Preattentive auditory change detection relies on unitary sensory memory representations.

Event-Related potentials (ERPs) were recorded to series of frequent (standard) and three types of rare (deviant) tones differing from the standard in frequency, duration, or in both features. All deviants elicited the mismatch negativity (MMN) ERP component, indexing the deviation of a sound from the transient auditory memory trace of the standard. Duration deviance could be detected only after the offset of the duration deviant delaying the MMN to this deviant by 70 ms compared with the MMN of the frequency deviant. The MMN to the double deviant extended only to the latency range of the frequency MMN, revealing that feature-MMNs were coordinated by a memory trace integrating the outcome of the various feature analysers.