Inclusion Through Sound: A Systematic Review of Spatial Audio, Sonification, and Interaction Design in Immersive Technologies for Blind and Visually Impaired Users

Immersive technologies such as virtual and augmented reality increasingly depend on sound-based interaction. For blind and visually impaired (BVI) users, audio-first design has become not an enhancement but a requirement, enabling orientation, navigation, training, and equitable participation in environments that are otherwise inaccessible. This review synthesizes nearly 1,900 works retrieved from OpenAlex and Crossref through a reproducible Python-based pipeline, which was further refined through thematic classification into six major domains: spatial audio and head-related transfer functions (HRTFs), assistive technologies for navigation, sonification and auditory displays, auditory cognition, immersive system design and evaluation, and inclusive design frameworks. The analysis reveals that spatialized audio and multimodal interfaces consistently enhance presence and reduce workload, yet the field continues to face unresolved challenges, including the absence of scalable methods for personalizing HRTFs, the lack of unified evaluation standards for auditory interaction, and limited integration of accessibility frameworks into immersive design pipelines. This review provides an updated state-of-the-art synthesis, identifies underexplored questions, and highlights the necessity of embedding inclusion into immersive sound research. The methodological contribution of a transparent and extensible Python pipeline ensures the reproducibility of this review and establishes a foundation for ongoing meta-analysis in sound interaction and accessibility research.