The applications of event-related brain potentials (ERPs) to the study of language are briefly outlined. Three studies of the effects of word repetition on ERPs evoked by spoken words are described. The results show that ERPs are sensitive to word repetition within-modality, but insensitive to variations in voice-specific acoustic features between first and second presentations. The studies also provide evidence that ERP repetition effects evoked by spoken words reflect both modality-and lexically-sensitive processes.