ASSESSING THE INHERENT UNCERTAINTY OF SOUND IN- SULATION MEASUREMENT PROCEDURES: A NEW FRAME- WORK FOR VIRTUAL ROUND ROBIN TESTING

A framework for quantifying the combined effect of uncertain parameters in sound insulation assessment, such as test sample dimensions, damping loss factors, room properties, and loudspeaker positions, in a logically consistent way, has been recently developed [1]. In this contribution, the application of this framework towards virtual round robin testing - this means, computing the uncertainty of the sound insulation of a given building element that is inherent in a given standardized measurement procedure - is presented. Results are discussed for three walls for which the airborne sound insulation is determined in accordance with ISO 10140: a heavy calcium silicate block wall, a lightweight gypsum block wall, and a double glazing. The resulting uncertainty levels are very large, especially in the lowest frequency bands, and agree with experimental observations. A comparison is also made with the reproducibility values from ISO 140-2 and draft ISO 12999-1, which are based on a limited number of inter-laboratory experiments, and which should provide a rough indication of the uncertainty that can be expected.