scope:

Specifies a laboratory method to measure the airborne and impact sound insulation of an access floor with a plenum of defined height mounted below an acoustical barrier which separates two rooms of a specified test facility. This method utilizes a laboratory space arranged in such a manner that it simulates a pair of horizontally adjacent, typical offices or rooms sharing a common access floor system, plenum space and a dividing wall. The dividing wall extends from the ceiling to the upperside of the floor system which at the junction is either continuous or discontinuous. The quantities being measured are the airborn and impact sound insulation between two rooms of a specified test facility when the sound transmitted by paths other than the access floor and common plenum space is negligible. These quantities are called the normalized flanking level difference and the normalized flanking impact sound pressure level. The method can be extended to the study of the additional sound insulation that can be achieved by auxiliary systems, such as material used either as plenum barriers or as backing for all of, or part of the floor.