With the revision of DIN 4109 "Sound Insulation in Building Construction" in July 2016, the legal minimum requirements for sound insulation have been redefined. This manual provides an overview of the history of the standard and its interaction with other guidelines and regulations. The essential passages of the individual parts of the standard are commented on and illustrated with practical cases and examples. The compendium contains comprehensive information on the application and interpretation of DIN 4109, including verification procedures, calculation models, as well as the consideration and evaluation of testing and measurement methods.