Electric-Vehicle Gearbox NVH Research Map: An Integrative Synthesis of Manufacturing Variability, Transmission Error, Structural Acoustics, Machine Learning, and Psychoacoustics

This preprint integrates seventeen previously published studies into a unified research map for electric-vehicle gearbox noise, vibration, and harshness (NVH). The synthesis connects manufacturing and assembly variability with transmission-error-related excitation, dynamic transfer paths, gearbox housing response, acoustic radiation, condition monitoring, machine-learning-based assessment, and psychoacoustic perception. The principal contribution is an integrated evidence chain linking physical variability, excitation generation, dynamic transfer, structural-acoustic response, perception, and production feedback. Four simulation-readiness levels are proposed: nominal, tolerance-based, measurement-based, and variability-aware. These levels clarify which engineering conclusions can be supported by different combinations of design data, manufacturing tolerances, measured component geometry, assembly information, end-of-line measurements, and population-level evidence. The preprint does not introduce a new simulation or experimental dataset. Quantitative findings are attributed to their original publications, which remain the primary sources. The new contribution consists of the cross-study synthesis, the simulation-readiness framework, the research portfolio map, the terminology mapping, the annotated publication appendix, and the machine-readable source–claim representation. The deposited research object includes the main preprint, an editable manuscript, a machine-readable source–claim map, BibTeX references, JATS 1.4 XML, Schema.org JSON-LD, DataCite-compatible metadata, RO-Crate metadata, CITATION.cff, and publication-quality figures.