What's this hole in my air intake?

[Yury]

I found this round hole on the intake tube which I can't make sense of.
Is it supposed to be there? It looks like a simple round drilled whole.

Seems kinda weird that engineers went through designing all the smooth ends and transitions for the air flow and just put a whole in the middle of it.





Coincidentally, when I apply throttle, at some point the intake sound goes from smooth purr to raspy.
And the gas mileage is unremarkable. It's not totally horrible, but not great either.

Anyone can see of their cars have the same hole? I am temped to tape it up with duct tape.

PS just looking at the pictures I noticed something that looks like a faint pencil mark near the hole...never noticed that before. Interesting.