Silent Slice Of The Swordsman
2 parts Complete MatureEveryone thought Zoro is a brute who can't speak well and ignores them, Sanji especially thinks that. What happens when they learn that might not be the case? That all of Zoro's actions have a reason behind them.
This is in the same world as the AcexMarco fanfic I read, it's one of my favorites. It's on AO3, Deaf, by Skyline_e