i couldn't make the words out even when I knew what they were. I know that in real life we're going to meet people that speak this fast but we're still at very early stages of learning and this isn't helpful. It almost makes me want to give up as I feel I will never be able to understand.
I have the feeling that Duolingo prefers gramatical structure over meaning. So Duolingo relies on similar structural forms in preference to answers that mean the same thing. So they have given the gramatically similar 'do you hear me', when I suspect that a better translation is 'can you hear me'. 'Can you hear me' is not functionally equivalent to 'do you hear me'. Although 'do you hear me' can be functionally equivalent to 'are you listening to me'. So IMO you did not deserve the negative point.
Do you hear me is almost certainly not a good translation. "Do you hear me?" is not a common thing to say in English. In English we use tend to use can for questions with verbs like see and hear. Can you see me? Can you hear me? Not do you hear me. This usually implies that the speaker is annoyed and it is more of an instruction. ie I want you to hear me.