The Fraunhofer Institute for Building Physics (IBP) is to hold a symposium on January 20th 2015 in Stuttgart on the topic of “Loud Sports in Quiet Halls”. Acoustics, particularly in sports halls and indoor swimming pools, play a central role and have an influence on the atmosphere and people’s well-being. This is the subject of Ernst Ulrich Tillmanns’ lecture at the symposium in which he presents model solutions from the point of view of acoustics, design and economics. The aim of the symposium is to present a summary of the arguments and instruments involved in creating ideal acoustic conditions in sports halls and indoor swimming pools.