## In-situ/laboratory correlation for sound insulation over all barrier types

The diagram shows the correlation between the laboratory and the in-situ method for sound insulation over all barrier types available in the database. This correlation is based only on cases where both methods have been used for testing the same barrier. The frequency range where the data were available is specified for each method in the diagram title. In this case the coefficient of the linear regression indicates a very good accordance between the two methods. The formula of the linear regression is also shown in the diagram. Due to the relatively small number of cases for which results from both methods were available the linear regression cannot represent a robust relation for each barrier material separately. To establish such a relation more data would be needed.