Technical Booklet G Resistance to the Passage of Sound·Page 26·2.4
Wall type 1: Solid masonry
The sound resistance of solid masonry walls is determined primarily by the mass per unit area of the wall.
The resistance to airborne sound depends mainly on the mass per unit area of the wall.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet G - Resistance to the Passage of Sound.pdf