人类回声定位仪的原理类似于蝙蝠的回声定位能力 This is Scientific American - 60 - Second Science . I ' m Christopher Intagliata . Many bats use a system similar to sonar to navigate in the dark .
They send out high frequency sound , sometimes as clicks , and get information about their surroundings by the timing and quality of the sound that bounces back .
And just as turning up the light in a darkened room helps to illuminate the objects there , bats are known to turn up the intensity of their clicks when they have trouble detecting a target .
Now , bats have had millions of years of evolution basically to sort of develop these mechanisms to dynamically adjust their emissions . Lore Thaler , a neuroscientist at Durham University in the U . K .
And what we were wondering is , well , do people do the same ? Because some people with impaired vision can indeed navigate using the echoes of finger snaps , hand claps , or mouth clicks .
But it ' s not known how dynamic that ability is . So Thaler and her team presented eight expert echolocators with a challenge :
could they tell whether a small dinner - plate - sized object was being held up about three feet from their head , by clicking alone ? You can try this at home by the way , with a plate or a book .
And if you hold it very close to your face while you ' re speaking you can notice that the sound that you hear really changes . But move the plate 45 degrees to the side . . . then 90. . . then behind your head . And the task gets harder .
But similar to the way bats do , the study subjects increased the number of clicks , and their loudness , as the object became harder to detect - perhaps as a way to amplify the weak sounds echoing back .
The subjects still had trouble detecting the object a full 180 degrees behind them - they did only slightly better than chance . But they guessed correctly 80 percent of the time when the object was diagonally behind them .
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