DIN 4109 refers to the series of standards DIN 52210 with regard to the verification methods and necessary testing of acoustics in buildings. When the series of standards DIN EN 20140, DIN EN ISO 140 and DIN EN ISO 717 are published they will replace the series of standards DIN 52210. The practical application of the European standards has led to some difficulties in connection with the tests specified in DIN 4109 because some of the specifications given in DIN 52210 have not been included in the European standards, e. g. the verification of sound insulation by quality and suitability testing. This supplement includes regulations and such specifications of the withdrawn DIN 52210 which have to be applied in addition to the above-mentioned European standards on the national level in order to ensure a uniform proceeding in conformity with DIN 4109 when testing the acoustics in buildings in accordance with DIN 4109 (quality and suitability testing).