DYNAMIC CHARACTERISTICS OF AUDITORY MASKING

拟议的实验旨在提供 听觉动态特性信息 处理. 有两个独立但相关的研究方向。 第一个原因是，最近的证据表明， 同时的纯色调掩蔽是时变的，结果， 对频率选择性的心理物理测量 在第一个100到150毫秒的刺激期间。 的目标 研究的第一步是进一步了解 负责时间效应的机制，以确定 感音神经性听力损失是否影响这些机制， 以确定这些时间效应在多大程度上起作用， 对复杂信号如语音的听觉处理。 具体项目包括进一步研究 听力正常受试者和听力正常受试者的纯音掩蔽 感音神经性听力损失，以及 复合掩蔽（包括元音和辅音-元音） 听力正常受试者的掩蔽者。 在这些假设中， 测试的是，负责提高频率的机制， 随着时间的推移，听力正常的受试者的选择性受损， 感音神经性听力损失患者。 第二条研究路线的动机是，听力- 受损个体通常难以理解 在嘈杂的环境中说话。 这项研究的目的是 评估假设，至少有一些困难是由于 无法检测到缓慢的（振幅）调制， 在存在背景噪声的情况下的语音，诸如来自 竞争的来源。 这条研究路线涉及研究 通过幅度调制信号的掩蔽， 听力正常和听力受损的调制掩蔽声 科目 希望拟议研究的结果将进一步 我们对动态听觉的机制的理解 处理;进一步了解外围设备 频率选择性恶化的机制 在感音神经性听力损失的受试者中， 理解复杂信号的处理，如语音。

The proposed experiments have been designed to provide information on the dynamic characteristics of auditory processing. There are two separate but related lines of research. The first is motivated, in part, by recent evidence that simultaneous pure-tone masking is time-varying and, as a result, that psychophysical measures of frequency selectivity sharpen during the first 100 to 150 ms of stimulation. The goals of the first line of research are to further our understanding of the mechanisms responsible for the temporal effect, to determine whether sensorineural hearing loss affects those mechanisms, and to determine to what extent those temporal effects play a role in the auditory processing of complex signals such as speech. Specific projects include further studies of temporal effects in pure-tone masking in normal-hearing subjects and in subjects with sensorineural hearing loss, and studies of temporal effects in masking by complex (including vowel and consonant-vowel) maskers in normal-hearing subjects. Among the hypotheses to be tested is that the mechanisms responsible for enhancing frequency selectivity over time in normal-hearing subjects are damaged in subjects with sensorineural hearing loss. The second line of research is motivated by the fact that hearing- impaired individuals typically have difficulty understanding speech in noisy environments. The goal of this research is to evaluate the hypothesis that at least some of that difficulty is due to an inability to detect the slow (amplitude) modulations in speech in the presence of a background noise, such as speech from a competing source. This line of research involves studying the masking of an amplitude-modulated signal by an amplitude- modulated masker in normal-hearing and hearing-impaired subjects. It is hoped that the results from the proposed studies will further our understanding of the mechanisms involved in dynamic auditory processing; further our understanding of the peripheral mechanisms involved in the deterioration of frequency selectivity in subjects with sensorineural hearing loss; and further our understanding of processing of complex signals such as speech.