This study explored the temporal course of vocal and emotional sound processing. Participants detected rare repetitions in a stimulus stream comprising neutral and surprised nonverbal exclamations and spectrally rotated control sounds. Spectral rotation preserved some acoustic and emotional properties of the vocal originals. Event-related potentials (ERPs) elicited to unrepeated sounds revealed effects of voiceness and emotion. Relative to nonvocal sounds, vocal sounds elicited a larger centro-parietally distributed N1. This effect was followed by greater positivity to vocal relative to nonvocal sounds beginning with the P2 and extending throughout the recording epoch (N4, late positive potential/LPP) with larger amplitudes in female than in male listeners. Emotion effects overlapped with the voiceness effects but were smaller and differed topographically. Voiceness and emotion interacted only for the LPP, which was greater for vocal-emotional as compared to all other sounds. Taken together, these results point to a multi-stage process in which voiceness and emotionality are represented independently before being integrated in a manner that biases responses to stimuli with socio-emotional relevance.

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