When you understand a sentence I said you have to have the capacity to understand a sentence even if you've never heard it before.

当你在理解我所说的一句话时,你必须要拥有理解这句话的能力,即使你在之前从未听到过这句话

耶鲁公开课 - 心理学导论课程节选

Now it's possible somebody said both these sentences before, but you probably have not heard them.

有可能某人曾说过这两句话,可你们却并没听到过

耶鲁公开课 - 心理学导论课程节选

Now, when you listen to it then, again, knowing that, you hear it that way.

当你再次听到这句话时,你便知道,你是听到的是这个

耶鲁公开课 - 心理学导论课程节选