I think that's the nature of learning a new language. I constantly have that problem of not recognizing words as they are spoken, even when I know all the words. Keep practicing... :-) But, yes, the text-to-speech can also be poor or even a bit wrong at times.
I don't believe that "...what you have been doing there" is a correct translation. Present perfect continuous denotes an action that is still going on in the present, and that doesn't match with the Polish past tense. Or can the imperfective aspect imply such a meaning?