Covert digital manipulation of vocal emotion alter speakers’ emotional states in a congruent direction

Significance We created a digital audio platform to covertly modify the emotional tone of participants’ voices while they talked toward happiness, sadness, or fear. Independent listeners perceived the transformations as natural examples of emotional speech, but the participants remained unaware of the manipulation, indicating that we are not continuously monitoring our own emotional signals. Instead, as a consequence of listening to their altered voices, the emotional state of the participants changed in congruence with the emotion portrayed. This result is the first evidence, to our knowledge, of peripheral feedback on emotional experience in the auditory domain. This finding is of great significance, because the mechanisms behind the production of vocal emotion are virtually unknown. Research has shown that people often exert control over their emotions. By modulating expressions, reappraising feelings, and redirecting attention, they can regulate their emotional experience. These findings have contributed to a blurring of the traditional boundaries between cognitive and emotional processes, and it has been suggested that emotional signals are produced in a goal-directed way and monitored for errors like other intentional actions. However, this interesting possibility has never been experimentally tested. To this end, we created a digital audio platform to covertly modify the emotional tone of participants’ voices while they talked in the direction of happiness, sadness, or fear. The result showed that the audio transformations were being perceived as natural examples of the intended emotions, but the great majority of the participants, nevertheless, remained unaware that their own voices were being manipulated. This finding indicates that people are not continuously monitoring their own voice to make sure that it meets a predetermined emotional target. Instead, as a consequence of listening to their altered voices, the emotional state of the participants changed in congruence with the emotion portrayed, which was measured by both self-report and skin conductance level. This change is the first evidence, to our knowledge, of peripheral feedback effects on emotional experience in the auditory domain. As such, our result reinforces the wider framework of self-perception theory: that we often use the same inferential strategies to understand ourselves as those that we use to understand others.