Self-ownership, not self-production, modulates bias and agency over a synthesised voice

Voices are fundamentally social stimuli, and their importance to the self may be underpinned by how far they can be used to express the self and achieve communicative goals. This paper examines how self-bias and agency over a synthesised voice is altered when that voice is used to represent the self in social interaction. To enable participants to use a new voice, a novel two-player game was created, in which participants communicated online using a text-to-speech (TTS) synthesised voice. We then measured self-bias and sense of agency attributed to this synthesised voice, comparing participants who had used their new voice to interact with another person (n = 44) to a control group of participants (n = 44) who had been only briefly exposed to the voices. We predicted that the new, synthesised self-voice would be more perceptually prioritised after it had been self-produced. Further, that participants' sense of agency over the voice would be increased, if they had experienced self-producing the voice, relative to those who only owned it. Contrary to the hypothesis, the results indicated that both experimental participants and control participants similarly prioritised the new synthesised voice and experienced a similar degree of agency over it, relative to voices owned by others. Critically then, being able to produce the new voice in a social interaction did not modulate bias towards it nor participant's sense of agency over it. These results suggest that merely having ownership over a new voice may be sufficient to generate a perceptual bias and a sense of agency over it.