19 Acoutics
19.4 Masonry Walls and Demountable Partitions
Masonry
Masonry walls found in the conference rooms, which are plastered up at the top provide good air-borne sound insulation.
Sound waves consists of travelling groups of rapid pressure variations and when these flucations act on a wall they force it to vibrate. The movement of the wall, however imperceptible, acts on the surrounding air in exactly the same way as a loudspeaker and sound is transmitted into adjoining rooms. The technique of air-borne sound insulation, therefore, is to reduce the transmission by providing a wall which will not move easily. Masonry walls possess that property, as brick plastered masonry units can provide an insulation of up to 55dB.
Demountable Partitions
Demountble partitions are used in the lecture rooms. The formed panels of 400mm side are fitted into slots of formed steel studs, where they are jeld in place by spring action. The studs are held at the top and bottom by tracks which are secured by appropriate fastenings to the underside of a structural floor. Individual panel can be removed or replaced without distortion. Sound transmission through this type of partition can be reduced by placing insulation batts between the outer panels.
