detecting an operating noise present in the system part continuously by a plurality of sensors disposed on the system part and being converted by the sensors into measurement signals;

storing the measurement signals in time intervals for a time range;

determining a first magnitude of a transform of each of the measurement signals with an aid of prescribed first parameters of a mathematical transformation rule in first time windows that are temporally sequential in first time steps and lie within the time range;

deriving a first evaluation function for each of the first time steps from the first magnitudes determined for each of the prescribed first parameters resulting in a plurality of first evaluation functions;

comparing the first evaluation functions respectively with a first threshold value, and an overshooting of the first threshold value by at least one of the first evaluation functions at a triggering instant is valued as an index for a presence of a pulse-type signal component indicating the mechanical effect;

determining second evaluation functions with an aid of prescribed second parameters of the mathematical transformation rule and with the same algorithms in second time windows that are temporally sequential in second time steps and lie within the time range, and which are smaller than the first time windows; and

determining the location of an effect from instants at which the second evaluation functions respectively fulfill a prescribed criterion, and from propagation time differences resulting therefrom.