Precision of ISO 3382-2 and ISO 3382-3-A Round-Robin test in an open-plan office

International standards ISO 3382-2 and ISO 3382-3 are increasingly applied to determine the room acoustic conditions in open-plan offices because attention to noise control in such workplaces has increased. The precision of those standards in open-plan offices has not been published. The purpose of this study was to determine the precision of ISO 3382-2:2008 and ISO 3382-3:2012 in an open-plan office following the instructions of ISO 5725 standard. Furthermore, the results were analyzed in the light of ISO CD 3382-3:2020 involving improvements related to uncertainty. An accuracy experiment (a.k.a Round-Robin test, inter-laboratory test, intercomparison test) was arranged where nine independent participants conducted the measurements in the same open-plan office. For ISO 3382-3:2012, the reproducibility standard deviations were 0.5 dB, 1.3 dB, 1.3 dB, and 18% for spatial decay rate of speech (D-2,D-S), A-weighted SPL of speech at 4 m distance (L-p,(A, S,4m)), A-weighted SPL of background noise (L-p,L-A,L-B), and distraction distance (r(D)). The corresponding values for ISO CD 3382-3:2020 were 0.3 dB, 1.1 dB, 0.6 dB, and 16%, respectively. The reproducibility standard deviations for reverberation time were 4.5-16% within 1/1-octave bands 125-8000 Hz. The measurement uncertainty of ISO CD 3382-3:2020 is smaller than that of ISO 3382-3:2012. The values depended mainly on between-laboratory differences while within-laboratory differences had only a marginal impact. The results can be used in the development of the standards. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study aimed to evaluate the precision of ISO 3382-2 and ISO 3382-3 in open-plan offices, with results showing that the measurement uncertainty of ISO CD 3382-3:2020 is smaller than that of ISO 3382-3:2012. The experiments revealed reproducibility standard deviations for ISO 3382-3:2012 ranging from 0.5 dB to 18%, while for ISO CD 3382-3:2020, the standard deviations ranged from 0.3 dB to 16%.