Emotional sounds elicit enhanced cortical responses in conditions of wakefulness. However, it is unknown whether this effect is similarly present during sleep. Even in deep sleep, evidence shows that the brain is not fully disconnected from its acoustic environment. On the other hand, sleep is characterized by an over-activation of limbic regions, related to emotion encoding, but by a hypo-activation of executive function regions, compared to wakefulness. In the present study, we examined event-related potential (ERP) responses to angry and neutral voices in 17 healthy subjects, both during wakefulness and sleep. We observed an early modulation of N1 auditory responses around 120-200ms post-stimulus in response to the emotional voices, compared to the neutral voices, only during wakefulness and rapid-eye-movement (REM) sleep. Furthermore, results showed a consistent modulatory effect by emotion across all awake and sleep (stage 2, 3 and REM) stages, around 500-600ms after-onset. These results demonstrate that emotion encoding and detection from external stimulation is preserved even in conditions of altered consciousness.