Our ability to discriminate and recognize human voices is amongst the most important functions of the human auditory system. The current study sought to determine whether electrophysiological markers could be used as objective measures of voice familiarity, by looking at the electrophysiological responses [mismatch negativity (MMN) and P3a] when the infrequent stimulus presented is a familiar voice as opposed to an unfamiliar voice. Results indicate that the MMN elicited by a familiar voice is greater than that elicited by an unfamiliar voice at FCz. The familiar voice also produced a greater P3a wave than that triggered by the unfamiliar voice at Fz. As both the MMN and the P3a were elicited as participants were instructed not to pay attention to incoming stimulation, these findings suggest that voice recognition is a particularly potent preattentive process whose neural representations can be objectively described through electrophysiological assessments.