This is Scientific American’s 60-Second Science. I’m Pakinam Amer.

这里是科学美国人——60秒科学系列，我是帕基纳姆·阿默尔nP*mb&Jm,;CVehzK6F。

Clicks, clucks, grunts and snorts—these are not sounds that we typically associate with turtles.

咔哒声、咯咯声、咕噜声、哼哼声——我们通常不会把这些声音与海龟联系在一起4BwKIriaN8yru4eRf1hB。

They’re actually thought to be very quiet or even silent.

事实上，人们认为海龟非常安静，甚至寂静无声e-Usb0_hO[k7m%PN3Zga。

But it looks like we may have grossly underestimated how much sound they can make.

我们可能严重低估了它们能发出多少声音HFhVcwWu(VI。

Now a new study in Nature Communications has collected vocal recordings from 53 species of turtles and other animals that were otherwise considered to be mute.

现在《自然通讯》杂志上发表了一项新研究，该研究收集并录制了53种海龟的声音，以及其它被认为不会发声的动物的声音w]-G%baUwh;h&KkL!u。

Those clicks you’ve just heard were calls made by baby giant Amazon River turtles swimming together.

你刚刚听到的那些咔哒声是亚马逊河小海龟一起游泳时发出的声音o)|13tXwhz=1^&-rQ6。

A group of evolutionary biologists and other scientists in five different countries pored over these recordings and combined them with vocal repertoires of about 1,800 animal species from other studies.

来自五个不同国家的进化生物学家和其他领域的科学家仔细研究了这些录音，并将其与约1800种其他研究中的动物声音汇编结合起来rCUoTH)+0Qn(=d^。

They were able to piece together evidence that the last common ancestor of all lungfish and tetrapods started vocalizing more than 400 million years ago.

他们能够拼凑出表明所有肺鱼和四足动物的最后一个共同祖先在四亿多年前开始发声的证据geTNw9Iw-vrl3wYt(zSI。

(And just in case you aren’t familiar, tetrapods are four-limbed vertebrates that include amphibians, mammals, birds and reptiles.)

(以防你不熟悉，四足动物是指四肢发达的脊椎动物，包括两栖动物、哺乳动物、鸟类和爬行动物HB6dZ+0_Z60-YWq*kX!Q。)

That’s at least 100 million years earlier than previous studies had suggested.

这比先前研究认为的至少早了一亿年3SB!2qgU(c。

The new revelations amount to a rewriting of the acoustic history of animals with backbones.

这项新发现相当于改写了脊椎动物的声学史piv6bE,]J8^o。

I did fieldwork in the Brazilian Amazon with a researcher that published one of these first papers showing that turtles can communicate acoustically, and that inspired me.

我在巴西亚马逊地区和一位研究员一起进行了实地考察cb5[_U-=swWuW+5K7m。与我同行的这位研究员发表了这些早期论文中的一篇，论文表明海龟可以通过声音进行交流，这启发了我oR=zb+rU1c,%pa(f3Ja。

So I went back home, and I got a piece of equipment, and I started recording my own pets.

于是我回到家，买了一件设备，开始给我自己的宠物录音]GUmiNr#TNT;kOxvIY7J。

And I discovered that they were producing sounds as well, and the species I had were not known to produce sounds.

我发现我养的这个物种会发出声音，而它们会发出声音并不为世人所知6thfiwi!HfT4[=mDm6c。

So I started thinking maybe they all do, and I went out there, and I recorded as many as I could.

所以我开始思考，也许它们都会发声，于是我前往那里，尽可能多地录制了声音YaatHG_mNBeT^v)4!8%。