Spatial auditory presentation of a partner's presence induces the social Simon effect

Social presence is crucial for smooth communications in virtual reality (VR). Current telecommunication systems rarely submit spatial auditory information originating from remote people. However, such information may enhance social presence in VR. In this study, we constructed a dynamic binaural synthesis system and investigated the effect of spatial auditory information of a remote partner on a participant's behavior using the social Simon effect (SSE). The SSE is a spatial stimulus-response compatibility effect between two persons. The SSE occurs when one perceives that their partner is present. Several studies have confirmed the SSE in actual environments. We presented partner sounds diotically (i.e., without spatial information) to one group or binaurally (i.e., with spatial information) to another group through headphones without providing visual information about the partner. The results showed that the SSE was induced only in the binaural group in the current auditory VR (Experiment 1), whereas both groups exhibited the SSE in an actual environment (Experiment 2). These results suggest that the auditory spatial information of remote people is sufficient to induce the SSE and has a potential to enhance social presence.