Understanding the acoustic behaviour of wood is important both for explaining the biological functions of living trees and for developing renewable sound-absorbing materials. One effective way to achieve this understanding is through micromechanical modelling that links wood microstructure to its acoustic response. In this work, we present a three-dimensional microscale model of wood cells and first validate the elastic properties of the different cell wall layers. We then formulate the equation of motion, including stiffness and mass matrices, to construct the global dynamic stiffness matrix of a single wood cell. Wave propagation characteristics are investigated by solving eigenvalue problems using both direct and inverse wave finite element methods. We illustrate the dispersion relations of forward-propagating waves in a wood cell without pits, and we further analyse its forced response and displacement fields. Finally, we study wave diffusion in a wood cell containing a pit, focusing on reflection and transmission behaviour. Overall, the results demonstrate that the proposed framework is a promising tool for analysing wave propagation and diffusion in microscale wood structures.