Kendo Rage - Makeruna! Makendou (Help)

[xCRISZx]

I'm translating the American version of Kendo Rage for SNES into Spanish, but I'm using the Japanese dialogues. I have restored almost all the graphics, but I still need to restore the most important thing, the character voices that were muted. I think these voices are still in the game, but they need to be turned off. My knowledge in this is very low, I have asked for help, but I have not been successful, I hope that here you can help me in some way.

This is a good game, only in America they made the mistake of changing the story, this story is meaningless and does not match the images shown, for that reason I am doing a translation using the Japanese version.