The Gemara has a a Shaila if someone could be maifer before he hears. The Gemara wants to bring a proof that before the Nesuin, both the husband and the father Maifer all Nedarim until now, since they can't do it do it anymore for these Nedarim after the Nesuin. The Gemare rejects it that the father starts up with her so that she would reveal to him all the Nedarim she made (to show him how angry she is.)
The Ran says there are those that require the same from the husband. ALthough he may still be Maifer after the Nesuin, but not for Nedarim that she made before the Nesuin. So he needs to know about, and be Maifer before the nesuin. However, there are those that versions don't require that by the husband. He may just simply say I'm being Maifer your Neder to take effect after I hear about it. Although after the Nesuin he cannot be Maifer by himself Nedarim she made after Airusin. However, since he can Maifer at that time, and the father already Maifer before Nesuin, we cna combine the two hafaros.