Sound Insulating Swellings: People are most often distributed by road traffic noise , aircraft noise or noise from nearby industrial premises, when they are in their own homes. If the disturbance occurs during the evening or night homes, then probably people are at their most sensitive to noise as well. If every one lives in a cavity wall beick structure containing no windows, doors, airbricks, roof joistsor, fireplace, they can count upon average sound insulation's od 50 dB(A). The physical characterstics needed foe a wall to offer good transmission loss are (i) that the wal should be made from nonporous dense meterial and (ii) that there should be no flanking paths. Sound reduction offered by a wall increase withits mass. This is called Mass Law.
Possible options and procedures for controlling noise indoors and outdoors are summerized in figure-2 (below).