Abstract: The invention relates to a device for the verification of time-dependent, user-specific signals which includes means for generating a set of feature vectors which serve to provide an approximative description of an input signal and are associated with selectable sampling intervals of the signal; means for preparing an HMM model for the signal; means for determining a first probability value which describes the probability of occurrence of the set of feature vectors, given the HMM model, and a threshold decider for comparing the first probability value with a threshold value and for deciding on the verification of the signal.