling of the preception of tone, noise, and speech in both normal and impaired hearing. Such models not only will improve our understanding of normal auditory processes, but also will aid significantly in providing better diagnostic tools for hearing impairment and better rehabilitation of hearing-impaired listeners. The proposed project aims to obtain a coherent set of parametric data on successive and simultaneous envelope comparisons. Successive envelope comparisons are tested in experiments on discrimination of a difference in envelope (amplitude-modulation) frequency. Simultaneous envelope comparisons are tested in experiments on the effect of a co-modulated cue on envelope-frequency discrimination (i.e., Co-modulation Cued Envelope-Frequency Discrimination, CCEFD) and on masking (i.e., Co-modulation Masking Release, CMR). Based on forced-choice experiments in normal listeners, impaired listeners, and listeners with impairments simulated by masking a normal ear, we aim to establish a firm psychoacoustic basis for a model of normal and impaired listeners' processing of envelope fluctuations and envelope correlations in different auditory channels. Our specific aims are (1) To determine the roles spectral and temporal cues in explaining the qualitatively different results obtained in experiments on rate discrimination of filtered pulse trains and in experiments on envelope-frequency discrimination of two-tone complexes. Envelope-frequency discrimination will be compared for two-tone complexes, band-pass filtered pulse trains, and low- pass filtered pulse trains multiplied by a sinusoid. The low-pass filtered, multiplied pulse trains have envelopes similar to band- pass filtered pulse trains, but--like two-tone complexes--produce only small spectral changes for a given change in envelope frequency. (2) To test the hypotheses that listeners may be able to compare simultaneous modulation waveforms at different frequencies and use the information to improve discrimination of an envelope-frequency difference at one frequency in the presence of a co-modulated cue at another frequency. Several experiments on CCEFD with correlated cues, uncorrelated cues, and no cue will be performed. (3) To map the parameters that govern the efficiency of a correlated cue in CCEFD. Experiments are designed to explore systematically the effects of frequency separation between signal and cue, cue position, and cue level. (4) To test the hypothesis that the co-modulation advantage in CCEFD and CMR result from the same auditory process--direct comparison of envelopes at different frequencies. The effects of signal frequency and envelope frequency will be compared systematically in experiments on CCEFD and experiments on CMR. These experiments will aid in determining both the extent and the underlying causes for impaired listeners' probable deficits in envelope processing and provide important data for quantitative modeling of CCEFD and CMR in normal and impaired hearing.