Uncertainty of façade sound insulation in buildings by a Round Robin Test

Multilevel Functional Principal Component Analysis of Façade Sound Insulation Data

“…Moreover, the between variance and the total variance both have a local maximum at 1163.6Hz. In the first analysis of this dataset, a high between‐laboratory variability was observed at the 1250‐Hz one‐third octave band, corresponding to the critical frequency of the shutter box. To the best of our knowledge, there is only one other work dealing with an RRT on façade sound insulation .…”

“…From the acoustic point of view, a possible explanation for the high values at the lowest frequencies (i.e., the 50‐, 63‐, and 80‐Hz one‐third octave bands) could be found in the presence of the normal vibration modes, which are orthogonal to the propagation direction of the wave. For a room of the size of the receiving room, the analysis of these modes of vibration confirms that, at the first three one‐third octave bands, the measured levels can be strongly influenced by the microphone position.…”

“…Each team was coordinated by ITC‐CNR but used its own procedures and equipment. However, a laboratory that showed a significant presence of stragglers and outliers in a previous analysis was excluded.…”

“…Consequently, in the pointwise analysis, we observe a sharp increase of the estimated variances from 50 to 63Hz. This behavior, which is difficult to interpret from an engineering point of view, is mitigated by the smoothing effect of the functional framework.…”

“…‡ ‡ This study is based on a research conducted in a full‐scale experimental building at the Construction Technologies Institute of the National Research Council of Italy (ITC‐CNR) sponsored by the Lombardy Region …”