he could hear "voice of all" (I think that is what it called) like he could understand animals & hearing voice of sea kings & same power as Rogers which could use ancient letter (poneglyphl)
Well about he could hear a voice of all I don't think he could coz so far we only saw he only hear the voice of the animal just that.If he really can hear voice of all he will understand the poneglyph he found when they were in Alabasta (when he got separate and fell anderground).
But maybe I was wrong, we still don't know about it. coz this is the first time Luffy really react to the animal voice and It's a different matter with the sea king in fisherman island we can hear their voice because they have a conversation with Shirahoshi Hime.
don't for get the dog Chouchou he understood it when he, nami and zoro left the island after they beaten up buggy
This new chapter make just like.... Waow!!! And speechless...
So it's true Luffy can hear animal voice!! I remember the first time Oda sensei saw us is at fisherman island but he always drew when Luffy comunicate with animal around him but never put a words about what the animal say.
And this just makes me so excited!!!!