The Effects of Visual Input in Virtual Reality on Voice Production: Comparing Trained Singers and Untrained Speakers

This study examined whether visual spatial cues presented in immersive virtual reality (IVR)-room size and speaker-to-listener distance-are associated with changes in vocal production, and whether these effects differ between trained singers ("experts") and untrained speakers ("novices").

Eight participants (four experts, four novices) completed speech tasks across eight IVR conditions presented in randomized order, manipulating room size (small, large) and speaker-to-listener distance (1 m, 3 m, and 15 m), as well as their combined conditions. Voice recordings were analyzed to extract sound pressure level (SPL; dB) and mean speaking fundamental frequency (f₀) (mean f₀: Hz), which were then examined using linear mixed-effects models.

For SPL, Listener Distance was significant and interacted with Group, indicating distance-dependent group differences. Experts showed significant within-group SPL differences across distance conditions, whereas novices demonstrated fewer significant distance-related contrasts. Room Size was not significant. For mean f₀, significant effects were observed for Group and Listener Distance, along with a Group × Listener Distance interaction. Follow-up contrasts indicated significant distance-related mean f₀ modulation within the expert group, whereas within-novice distance contrasts were not significant after Holm correction.

These preliminary findings indicate that visually specified speaker-to-listener distance influenced vocal intensity and mean f₀, whereas room size alone showed limited effects under acoustically controlled conditions. The results also suggest that vocal training may be associated with differential use of visual information, with experts demonstrating more flexible modulation across distance cues and novices showing comparatively limited adjustment. IVR was feasible for delivering controlled visual manipulations. Further work incorporating perceptual outcomes and more ecologically representative sensory feedback will help clarify underlying mechanisms and clinical significance.