This document specifies a method to determine the apparent speech level reduction of furniture ensembles and enclosures (hereinafter referred to as test objects) in field conditions meeting engineering grade of accuracy.

The method is applicable to furniture ensembles or enclosures, which can be used by one or more occupants.

This method is not intended for single components used in workstations, such as a screen, a storage unit, a table, a luminaire, a cupboard, a bookshelf, a standard chair, a wall absorber, or a ceiling absorber.