see people with them, and what happens here is it's supposed to be those noise cancellation headphones. All they do is they take in the ambient noise that's around it, and there's actually battery in the headphones, that then produces waves that are going to destructively interfere with that ambient noise.

我从来没有用过这个,但你会看到有人带他们,它们可以作为消噪音耳机,它们所做的就是采入,周围的随机噪声，耳机里面是，有电池的，然后它能产生和,随机噪声相干相消的声波。

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