Mismatch negativity--the measure for central sound representation accuracy.

The mismatch negativity (MMN), elicited by any discriminable change in a repetitive sound even when this sound is not attended to, provides a pre-perceptual physiological measure of the accuracy of the central sound representation in the human brain. This accuracy, which can be measured separately for the different features of the sound, determines the individual's sound discrimination accuracy in normal and various pathological conditions.