VR360-SSL: Towards Accessible and Clinically-Viable 360° Sound Source Localization in Virtual Reality

Sound source localization (SSL) capability serves as a crucial indicator of early hearing impairment, with applications in hearing disorder diagnosis, hearing aid fitting, and neurodegenerative disease screening. However, traditional SSL testing requires expensive professional equipment (over $500,000) and dedicated soundproof facilities (over 30 m²), significantly limiting accessibility for large-scale screening programs. While VR-based systems offer a promising alternative, they face fundamental challenges when extending to full 360° scenarios, particularly severe confusion between front and rear sound sources and interaction fatigue for rear target selection. To address these limitations, we propose the VR360-SSL system, the first 360° VR-based screening and rehabilitation tracking tool. Our approach introduces a frequency domain enhancement strategy for non-individualized head-related transfer functions that perceptually compensates for front-back ambiguity by reinforcing high-frequency cues for front sources and enhancing low-frequency components for rear sources. We further incorporate adaptive interaction modalities (eye gaze and hand gesture) with pre-experiment assessment that matches interaction modes to users' VR experience and spatial imagination abilities. Preliminary experiments with 32 participants (including 23 normal hearing (NH) individuals and 9 single-sided deafness (SSD) patients) indicate that the system provides localization trends consistent with real sound field environments and successfully identifies performance gradients across different hearing impairment severities. Front-back confusion rates were significantly reduced to levels comparable with real-world medical setups. By reducing costs to a single VR headset, our system enables SSL testing expansion from specialized clinics to primary care and community-based screening scenarios, particularly suitable for VR-naive elderly populations and resource-limited areas.