This study aims to clarify the role of sound in evoking the sublime experience within a virtual reality (VR) environment. The sublime is a complex emotion combining awe and fear, arising from vast objects or overwhelming forces. VR is considered an effective medium for safely inducing this experience. However, existing research has predominantly focused on visual factors, and the influence of auditory stimuli—essential for immersion—remains insufficiently explored. In this study, a 3D 360° video of a volcanic crater was presented via a head-mounted display (HMD) under three auditory conditions: Silent, Normal (natural environmental sound), and Reverbed (processed sound). We evaluated the experience using subjective measures (Awe Experience Scale) and objective physiological measures (Electrodermal Activity, pupil diameter, gaze data). The results demonstrated that the presence of sound significantly amplified the sublime experience across both subjective and objective indices. Specifically, the Normal condition showed high integration with visual information, eliciting the strongest emotional arousal and significant pupil dilation. Conversely, while the Reverbed condition induced spatial exploratory behavior (gaze dispersion), it caused a sense of incongruence between sight and sound, tending to lower the quality of the experience. These findings suggest that audio-visual congruence is critical in designing sublime experiences in VR.