What are the sounds from under the keyboard?

Question

Keyboard

Hello. Recently I noticed some kind of hissing sound from under the laptop keyboard on the left side . I found similar problems, everywhere they say that the cooler hisses, they say it is clogged, but I have a new laptop (less than a month old) and I noticed such a sound right away. He's so hissing-electric-buzzing or something.

Acer Nitro 5 2019 laptop, hisses on the left side, if you look at the laptop in disassembly, then in this part there are RAM and a
battery on the bottom left. (It's definitely not a hard drive that hisses, because it costs an M2 SSD)

Where do you think this whistle comes from and have you encountered this?