An Intercomparison of Laboratory Measurements of Airborne Sound Insulation of Lightweight Plasterboard Walls

Abstract

This paper describes the results of the European Inter-Laboratory Test (ILT) program, conducted for the determination of repeatability and reproducibility values for the laboratory measurements of airborne sound insulation of walls. A total of 24 laboratories took part in this ILT, 21 belonging to the European Community. Two test structures were constructed; a double lightweight wall and a single lightweight wall, both built of plasterboard. The sound reduction index values were measured. The main result of the ILT was the significant difference obtained for the reproducibility value, R, for the double lightweight wall with values up to 12 dB at middle-highfrequencies. On the contrary, the reproducibility value for the single wall was very similar to the tentative values indicated in Annex A of ISO 140-2. Good agreement between laboratories was found for both structures in the computed repeatability values, r.

Numerical Investigation of the Repeatability and Reproducibility of Laboratory Sound Insulation Measurements

“…The predicted standard deviations are lower than the ones corresponding to the repeatability values given in ISO 140-2 [21]. However, round robin tests [10] also indicated lower values, probably due to the automatic measurement procedures used nowadays. Furthermore, the theoretical model does not account for the uncertainty due to calibration errors or fluctuations in the sound field over time.…”

“…In general, the predicted standard deviations for the pressure method are larger the the ones corresponding to the reproducibility values given in the standard [21]. More recent round robin tests [10,1] also indicated a larger uncertainty at low frequencies. Furthermore, the wave based model considers the worst case with no diffusers in the rooms.…”

“…After the development of accurate sound intensity probes, the intensity method was elaborated as an alternative for the classical pressure method [9]. Experimental research into the reproducibility of sound insulation measurements has been continued with several round robin tests on lightweight and heavy walls [10,11,12]. Recently, the standards related to the pressure method were updated [13,14,15].…”

Poroacoustic acceleration waves in a Jordan–Darcy–Cattaneo material

“…Practical experiments on real scenarios are occupying many analyses, see e.g. Bonfiglio et al [1], Fausti et al [2], Garai and Pompoli [3][4][5], Pompoli [6], Prodi et al [7], Sakai et al [8], and reliable models which can account for experimental data are actively sought. In seismic areas such as the region near Avellino, close to Salerno, brick manufacturers are attempting to increase the porosity (the fluid to total volume ratio) thereby making the brick weigh less.…”

The repeatability and reproducibility of laboratory building acoustic measurements: Numerical study

“…Experimental research into the reproducibility of sound insulation measurements has been continued since with several round robin tests on lightweight and heavy walls. [8][9][10] Pedersen et al 1 proposed a new intensity method to improve the repeatability and reproducibility at low frequencies (50-160 Hz), which was incorporated in ISO 15186-3. 11 According to ISO 12999-1, 12 the reproducibility standard deviation of the pressure method increases from 2.1 dB at 200 Hz to 3.0 dB at 100 Hz and 6.8 dB at 50 Hz.…”