Designing for Comfort in VR Public Speaking: How Avatar Realism and Natural Environments Shape User Experience and Stress Responses.

Virtual reality (VR) is increasingly used in public speaking training, yet the distinct roles of environmental context and virtual audience design remain unclear. This study examines how avatar visual style (realistic vs. stylized) and scene type (natural vs. indoor) influence subjective experience and physiological stress. A total of 132 participants were assigned to a 2 × 2 between-subjects experiment. Subjective experience was assessed using standardized questionnaires, while physiological responses were measured via electrodermal activity and heart rate variability, complemented by post-experiment interviews. Results revealed a dissociation between subjective and physiological responses. Natural environments significantly enhanced user satisfaction and overall experience, whereas avatar style primarily influenced physiological stress. Specifically, stylized avatars elicited lower electrodermal activity than realistic avatars, indicating reduced sympathetic arousal. No significant interaction effects were observed. Mediation analyses showed no significant roles of perceived support or threat, suggesting that physiological responses may not rely on explicit cognitive appraisal. Qualitative findings further indicated that ambiguous audience feedback limited evaluative interpretation. These findings support a dual-pathway framework in which environmental context shapes cognitive-affective experience, whereas avatar realism modulates implicit physiological stress. This study provides theoretical insights and practical implications for designing VR systems that enhance user comfort and reduce stress.