Engineering applications of active sound and vibration control

Engineering applications are the natural milestones where new technologies have to proof their potential and their perspectives. For active control of sound and vibration, this applicative justification was given in terms of specialised solutions for specific applications rather than as solution for widespread applications of large production number. This is in contrast to multiple ex­pectations and promises and reflects the persistent disadvantage of unviable implementation efforts. Thus, besides ongoing research progress, further and sustainable development and implementation work of some specialised engineering groups has helped to keep this hardly youthful approach attractive and promising. The paper reflects the applicative state of the art of active sound and vibration control and gives further evidence by three case studies for fully developed and practically applied engineering solutions. These case studies refer to the suppression of two self-excited sound field oscillations, wind-tunnel buffeting and combustion instabilities, and to active sound design, a way of extending the focus of sound field control to arbitrary target sounds in order to provide a flexible tool for in situ sound tests in the original environmental context. From such applications it can be expected that further improvements for all components involved including sensors and actuators will help to extend the applicative basis of active sound and vibration control.