I used to genuinely believe that I was deaf, so asked people to repeat what I hadn't heard. Repeating in the same wording doesn't necessarily help me understand though.
Now I know what the problem is, with people who know me well I ask them to speak slower, or rephrase what they have said in a different way.
At work I usually repeat back what I have been told in the form of a question to clarify whether I have understood. This works quite well as it appears as though I'm just being thorough, although it's difficult to break the habit of just pretending that I understood and then messing it all up, which is what I used to do before I knew about AS. If I am being given complex instructions I ask for it in writing. My colleagues don't know about my AS but they know I am a bit absent-minded and always write lists for everything, so it seems like a reasonable request to them. Unlike many employers, they don't expect everyone to be the same and have the same strengths and weaknesses, I like working here. 