This is Scientific American 60 Second Science. I'm Lucy Wong.

Myse and Rats vocalize. To us, many of the sounds they make are ultrasonic, at too higher frequency to hear. But if we slow

the calls down, they sound like squeaks. And not all squeaks are the same. The

sounds that rodents make when they're excited versus

disappointed can be quite different. For example, here's slow down audio of a

rat drinking sugar water. But this rat got played. It got non-sweetened water

after becoming accustomed to sugar water.

Calls around 22 kilohertz are usually

associated with unhappy affect and calls around 55 kilohearts are happy effect.

John New Meyer, a professor of psychiatry and pharmacology at the University of Washington.

So if you tickle 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.

Being able to interpret these different calls

can help researchers understand the rodent's emotional state, which could affect the results of the experiments on the animals.

Of course, listening to rodents in real time eats up resources.

To code one hour of a recording, it takes 10 hours, you know, because you

have to slow these recordings down in order to be able to listen to them.

To automate the process, New Myos Associates, Kevin Coffey, and Russell Marks used machine algorithms

originally designed for self-driving cars to develop a software that they call deep squeak.

The program takes recordings of the rodent squeaks

and then plots them by frequency and intensity.

...