Here we report a comprehensive study of hydride local environment and dynamics by employing 2 H solid-state NMR on three distinctly prepared BaTiO 3 x H y oxyhydrides with different hydride compositions. We support our experimental observations by using DFT calculations, which provide theoretical electric-field gradient tensor parameters sensitive to the local geometry. The combined results are able to conclusively differentiate the electronic structure between the polaron, single and double occupied bandstates in BaTiO 3 x H y and to provide new insights on the hydride diffusion mechanism. We anticipate that our approach will be very beneficial for the studying similar systems in the future.