Feng Lei, Oxenham Andrew J
Department of Otolaryngology, University of Minnesota.
J Exp Psychol Hum Percept Perform. 2015 Dec;41(6):1696-708. doi: 10.1037/xhp0000115. Epub 2015 Aug 17.
A target sound can become more audible and may "pop out" from a simultaneously presented masker if the masker is presented first by itself, as a precursor. This phenomenon, known as auditory enhancement, may reflect the general perceptual principle of contrast enhancement, which facilitates adaptation to ongoing acoustic conditions and the detection of new events. Little is known about the mechanisms underlying enhancement, and potential confounding factors have made the size of the effect and its time course a point of contention. Here we measured enhancement as a function of precursor duration and delay between precursor offset and target onset, using 2 single-interval pitch comparison tasks, which involve either same-different or up-down judgments, to avoid the potential confounds of earlier studies. Although these 2 tasks elicit different levels of performance and may reflect different underlying mechanisms, they produced similar amounts of enhancement. The effect decreased with decreasing precursor duration, but remained present for precursors as short as 62.5 ms, and decreased with increasing gap between the precursor and target, but remained measurable 1 s after the precursor. Additional conditions, examining the effect of precursor/masker similarity and the possible role of grouping and cueing, suggest multiple sources of auditory enhancement.
如果掩蔽音先单独呈现作为前导音，那么目标声音会变得更易被听见，并且可能会从同时呈现的掩蔽音中“突显”出来。这种现象被称为听觉增强，它可能反映了对比增强这一普遍的感知原理，该原理有助于适应持续的声学条件并检测新事件。关于增强作用背后的机制我们知之甚少，而且潜在的混杂因素使得该效应的大小及其时间进程成为一个有争议的问题。在这里，我们使用两个单间隔音高比较任务（涉及相同/不同或上下判断）来测量增强作用与前导音持续时间以及前导音结束与目标音开始之间延迟的函数关系，以避免早期研究中潜在的混杂因素。尽管这两个任务引发的表现水平不同，可能反映不同的潜在机制，但它们产生的增强量相似。该效应随着前导音持续时间的缩短而减小，但对于短至62.5毫秒的前导音仍存在，并且随着前导音与目标音之间间隔的增加而减小，但在前导音之后1秒仍可测量。其他条件，即考察前导音/掩蔽音相似性的影响以及分组和提示的可能作用，表明听觉增强有多种来源。
