You have a good ear for accents and dialects and can reproduce them accurately. You gain Advantage on Entertain (Acting, Comedy) and Perform (Clowning) Tests. Additionally, you may replicate any accent you are exposed to for at least a day, which may help with dealing with locals in an area at the GM’s discretion.
If you are familiar with an accent, you know if another is attempting to fake it or hide it unless they also have Mimic.
Core Book, Page 122