Emotion, voices and musical instruments: Repeated exposure to angry vocal sounds makes instrumental sounds angrier

The perception of emotion is critical for social interactions. Nonlinguistic signals such as those in the human voice and musical instruments are used for communicating emotion. Using an adaptation paradigm, this study examines the extent to which common mental mechanisms are applied for emotion processing of instrumental and vocal sounds. In two experiments we show that prolonged exposure to affective non-linguistic vocalizations elicits auditory after effects when participants are tested on instrumental morphs (Experiment 1a), yet no aftereffects are apparent when participants are exposed to affective instrumental sounds and tested on non-linguistic voices (Experiment 1b). Specifically, results indicate that exposure to angry vocal sounds made participants perceive instrumental sounds as angrier and less fearful, but not vice versa. These findings suggest that there is a directionality for emotion perception in vocal and instrumental sounds. Significantly, this unidirectional relationship reveals that mechanisms used for emotion processing is likely to be shared from vocal sounds to instrumental sounds, but not vice versa.