This Guide addresses flanking transmission of sound through wood framed construction. Continuous structural elements at the junction of a partition wall and floor provide a transmission path by-passing the separating partition between two noise-sensitive spaces. Flanking transmission is sound transmission between two rooms by paths other than directly through the nominally separating wall or floor assembly.Flanking exists in all buildings and its importance in determining the apparent sound insulation (that perceived by the occupants) depends on of the construction details of the walls, the floors and their junctions.
National Research Council of Canada
Research Report (National Research Council of Canada. Institute for Research in Construction), no. RR-193 (1 March 2005).