Do You Hear What I Hear?|神秘的听音辨位

Do You Hear What I Hear?

by Jack Johnson

How humans and bats can sometimes be alike

Echolocation is a form of perception using sound. Bats are one of the most commonly known users of this ability. _(1)_ The signals fly out from the bats, and when they hit an object, such as a tree, a bird, or preferably, a tasty insect, they bounce back to the bats. _(2)_ Bats use the echoes from the sounds they produce to find what they're looking for, which is why it's called echolocation.

Other animals use echolocation as well. Dolphins are a good example. It might surprise you to learn of another creature that has been found to use echolocation, too--humans. _(3)_ One such person is a 16-year-old American boy, Ben Underwood. Ben is completely blind, and no traces of light can reach his brain. _(4)_ As he moves around the world, he makes clicking sounds to gain information about his environment. Interestingly, although people without sight can no longer gain visual knowledge from the world using their eyes, the section of the brain called the visual cortex does not become useless for them. _(5)_ As Underwood said in an interview, "I can hear that wall behind you over there. I can hear right therehe radio, and the fan." Through echolocation, Ben and others like him communicate with the world, and the world responds to the call.

 

(A) However, he has adapted to his blindness in an amazing way.

(B) When bats hunt in the dark, they emit sonar signals at very high frequencies and in very rapid bursts.

(C) For Ben, for instance, echolocation replaces the eyes in forming visual images in the brain.

(D) Not all humans have this ability, but a few have developed it as a skill to compensate for other physical limitations.

(E) Following the signals that bounce back to them, bats can narrow in on their prey and snatch it in midair.

(F) Bats are not generally aggressive and won't attack unless they feel threatened.

神秘的听音辨位

人类和蝙蝠有时会有什么共通点

回声定位是一种运用声音产生的知觉型态。蝙蝠正是这项能力的使用者中最广为人知的动物之一。蝙蝠在黑暗中猎食之际，牠们会发送高频而急促的声纳讯号。讯号从蝙蝠身上散发出去，当它们碰到物体，例如一棵树、一只鸟或者更棒的是，一只鲜美可口的昆虫，它们会反弹回蝙蝠身上。搜寻反弹到身上的讯号来源，蝙蝠就能锁定牠们猎物的所在范围，从半空中将之攫取入口。蝙蝠利用牠们制造的声音发出的回声来寻找锁定的目标，回声定位因而得其名。

其他动物也会使用回声定位。海豚就是一个很好的例子。不过你大概会很惊讶地发现另一种使用回声定位的生物  人类。并非所有人类都拥有此项能力，但少数人已将之发展为一种技能，以弥补其他生理上的限制。其中一位就是年仅 16 岁的美国少年  班‧安德伍。班双眼全盲，大脑无法感应任何一丝光线。然而，他却以一种神奇的方式适应了他的眼疾。当他移动的时候，他发出卡卡声来获取周遭环境的信息。有趣的是，虽然丧失视觉的人无法以眼睛获取周遭事物的视觉讯息，但大脑中的视觉皮层却不会失去其机能。打个比方，对班而言，回声定位取代了双眼，在大脑中产生了视觉影像。就如安德伍在一场访问中所言：『我可以听见你身后的那道墙。我可以听见那儿有收音机和电风扇。』透过回声定位，班和拥有类似情况的人能和世界沟通，世界也能响应他们的呼唤。

 

英国《星期日泰晤士报》曾报导，盲人的听力通常更加敏锐。有研究显示，经过培训，他们能利用听力解读回声，进而在脑中形成一系列详细影象，包括物体距离、大小甚至密度等。他们说，盲人借助手杖能确定路上的障碍物，而回声定位能让盲人『看到』周围 360 度的环境。经过培训后，盲人便能藉由听到回声时间来判断物体距离。透过这种能力，他们原本黑暗的世界变得更开阔。（数据源：教育部大专院校视障学生辅助中心）

答案： 1.   B   2.   E   3.   D   4.   A   5.   C