Previous research suggests that singers adjust their vocal production in response to different acoustic environments. This study investigated how virtual and real-room acoustics influence singers' vocal performance by analyzing vibrato rate, vibrato extent, and quality ratio. Ten classically trained singers performed an unaccompanied aria in three real performance spaces and their virtual replications under four sensory conditions: real, audio-only, visual-only, and combined audiovisual virtual reality (VR). Results showed that vibrato extent and vibrato rate were moderately affected by sensory condition, where larger values in some virtual conditions are compared to real rooms. However, the magnitude of these differences was within the range of just noticeable differences, suggesting that they may not be perceptually salient. perceived singing voice supportiveness, obtained from a survey, was significantly reduced in conditions lacking auditory feedback, underscoring the role of acoustic cues for singers. Overall, the findings suggest that VR-based auralizations can approximate the experience of real acoustic environments for singers' perceived and acoustic outcomes, although the effects on proprioception and voice support warrant further investigation. Given the small sample size, these findings are preliminary and should be confirmed in studies with larger singer populations.