The article presents a method of post- synchronization which is the match, by means of formant-to-area mapping, of an area function model to a measured area function. The objective of post- synchronization is to compute a model which is as near as possible to a measured area function and whose eigenfrequencies are identical to the corresponding measured formant frequencies. Different types of acoustic models and constraints are examined. Results show that the best map is obtained in the case of a lossless acoustic model, corrected for lip radiation and wall vibration losses, and the minimization of the Euclidean distance between geometrically fitted and formant-to-area mapped area function models. The differences between measured and mapped area functions are gauged by means of the dynamic length warping distance.