The Chaoshan (潮汕) region has its own language, Teochew (or Chiuchow) – which isn’t mutually intelligible with Mandarin or Cantonese, actually I find it closer to Minnan (my dialect) spoken in southern part of Fujian Province with accent variation of course.
If you speak Teochew, you can get by easily in Chaozhou, Jieyang and Shantou this should not pose too much of a challenge. (Was there because I like Teochew cooking very much.)
Spectacular 800-year old Guangji Bridge (aka Xiangzi Bridge) was built, as a floating bridge, during the Song Dynasty across the Han River in Chaozhou, Guangdong province. A pontoon bridge that can open and close in the mid section, supported by eighteen floating boats – flexible construction, a bridge to unite people like languages do.
Regionally Chaoshan is a part of Guangdong province and many do understand Cantonese although they may not get to speak it. I’ve a few bona fide Teochew friends who converse with me in Cantonese, and of course Mandarin – after all, it is the standard for education countrywide.
My Malaysian Teochew buddies in Kuala Lumpur and I chat in Cantonese and English, not Teochew, even though I am versed. I think language is often a matter of where you’re located, what are the main languages/dialects spoken locally – it’s nice to be able to communicate using several languages.