《科学美国人60秒》解读系列丨探测出声音的出现更重要

We know we can't hear everything in a busy area, or even in a quieter space. It's ultimately our attention that guides what sounds reach our conscious awareness. Think of the kids who can't hear the nagging parent.

But a new study finds another factor that determines if we can hear a sound: Whether that sound is appearing or vanishing.

Scientists asked participants to detect the onset or disappearance of different pure-tone sounds within soundscapes of ranging complexity. They found that listeners are really great at detecting new sounds but far less able to detect when a sound disappears. In fact they missed at least half of the changes when it involved a disappearing sound. This distinction remained within a range of soundscapes, from very simple to pretty complex.

我们都知道，人们不可能听见喧嚣地带的每一处声音，甚至在寂静的地方也是这样。最终，引导我们聆听的注意力会转变为意识知觉。这让我联想到听不见父母唠叨的孩子们。

但一项新的研究发现了另一个决定我们能否听到声音的因素：声音的出现或者消失。

科学家们要求被试者探测复杂性在一定范围内的音景中不同纯音的出现和消失。他们发现听者在探测新出现的声音时表现优异，在探测消失的声音时却感到困难。实际上，只要涉及到消失的声音，就会出现至少一半错误判断。这种区别在一定的音景范围内（从极其简单至相当复杂）一直存在。

- ultimately ['ʌltimitli]  adv. 最后，最终

- conscious ['kɔnʃəs] adj. 神志清醒的，意识到的，自觉的，有意的

- disappearance [.disə'piərəns] n. 消失

Researchers call this phenomenon "disappearance blindness." Interestingly, vision studies have found a similar advantage for objects that appear, as opposed to disappearing objects.

This study finds that ultimately the auditory system is not a “change” detector but rather a novelty detector. The researchers note that maybe detecting the appearance of new sounds, like a predator approaching or stranger in the night, is more important for survival than detecting when that sound has gone away.

研究人员把这种现象称为“消失盲区”。有趣的是视觉研究发现，出现的物体也具有类似的优势，消失的物体则相反。

这项研究发现，听觉系统终究不善于发现变化之音，而善于发现新奇之音。研究人员指出，对生存来讲探测出新声音的出现，例如捕食者接近或者夜晚陌生人出现的声音，都比探测出消失的声音更重要。

- phenomenon [fi'nɔminən] n. 现象，迹象，(稀有)事件

- novelty ['nɔvəlti] n. 新奇，新奇的事物，小装饰

- predator ['predətə] n. 食肉动物，掠夺者