Hello, I've come in search for an answer for what's going on.

There's a squeaking noise in what I'm assuming is an air vent above the exhaust hood/range hood in the kitchen of my new apartment. I don't recall hearing it when I was there previously. When I first noticed it, I thought it was a bunch of birds chirping but as I listened closer, it sounded more like squeaking. The wall that the vent(?) disappears into is shared with the toilet (as in the toilet is on the other side). The sound got louder sometimes, softer other times and it went away completely for a little bit too. Initially, I thought it was something related to the water (since the building is older) but that doesn't seem to be the case from what I can tell. The kitchen was remodeled about ten years ago. The exhaust hood was off when I noticed the sound. I tried turning it on and then off again but that didn't do anything.

Is anyone familiar with this kind of issue? I would like to understand what's going on so I can contact the person who can fix it right away instead of searching everywhere first. Thank you.