Hearing anger in someone’s voice, most of us would instinctively shrink... but how much do we respond to the emotional tone of our own voices? A digital audio platform that alters emotional inflection has revealed a feedback loop between our voice and our moods: We align our feelings with the emotional sounds we hear, researchers say.

Dr. Jean-Julien Aucouturier of the French National Centre for Scientific Research has placed a great deal of effort into cracking the psychological and emotional codes underlying sound. Among his many projects, Aucouturier is attempting to understand how different sounds trigger different feelings. Ultimately, he and his colleagues want to build a bank of sounds that are engineered to activate specific neuronal pathways in the brain. From this sound bank, the team hopes to create musical alternatives to replace the current pharmacological therapies that treat depression, anxiety disorders, and other mental distress.

Now he is combining neuroscience, computer science, and musical knowledge to analyze vocal frequencies related to feelings in order to create "emotional" sounds using special effects such as vibrato. For the study, he and his colleagues began with the understanding that we try to manage and control our emotions. In a heated situation, for example, we might maintain a poker face, hiding our real feelings while we reappraise. So Aucouturier and his colleagues designed an experiment to investigate the awareness, if any, we have of our own emotional expressions.

Using a unique digital audio platform, participants read a short story aloud while hearing an altered version of their voice, either sounding happier, sadder, or more fearful, through a headset. To manipulate participants’ voices, digital audio processing algorithms simulated acoustic components of vocalizations. The happy manipulation, for example, altered the pitch to make the voice sound more positive, changed the dynamic range to make the voice sound more confident, and filtered the spectral content to make the voice sound more excited.

Importantly, the participants were unaware their voices were being manipulated. Observing them as they read, the research team came to some surprising conclusions.

Life Imitates Voice

Participants changed their emotional state to align with the feelings portrayed by their manipulated voice. According to the researchers, this suggests we do not always control our voices to meet a specific goal; instead, we listen to our voices to learn what we feel.

“The relationship between the expression and experience of emotions has been a long-standing topic of disagreement in the field of psychology,” said co-author Petter Johansson, of Lund University in Sweden, who has conducted previous studies examining this matter.

Co-author Katsumi Watanabe of the University of Tokyo believes the platform could be used for therapeutic purposes. By re-describing negatively charged events in a modified tone of voice, the tool might induce a positive mood change in a patient suffering from anxiety.

The research team has made their real-time voice transformation tool available here. DAVID (Da Amazing Voice Inflection Device), which is able to “color” any voice recording with an emotion that wasn’t intended by its speaker, was developed by Dr. Marco Liuni and named after David Byrne of the Talking Heads.

Source: Aucouturier JJ, Johansson P, Hall L, et al. Covert digital manipulation of vocal emotion alter speakers' emotional states in a congruent direction. PNAS. 2015.