Decoding emotions from nonverbal vocalizations: How much voice signal is enough?

How much acoustic signal is enough for an accurate recognition of nonverbal emotional vocalizations? Using a gating paradigm (7 gates from 100 to 700 ms), the current study probed the effect of stimulus duration on recognition accuracy of emotional vocalizations expressing anger, disgust, fear, amusement, sadness and neutral states. Participants (n = 52) judged the emotional meaning of vocalizations presented at each gate. Increased recognition accuracy was observed from gates 2 to 3 for all types of vocalizations. Neutral vocalizations were identified with the shortest amount of acoustic information relative to all other types of vocalizations. A shorter acoustic signal was required to decode amusement compared to fear, anger and sadness, whereas anger and fear required equivalent amounts of acoustic information to be accurately recognized. These findings confirm that the time course of successful recognition of discrete vocal emotions varies by emotion type. Compared to prior studies, they additionally indicate that the type of auditory signal (speech prosody vs. nonverbal vocalizations) determines how quickly listeners recognize emotions from a speaker’s voice.