the Sound of Nails on a Chalkboard

I found this article at the site of Scientific American.
The title of the article is 'the Sound of Nails on a Chalkboard.'

I suppose that everybody knows this sound. And I believe everybody hates it. Who likes such kind of sound?

But I'm very surprised with the fact that there are people who research this sound. The researchers have to hear this sound during experiments. If I were them, I couldn't bare at all.
Why do they choose to research this sound? There are many things they could choose. Their choices are really mysterious to me.