This randomized non-inferiority trial compares Nature Soundscape Immersion (NSI) with Virtual Reality (VR) for reducing preoperative anxiety in adults undergoing elective surgery. Both interventions lowered anxiety significantly, with NSI proving non-inferior, offering greater stress reduction, and causing far fewer adverse effects than VR. The study highlights NSI as a low-cost, scalable, and highly feasible psychological prehabilitation tool for high-volume perioperative settings.