I need an emergency solution for this problem. The a/c vents in this old building are not insulated and the noise echoes through the entire place. I already talked to a building constructor to set up insulation of the walls but until then I would need a simple fix with stuff I already have. I tried a thick blanket and pillow before, but that didn't work so I am trying to find out if there are things I can put in front of that vent in my bedroom to mute the echo or break it!! I have a very noisy neighbor who is busy late at night--so for a temporary fix: what can I put in front of this vent? The guy won't be starting here until another 2 weeks to insulate my walls and I need to go to work in the mornings!!

Thank you in advance!!