The only instance that Pokemon have ever uttered their names a means of communicating is in the English dub of the anime. In all other media, Pokemon make grunts, growls, roars, etc. Sometimes those sounds happen to sound similar to their names, usually this happens with Pikachu. Depending on the media, certain individual Pokemon may have learned how to speak or can communicate through telepathy, but that's about as far as the exceptions go.
