A 2D biomechanical model of the tongue is used to simulate movement sequences and speech signals in Vowel-to-Vowel transitions. The analysis is focused on how central commands and biomechanics can interact and influence the physical speech signals. In particular, it is shown how complex velocity profiles can be explained by the biomechanics, and how the low-pass filtering effect of the biomechanics can give an account of the vocalic reduction phenomenon that is observed during speech production.