Abstract: A signal is processed for recognize an irregularity in the signal. First, an orthogonal imaginary signal corresponding to the signal to be processed is formed. This is followed by a transformation step, which is then followed by a differentiation step. The signal thus processed shows the irregularity particularly clearly, so that the irregularity can be isolated, selected and detected. Preferred fields of application for the present method and corresponding devices are in the medical field, information technology, and signal treatment in network engineering, in particular low, medium, and high voltage engineering.