PTE Re-tell Lecture 真实讲座练习题:海豚如何用声音来“看”

在PTE中,无论是Summarise Spoken Text 还是 Re-tell Lecture的考题大都是从真实的讲座或者演讲中截取的,中间经常经常夹杂很多不同的环境音.很多同学都反映有时未必是听不懂,而是听不到. 鉴于此,墨尔本文波雅思PTE专门为大家总结了真实讲座的PTE练习音频,相比新闻音频来说,整体更加接近PTE考试的真题,内容方面,我们也会为大家提供考试中存在的近似题,最近我们会持续更新,敬请期待!

When a dolphin is producing sound, just like bats do, it produces very narrow beam of sound, much like this…. So when you actually listen to some of the dolphin echolocation signals, so the dolphin echolocation signals we might not be able to actually hear individual calls, when a dolphin is producing a call, it actually just like a bat can pull out individual pulses, but to us, it sounds like buzzing…, but the dolphin just like the bat, its world is sped up much more than ours, so it can detect those individual pauses. And also just like a bat, it can focus its sound into very narrow beam of sound or of light. So let’s have that light beam now. All right, so if my lovely system over here is a dolphin, producing its narrowing beam sound. I am a fish that a dolphin wants to echolocate on. The dolphin produces very narrow, intense, loud beam of sound. And this is really good if you’re trying to detect a fish that’s a really far distance because it gives you a very strong echo coming back to that dolphin. But if I am a fish and the dolphin is getting closer to me, and I want to suddenly try to escape the dolphin, I can move out of the beam of that narrow sound and suddenly the dolphin cannot see me with it sound. So what does the dolphin do? Well the dolphin can actually change and can widen its beam of sound as it gets closer and closer to the fish. So that no matter where I am moving, if I am trying to escape the dolphin, the dolphin can still see me with the sound. So this is how the dolphin is changing its sound, much like how bats can change their sounds as well.


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