When the ear of the mouse is stimulated with a tone burst of sufficiently long duration, a stimulus offset evoked potential is generated which mirrors, in some respects, the onset auditory brainstem response (ABR). The general waveform and interpeak latencies suggest this offset response is generated within the cochlea and auditory brainstem. But when visual detection threshold audiograms are made for these two responses, their shapes are not similar. The onset ABR thresholds reflect the behavioral detection thresholds, being lowest at midfrequency, while the offset thresholds are highest at midfrequency in the normal hearing CBA/J and RB3/bg mice. The LP/J mouse, with a mixed (conductive and sensory) dysfunction, shows a different relationship between its onset and offset thresholds. The onset- and offset-ABRs of the normal mouse also differ from each other in the slopes of their amplitude input-output functions.