This is very true. Aside from accents, there are some dialects found in New Orleans that I guarantee many people would could hardly understand. A lot of New Orleanians may not speak much differently than people from other parts of the country, but we have a MUCH easier time understanding a lot of the dialects found here than someone else would. To be honest, I wouldn't rule out "new" New Orleans dialects/accents (not really new, but unique and different from what you would have found previously) being formed during our lifetime.