It's just you.
The sound generator is a sealed diaphragm inside the "can". There is no air passing through the tube from the intake to the cabin so there is nothing being injected into your passenger cabin. The reason I know this is because I was examining the can after I removed the sound generator. While examining the parts, I noticed that Subaru labeled the can part of it "DAMPER". Looking inside as best as I could, I could see that the interior wall is like a rubber accordion material. Then I also noticed that the intake side of the DAMPER is the exact size of the other end of the hose and it would fit directly into the intake tube.
Soooooo...
It got me wondering, would mounting the can directly to the intake tube quiet the intake even more/better than just having the resonator chamber at the bottom of the intake tube? Or better yet, will it tune the intake for better response/power? Or is it just a coincidence? Or did Subaru intentionally do it to waste my time?
Has anyone tried it? If so, did it change anything?
I plan to mount it up there just for the heck of it. Unfortunately, I don't have access to a dyno to see if it makes any measurable difference...