As a foreigner born worker with a thick accent,
I will kindly say, we're more than aware of our accent, generally arn't proud of it, and are usually legit trying to speak better. In the country where I'm currently living, the locals like to say:
'I didn't understand you acoustically'
As a way to politely say they didn't understand what you said. It annoys me to no end as I know that isn't true. I and most people would simply prefer people not do the 'its not you, its me' and just simply say,
I'm sorry, I didn't quite understand your sentence, could you please repeat or rephrase?
This gives me the option to say it in another way that you may understand better, and it's honest. Apparently that specific word(s) I need to work on some more.
I generally, when having presentations, have points in the slides which say the subject I'm currently talking about. This may be something helpful to suggest to your college to add, to allow context to help you understand the current spoken subject.
The other thing I would suggest is, suggest getting a drink some time with the person, and just talk to them. You'll get used to their speaking style soon enough. ;)