Uncertainty of facade sound insulation by a Round Robin Test. Evaluations of low-frequency procedure and single numbers

The uncertainty of facade sound insulation, in particular at low frequencies, was evaluated by a Round Robin Test, conducted in a full-scale experimental building at the Construction Technologies Institute of the National Research Council of Italy. Each of the 10 teams involved in the RRT replicated the tests 5 times, for a total of 50 measurements. The different measurement positions inside the receiving room were compared. In particular, all the teams involved in the RRT followed the low-frequency procedure, assessing corner and center room positions. It was found that the uncertainty of the low-frequency procedure is higher than that of the default procedure.