Why is my Switch noisy when I charge it?

I've been playing Fortnite for half a year now. When I put on my headset to talk to my friends and at the same time charge my switch, they always say that it is noisy and it's a bit annoying, but I don't know why, when I mute the noise is gone

My switch makes noise when I start a game. But after a while it stops again. There may be some dirt inside the device that blocks the ventilation.

If you think you can, you can open it yourself and take a look.