I don’t remember the medical term, but I once met someone who had a bizarre accent- a little like he was switching back and forth between British/American Midwest accent. He explained he had some sort of hearing/processing issue, and he actually has to vary his accent a little in order to consistently hear what he is saying.

My aunt does something similar in regards to mimicking accents- it’s totally subconscious, and it’s led to a few awkward situations (people thinking she’s making fun of their accent). She can usually control it if she’s concentrates, though.