I've noticed on stage that he often has an accent on stage--and it sounds more like a Southern accent than a Jersey accent. If you've ever heard him speaking from 1984 interviews or even during shows, he had a really strong Jersey accent. But it definitely changed over the years. It's really quite common for singers and actors to take speech lessons to get rid of their accents. It's better for marketing to be able to be more easily understood--don't speak too fast; don't speak too slow; watch your intonation...