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This is Scientific American 60-second Science, I'm Lucy Huang.

这里是科学美国人——60秒科学系列，我是露西·黄。

Mice and rats vocalize. To us, many of the sounds they make are ultrasonic¹—at too high a frequency to hear. But if we slow the calls down, they sound like squeaks³. And not all squeaks are the same. The sounds that rodents⁵ make when they are excited versus⁶ disappointed can be quite different.

小老鼠和大老鼠都会发声。对我们来说，它们发出的许多声音都是超声波——因频率过高而听不见。但如果我们将它们的叫声放慢，听起来就像是吱吱声。并不是所有的吱吱声都是一样的。老鼠在兴奋和失望时发出的声音可能截然不同。

For example, here's slowed-down audio of a rat drinking sugar water.

例如，这是大老鼠喝糖水时所发出声音的慢放音频。

(Rat squeak² clip)

（老鼠吱吱叫的声音）

But this rat (different squeak) got played—it got non-sweetened water after becoming accustomed to sugar water.

但这只大老鼠（不同的吱吱声）被耍了——在它习惯了糖水之后，研究人员给了它无糖水。

"Calls around 22 kilohertz are usually associated with unhappy affect and calls around 55 kilohertz are happy affect."

“约22千赫的叫声通常与不快乐的情绪有关，而约55千赫的叫声表明的是快乐情绪。”

John Neumaier, a professor of psychiatry⁷ and pharmacology at the University of Washington.

华盛顿大学心理学和药物学教授约翰·纽迈尔说到。

"So if you tickle⁸ a rat, it puts out a lot of 55 calls. If we give them a sucrose solution, then they put out a lot of calls at 55 kilohertz."

“因此，如果让大老鼠开心，它会发出很多55千赫的叫声。如果我们给它们蔗糖溶液，它们就会发出大量55千赫的叫声。”

Being able to interpret these different calls can help researchers understand the rodent⁴'s emotional state—which could affect the results of experiments on the animals.

能够理解这些不同叫声可以帮助研究人员了解老鼠的情绪状态，而情绪可能会影响动物实验的结果。

Of course, listening to rodents in real time eats up resources. To code one hour of a recording⁹,

当然，实时聆听老鼠的叫声会消耗资源。要为一个小时的录音编码，

"It takes 10 hours, you know, because you have to slow these recordings¹⁰ down in order to be able to listen to them."

“需要花费10个小时，因为必须放慢录音速度才能听见。”

To automate¹¹ the process, Neumaier's associates, Kevin Coffey and Russell Marx, used machine algorithms originally designed for self-driving cars to develop software that they call DeepSqueak. The program takes recordings of rodent squeaks and plots them by frequency and intensity¹². By transforming the audio to a visual representation,

为了实现这一过程的自动化，纽迈尔的同事凯文·科菲和拉塞尔·马克思使用了最初为自动驾驶汽车设计的算法，来开发他们称之为DeepSqueak的软件。该程序记录老鼠吱吱叫的声音，并根据频率和强度绘制图表。通过将声音转化为视觉表现，

"They were able to train the computer network to recognize what ultrasonic vocalization looks like and then to easily tell them apart from other kinds of noise."

“他们能够训练计算机网络识别超声波发声的样子，之后轻松地将其与其他种类的声音区分开来。”

The description of DeepSqueak is in the journal Neuropsychopharmacology.

他们对DeepSqueak软件的描述发表在《神经心理药物学》期刊上。

The researchers have made the software available to any other scientists working with rodents who could use this kind of analysis.

研究人员已将该软件开放给研究啮齿动物的其他科学家，他们可能会用到这种分析方法。

"In my mind it will democratize this kind of research so that people can afford to do it, because it's been a huge barrier."

“在我看来，这将使这类研究民主化，让人们能负担得起这种研究，因为这一直是巨大的障碍。”

(Squeak noises)

（吱吱叫的声音）

Thank for listening for Scientific American 60-second Science, I'm Lucy Huang.

谢谢大家收听科学美国人——60秒科学系列，我是露西·黄。