Noise from My surface pro (2017)

[Antonht]

Hey. This is a rather random question, but I noticed today that when I charge my surface pro (2017) it almost sounds like liquid getting cooked while I hold my ear on the surface.

Is this just how batteries sound when they charge?

I googled and found no topic around this, so I figured out that this was the best place to ask.

It doesn't sound any particular otherwise, just when I placed my ear on the surface. (At the area where it gets hot)

 

[spicypadthai]

Probably coil whine, which is normal