The human auditory pre-attentive change detection system indicated by the mismatch negativity component (MMN) of the event-related brain potential is known to be sensitive for the successive presentation of tones deviating in frequency. The present study investigated deviance-repetition effects as a function of the feature defining deviancy, the type of the second deviant (bearing a different vs. the same feature value as compared to the first deviant) and the stimulus-onset asynchrony (SOA). Using the features frequency or location for defining deviancy MMNs elicited by the second of two successive deviants were reduced significantly. However, the reduction of MMN-amplitude is markedly smaller if the second of two successive tones deviates in a different feature value (e.g. a right localized deviant is followed by a left localized deviant) as compared to if the second deviant bears the same feature value as the first deviant (e.g. a right localized deviant is followed by a right localized deviant). The variation of SOA across the temporal window of integration did not influence the deviance-repetition effects. It is argued, that the pre-attentive change detection system evaluates the informational content of the succession of deviants enabling an effective scanning of the auditory environment for potentially relevant events.