Something Clicks for Dolphin Identification

海豚能用回声定位

Machine-learning algorithms teased seven distinct dolphin clicking patterns from a library of more than 50 million clicks, identifying one species by sound alone.

机器学习算法梳理出了海豚超过五千万种拍击中的七种模式，仅从声音就能判别种群。

撰文/播音 Christopher Intagliata 克里斯托福•因塔尔利亚他

翻译 张心茹

审校 张清越

Light doesn't travel well underwater. So dolphins and other toothed whales navigate like bats, using echolocating clicks. < >

光在水中不能良好地传播，因此海豚和其他齿鲸像蝙蝠一样利用拍击的回声定位导航。

"They're like lasers of sound they produce out of their forehead, and they bounce them off things the same way bats do, to interpret their environment."

“他们从前额发出的声音像激光，像蝙蝠发出的声音一样在周围反射，以此来了解四周的环境”

Kait Frasier is an oceanographer at the Scripps Institution of Oceanography. And her studies of underwater clicks include tossing computers, worth $100,000 dollars each, over the side of a ship, into the Gulf of Mexico.

凯特•弗莱瑟是斯克里普斯海洋学研究所（Scripps Institution of Oceanography）的一名海洋学家。她对水下拍击的研究动用了每台价值十万美元的计算机，她把计算机安装在船的侧面，伸入墨西哥湾的海域里。

"It just feels so wrong. But a year later you go back, you send out this little ping signal, it goes, doo doo doo doo doo, and that goes out to the instrument and it drops its weights and floats to the surface. And it's this magical moment, like 'I never thought we'd get that back.'"

“一开始感觉很不好。但一年后回来，发射轻微的信号后，嘟 嘟 嘟 ，这些声音传入仪器，它失重，浮出水面。这是一个神奇的时刻，我从未想过我们会看到它们回来。”

The waterproof computers have underwater microphones attached…. So when they float back up, they're loaded with a symphony of underwater sounds. Including more than 50 million clicks. < > And by the way that sample was slowed down by half, and lowered an octave.

这些防水电脑附带有水下麦克风……所以当它们浮起时，它们录满了水下声音组成的交响曲。包括了五千万中拍击声《拍击交响乐》同时这些样品减慢一半速度，降了八度。

Frasier used to comb through that audio, staring at the signals, trying to differentiate one from the other. "Yeah, more than i would like to spend my time sifting through."

弗莱瑟曾经梳理这些音频，观察这些信号，试图区分它们。“我不想把时间都花在整理它们上。”

So she set machine learning algorithms at the data instead… which sifted out seven distinct clicking patterns. And the algorithms were able to identify one species—called Risso's dolphin—by sound alone.  The results are in the journal PLOS Computational Biology. [Kaitlin E. Frasier et al., Automated classification of dolphin echolocation click types from the Gulf of Mexico]

所以她转而对数据设置了机器学习算法……筛选了七种不同的拍击模式。这个算法可以仅通过声音识别其中一个物种，里索海豚（Risso's dolphin）。这些结果收录于PLOS计算生物学杂志[Kaitlin E. Frasier et al., Automated classification of dolphin echolocation click types from the Gulf of Mexico]

Traditional marine mammal surveys scan surface waters from a boat, and extrapolate from there. But this tech might offer an alternative. "Instead of going out on a boat you put this instrument out, and it does this passive acoustic listening for a year, or many years in a row, and you can use that to get better time series of these animals over a long period of time."

If it can figure out how to tease out more individual species types, this survey method might really click.

传统的海洋哺乳动物研究只从船上搜索海面，然后根据水面结果推断。但这种技术或许提供了一种新思路。“除了驾船出海，你可以携带这个设备，它可以被动接收一年的音频信号，也可以是多年，然后你可以用它了解更长时间跨度内的动物行为时间。”如果它能解决如何梳理出更多的物种类型，这种研究方法将会真正“声”动学界。

—Christopher Intagliata