Department of Cognitive Sciences, University of California, Irvine, California 92697-5100, USA.
J Acoust Soc Am. 2012 Jan;131(1):386-97. doi: 10.1121/1.3664081.
In a concurrent profile analysis task, each of the two observation intervals was the sum of two harmonic complexes. In the first interval one of the harmonic complexes had a flat spectrum and the other had a broad spectral peak at 1 kHz. In the second interval, the association between the spectral profiles and the complexes was either consistent with the first interval, or inconsistent so that profile changes (flat versus peaked) could be created in both of the complexes. In two experiments, thresholds and psychometric functions for detecting the profile change were measured in terms of the spectral peak's magnitude as functions of three types of segregation cues: Difference in fundamental frequency, onset asynchrony, and difference in interaural time difference between the two complexes. Decreasing the magnitude of each cue led to higher thresholds, and shallower psychometric functions whose upper asymptotes often failed to reach 100% correct. The patterns of the threshold and psychometric functions varied across cue types and across individual listeners. The results suggest that informational masking is present in the concurrent profile analysis task. Segregation cues appear to contribute to the release from informational masking, but the process depends on listening strategies adopted by individual listeners.
在同时进行的轮廓分析任务中，两个观察间隔中的每一个都是两个谐波复合体的总和。在第一个间隔中，一个谐波复合体的频谱是平坦的，而另一个在 1 kHz 处有一个宽的谱峰。在第二个间隔中，频谱轮廓与复合体之间的关联要么与第一个间隔一致，要么不一致，从而可以在两个复合体中都产生轮廓变化（平坦与峰值）。在两项实验中，根据频谱峰值幅度，以三种分离线索的形式测量了检测轮廓变化的阈值和心理物理函数：基频差、起始异步和两个复合体之间的耳间时间差的差异。每种线索的幅度减小都会导致阈值升高，以及心理物理函数变浅，其上限通常无法达到 100%的正确率。阈值和心理物理函数的模式因线索类型和个体听众而异。结果表明，信息掩蔽存在于同时进行的轮廓分析任务中。分离线索似乎有助于从信息掩蔽中解脱出来，但该过程取决于个体听众采用的聆听策略。
