The science of vibrations and waves in elastic media, in a narrower sense, the science of sound, its generation, propagation and reception. Subdomains are physical acoustics and electroacoustics. Where valves and, therefore also solenoid valves, are concerned, noise generation is a relevant and standardised factor required within the framework of construction physics (Institut für Bautechnik = Institute of Construction Engineering).

Part of a (closed-loop) control circuit which transforms the output signals of the control elements into a positioning command and executes this operation.