The objective in this project is to present a method for quantifying the diffusing effect of furniture and other equipment in rooms with ceiling treatment. The presence of furniture and equipment in this type of rooms will influence room acoustical parameters such as reverberation time, speech transmission index and sound pressure levels among others. A measure denoted equivalent scattering absorption area is introduced. The measure quantifies the scattering effect of objects in the room and is analogue to the equivalent absorption area used in Sabines formula.
A laboratory method for measuring the equivalent scattering absorption area is developed. Measurement results for typical classroom furnishing are presented.