Do AAV's ever rattle?

[Jon_C]

I have a mainfloor bathroom and a basement bathroom. They are nowhere near each other and I only have one vent stack so I assume the basement bathroom is vented through an AAV. I have decent confirmation of this because the basement sink drain goes down and left toward the sewer, but also has another pipe going straight up where I assume the AAV is. They didn't put an access panel in the drywall. Here's my problem: When the mainfloor toilet is flushed I hear a rattling sound a few feet above the basement bathroom sink. This is the only condition that makes this happen, which seems really strange. Is it possible it's the AAV rattling, or is something else going on? It only happens in the first few seconds of flushing and then stops. I completely replaced the upstairs toilet (for other reasons) and it did not change this behavior.
I also thought it may be the supply lines rattling due to air so I turned off the main valve and drained the whole house starting and ending at the lowest point, but this didn't make a difference either.

 

[FullySprinklered]

The plan got changed on a job and I ended up installing a hand-wash sink on a very long trap arm. It was the food prep area in a convenience store. I mitigated the issue ( or so I thought) by installing a studer vent at the sink. It worked fine, but if you filled the sink and pulled the drain plug, you would get a fluttering sound. Like a hummingbird in a coffee can.