when reinstalling oblivion it changes some folders in the data folder to bsa files(meshes, textures, voice) the textures & meshes work fine but the voice isn't responding like the other 2 it makes the game crash whenever i try to engage in a conversation the game crashes. how do i get the bsa files back to the original folders?

The .bsa files have always been there. It's how Bethesda packaged their files. You might have had a problem when reinstalling.

try doing an archive invalidation (you can use OBMM to this)
BSA have similar structure as the data folder compacted and the engine will try the files most recent, being in BSA or folders