Loudness enhancement and intensity discrimination under forward and backward masking.
Loudness enhancement and intensity discrimination under forward and backward masking.
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前向和后向掩蔽下的响度增强和强度辨别。
DOI：
10.1121/1.416288
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
C. Plack
中科院分区：
文献类型：
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作者：
C. Plack
对于在强烈掩蔽之前100 ms或之后100 ms呈现的30 ms正弦基座，在中等水平下强度辨别性能存在大的劣化[Plack和Viemeister，J. Acoust.美国社会92，3097-3101（1992）]。还已经证明，在掩蔽音调突发之后100 ms呈现的30 ms正弦音调突发的响度在中间水平处增强[Zeng，J. Acoust.美国社会96，2127-2131（1994）]。本实验测量了前向掩蔽和后向掩蔽下的强度辨别和响度增强。一个双阶梯自适应程序被用来匹配一个30 ms，1 kHz的标准正弦曲线的响度在安静的30 ms，1 kHz的正弦曲线的响度后100 ms（前向掩蔽）或100 ms前（后向掩蔽）的110 ms，90 dB，1 kHz的掩蔽正弦曲线。使用两个阶梯的阈值的平均值来确定增强量，并且使用两个阶梯的阈值之间的差来确定强度最小可察觉差（jnd）。四个听众在30和90分贝之间的标准水平范围内进行了测试。对于所有的听众，在前向和后向掩蔽中，jnd和响度在中等水平（40-70 dB）时最大。对于一个给定的听众，有没有实质性的差异下的结果的形式下向前和向后掩蔽相比，虽然有相当大的差异，在个别听众之间的影响的大小。综合所有的数据，对于前掩蔽和后掩蔽，jnd的大小和响度增强的幅度之间存在正相关，尽管这种相关性仅在后掩蔽中显著（p < 0.005）。与Zeng的结果相比，这些数据表明响度增强和jnd增加之间的联系，以及前向掩蔽和后向掩蔽对强度辨别影响的机制之间的联系。这表明，所有这些影响可能是由长期的响度在听觉系统中的整合。
There is a large deterioration in intensity discrimination performance at medium levels for a 30-ms sinusoidal pedestal presented 100 ms before or 100 ms after an intense masker [Plack and Viemeister, J. Acoust. Soc. Am. 92, 3097-3101 (1992)]. It has also been demonstrated that the loudness of a 30-ms sinusoidal tone burst, presented 100 ms after a masking tone burst, is enhanced at mid-levels [Zeng, J. Acoust. Soc. Am. 96, 2127-2131 (1994)]. The present experiment measured intensity discrimination and loudness enhancement in both forward and backward masking. A double-staircase adaptive procedure was used to match the loudness of a 30-ms, 1-kHz standard sinusoid presented in quiet to the loudness of a 30-ms, 1-kHz sinusoid presented 100 ms after (forward masking) or 100 ms before (backward masking) a 110-ms, 90-dB, 1-kHz masking sinusoid. The mean of the thresholds from the two staircases was used to determine the amount of enhancement, and the difference between the thresholds from the two staircases was used to determine the intensity just noticeable difference (jnd). Four listeners were tested at a range of standard levels between 30 and 90 dB. For all listeners, in both forward and backward masking, the jnd and loudness were greatest at mid-levels (40-70 dB). For a given listener, there was no substantial difference between the form of the results under forward and compared to backward masking, although there was considerable variability in the size of the effects between the individual listeners. Combining all the data, for both forward and backward masking there was a positive correlation between the size of the jnd and the magnitude of the loudness enhancement, although the correlation was only significant in backward masking (p < 0.005). Taken with the results of Zeng, these data suggest a link between loudness enhancement and the jnd increase, and a link between the mechanisms underlying the effects of forward and backward masking on intensity discrimination. It is suggested that all these effects may be caused by long-term loudness integration in the auditory system.