The relationship between precursor level and the temporal effect.
The relationship between precursor level and the temporal effect.
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DOI：
10.1121/1.2821977
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发表时间：
2008-02
期刊：
影响因子：
--
通讯作者：
E. Strickland
中科院分区：
文献类型：
--
作者：
E. Strickland
先前的研究表明，掩蔽的时间效应可能与耳蜗增益的降低一致。用来证明这一点的一个范例是测量长时间掩模的水平，以掩盖在掩模开始时出现的短时间音调。当信号在之前的刺激（要么是掩模的延伸，要么是单独的前体）之后以较低的信噪比检测到信号时，时间效应就会显现出来。本研究考察了这种影响是否取决于前体水平。信号是一个10毫秒，4千赫的音调。掩码是200ms。固定电平前驱体与掩膜具有相同的频率特性，为205 ms。掩模和前体在信号频率上要么没有陷波，要么有宽的陷波。对于给定的前驱体电平，确定掩模电平随信号电平的增长。这些数据被用来估计输入输出函数。结果表明，当掩模和前驱体中没有陷波时，信号频率处的增益呈梯度下降，当有大陷波时，抑制呈梯度下降。这些结果可能与内侧耳蜗反射的作用一致。
Previous studies have suggested that temporal effects in masking may be consistent with a decrease in cochlear gain. One paradigm used to show this is to measure the level of a long-duration masker required to just mask a short-duration tone that occurs near masker onset. The temporal effect is revealed when the signal is detected at a lower signal-to-noise ratio following preceding stimulation (either an extension of the masker or a separate precursor). The present study examined whether this effect depends on precursor level. The signal was a 10-ms, 4-kHz tone. The masker was 200 ms. A fixed-level precursor had the same frequency characteristics as the masker, and was 205 ms. The masker and precursor had either no notch or a wide notch about the signal frequency. For a given precursor level, the growth of masker level with signal level was determined. These data were used to estimate input-output functions. The results are consistent with a graded decrease in gain at the signal frequency when there is no notch in the masker and precursor, and a graded decrease in suppression when there is a large notch. These results could be consistent with the action of the medial olivocochlear reflex.