Machine acoustics at TU Darmstadt - history, present topics, and future developments

This paper will start with an overview of the historical development of the research and science of machine acoustics at Technische Universität Darmstadt, Germany, in the 1960s, 1970s, and 1980s. Back then the physical noise generation mechanisms of gears, gearings, and axial piston pumps were thoroughly investigated and analyzed for the first time, the "fundamental equation of machine acoustics" was developed, and measures for engineering noise control "at the source" were derived. In addition, the paper will present some recent examples and project results from current research projects. Finally, some trends for research activities in the future will be pointed out. These include the numerical simulation and experimental measurement of vibrational energy flow in solid structures, the increasing use of active methods, the combination of machine acoustics and psychoacoustics (What makes a machine noise more pleasant? How can a good and recognizable product sound or even a brand sound be generated? How can psychoacoustic metrics be incorporated into active control concepts? EL), and the combination of methods for reliability assessment and machine acoustics (structure and damage monitoring, reproducibility of acoustic measurement results, quality control by means of acoustic emission measurements, etc.).