In college, I had a Japanese linear algebra teacher who was not a native English speaker. The subject matter was new and difficult, so with new terminology to learn, it was sometimes to difficult for my classmates and me to understand certain words through his accent, mainly because they were new words that we had not heard before, or heard in proper context. Also, just like most of my college professors, he didn't have the neatest handwriting on the whiteboard.
So the one I will always remember is a "Arfa". It was just a squiggally unfamiliar symbol on a whiteboard, some new mathematical entity called Arfa, no big deal. Eventually, we came to learn that this was the greek letter "alpha," but there were a few classes where several members of the class were referring to it as Arfa because that's what we understood that symbol to be called. Eventually, someone figured out that it was the letter "alpha" and we called it that from then on.
So, is there a word or term for this type of mispronunciation? (Not the professor's, but the students' mispronunciation)