Design and Wizard-of-Oz Evaluation of a Tri-Modal Contactless In-Vehicle HMI for High-Noise and High-Vibration Cabins

Harsh cabins in mining, construction, and defense degrade touch human–machine inter- faces for secondary tasks, while single-modality contactless input stays fragile under coupled noise and vibration. A sequenced tri-modal protocol with dwell locking, head confirma- tion or cancellation, and optional voice refinement is specified and evaluated in a desktop Wizard-of-Oz browser under parameterized disturbance. An operator survey (N = 48) fixed timing constants; N = 30 participants compared touch (A), pooled single-modality contact- less (B), and tri-modal (C) under a fixed Hard preset. Holm–Bonferroni contrasts show C reduced error rate and NASA–TLX versus B (p <.01), shortened completion time versus B (p <.05), and improved SUS versus B, while A remained fastest with the lowest descriptive errors. Conclusions are interaction-level evidence under simulation, not ISO-calibrated cabin equivalence or production gaze or speech benchmarks.