Efference copy

An efference copy is used to generate the predicted sensory input which estimates the (somato)sensory consequences of a motor command (top row). The sensory consequences of the executed motor command (bottom row) are used to compare with the corollary discharge to inform the CNS about external actions.
Efference copies as used in speech production: motor and auditory efference copies serve to allow for rapid comparison with motor and auditory consequences.