From the age of 12, in case of discrepancy between the parents’ claims, courts are obliged to listen to minors.
This is valid in both, new procedures and those initiated to modify the guard and custody regime or to extend visits system.
Logically, minor’s voice is heard, but this does not imply that the court simply accepts his preferences.
All in all, my experience with minors declaring in court is bad. First, it creates themselves a loyalty conflict that they do not always know how to solve, among other reasons, because they do not have the necessary tools or enough experience to put everything in its place. That is the reason why sometimes their statements have nothing to do with what they have sid their parents in privacy. The result can be just the opposite of the desired one, so if it can be avoided, it is much better.
But as in all family matters, it is required to analyze every specific case: in this field, more than in any other, there are no topics or general recipes. Each family and each situation is unique and thus must be treated.