Deviations from repetitive auditory stimuli evoke a mismatch negativity (MMN). Counterintuitively, omissions of repetitive stimuli do not. Violations of patterns reflecting complex rules also evoke MMN. To detect a MMN to missing stimuli, we developed an auditory gestalt task using one stimulus. Groups of six pips (50 ms duration, 330 ms stimulus onset asynchrony [SOA], 400 trials), were presented with an intertrial interval (ITI) of 750 ms while subjects (n = 16) watched a silent video. Occasional deviant groups had missing 4th or 6th tones (50 trials each). Missing stimuli evoked a MMN (p < .05). The missing 4th (−0.8 µV, p <.01) and the missing 6th stimuli (−1.1 µV, p < .05) were more negative than standard 6th stimuli (0.3 µV). MMN can be elicited by a missing stimulus at long SOAs by violation of a gestalt grouping rule. Patterned stimuli appear more sensitive to omissions and ITI than homogenous streams.