Synthetic speech and affective experience in virtual reality: A scoping review

Aims: This scoping review systematically maps the existing literature at the intersection of virtual reality (VR), synthetic speech, and affective computing. As immersive and voice-based technologies gain traction in education, mental health, and entertainment, it is critical to understand how synthetic speech shapes emotional experiences in VR environments. The review clarifies how these concepts are defined, how they contribute to empathic computing, and identifies common applications, methodological approaches, research gaps, and ethical considerations. Methods: A comprehensive search across multiple databases (e.g., ACM Digital Library, IEEE Xplore, ScienceDirect) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) framework. Eligible studies investigated synthetic or computer-generated speech in VR or comparable immersive 3D settings and assessed emotional responses or related outcomes. Data were extracted on study characteristics, applied technologies, affect-related measures, and reported effects. Results: The findings reveal a growing interdisciplinary body of research at the convergence of synthetic speech technologies, embodied virtual agents, and affective data processing in immersive environments. Interest in this area has accelerated with the development of advanced text-to-speech models, suggesting increasing relevance and expansion of this topic. Conclusion: This review underscores a rapidly expanding yet fragmented research landscape. It highlights conceptual and methodological gaps, stressing the need for clearer definitions, standardized evaluation measures, and ethically informed design of synthetic speech in VR. The results provide a foundation for advancing research and applications in emotionally responsive virtual environments.