Sound isolation refers to the ability of construction assemblies to minimize the transmission of sound and isolate sound within its environment.  You may enjoy listening to your favorite band play, but your neighbors may find the “noise” to be unwanted.  Construction assemblies controlling sound isolation directly affect the quality of life of townhouse and condominium residents.  The distress resulting from poor sound isolation varies with the subjectivity of the unit occupants.  A change in neighbors can mean a big improvement or a sudden loss of acoustic privacy.  Because of the subjectivity of noise pollution, the standards are set to allow for ranges of tolerances.