Say what now? DOES NOT COMPUTE. haha
Superman comes with his own voice file, like all characters.
Check that in the program files where you installed MUA, inside the folders:
has the files sprmn_m.zsm and sprmn_v.zss.
If not, reinstall the mod.
If they are and you still aren't getting voices, start a new game.
If that doesn't help, try a therapist.