Effects of simulated bobbing and step sounds on cybersickness and presence in virtual reality

Based on a previous study that identified the importance of vertical oscillation and lateral rotation in simulating natural bobbing movements in virtual reality (VR), this study employed two psychophysical experiments to evaluate the impacts of the bobbing mechanism in more dynamic virtual environments. Experiment 1 investigated forward-only movement in VR, assessing whether simulated bobbing and step sounds could mitigate cybersickness and enhance presence. The experimental results revealed that while simulated bobbing alone did not significantly reduce cybersickness, the addition of bobbing and step sounds could improve the sense of presence. Experiment 2 extended the scope to unconstrained movement in all directions (on the ground only), examining how increased disorientation and postural instability affect cybersickness and presence. Results showed that unconstrained movement led to higher levels of cybersickness, particularly at higher velocities of movement in VR, and that simulated bobbing seemed to mitigate some level of cybersickness during running. Sex differences were observed, with female subjects showing greater susceptibility to cybersickness but benefiting more from the simulated bobbing during running. Additionally, variations among subjects highlighted the importance of personalised adjustments to enhance VR experiences.