Round Robin Test on Airborne Sound Insulation in Finland

Abstract

The Acoustical Committee of the Finnish Association of Civil Engineers RIL organized a round robin test on airborne sound insulation measurements in 2022. The test was participated by 15 measurement groups from 11 organizations and the test was carried out in an office building made of concrete. Airborne sound insulation between two office rooms separated by a plasterboard wall was measured horizontally in accordance with the standard ISO 16283-1 and single-number quantities were calculated according to the standard ISO 717-1. The participants determined independently apparent sound reduction indices R’ and standardized level differences DnT at one-third octave bands and calculated single-number quantities R’w and DnT,w as well as spectrum adaptation terms from their own results. The weighted apparent sound reduction index R’w was between 43 and 46 dB while the average was 44,5 dB and the standard deviation 0,7 dB. The weighted normalized level difference DnT,w ranged from 43 to 46 dB while the average was 44,8 dB and the standard deviation 0,9 dB. Compared to the standard uncertainties presented in the standard ISO 12999-1, the deviations of the results were larger in the frequency range from 1000 to 2000 Hz and at centre frequencies of 125 and 400 Hz.