Elephants, for example, talk with each other using infrasound– far below our human hearing range.

大象用远低于人类听觉范围的次声波唠嗑。

But this peacock is also making very loud infrasound with its tail, which you cannot hear, but female peahens can.

但这只孔雀与此同时也在用它的尾巴制造次声巨响，你是听不到的，但雌性孔雀可以听见。

At the other end, in the deep infrasound, elephants and whales, tigers and some birds make sound.

另一端的低频次声，大象、鲸鱼、老虎和一些鸟类会制造这样的声音。

Elephants do that. Rhinos do that. Hippos do that. Crocodiles do that. Alligators do it. They produce infrasound.

大象就会用次声交流，犀牛也会。还有河马，鳄鱼，短吻鳄。它们都能发出次声波。

Anything below that is called infrasound.

低于此的任何东西都称为次声。

So, that is how elephants use infrasound.

好了，这就是大象使用次声波的方式。

Hidden sounds, because much acoustic communication in nature occurs in the high ultrasound, above your hearing range, or in the deep infrasound, below your hearing range.

隐秘声音，是因为自然界中很多声音的交流都会在高频超声的频段，超过了你的听觉范围，或是在低频次声的频段，低于你的听觉范围。

But if it's hearing the infrasound grunts of a Triceratops, that's what it wants to hear, because that sound is gonna mean that's where lunch is.

但只要听到一点点三角龙的呼噜声它就高兴了，因为这呼噜声意味着午餐就在那里。