Looking for suggestions on how to soundproof a stairs. I have am old timber stairs in a rented property. It runs by a dividing stud partition and an old very thin wall of concrete between the adjoining apartment .I have carpet on the stairs and tacked a foil/fabric material to the underside of part of the stairs. The main area is turning on the landing area where access is difficult. I might be able to access the turn area only from the apartment side where the original tongue and grove timber was slabbed .Are there any soundproofing beads that might be inserted here? Any suggestions?