Raidergirl, I don't think you are mean, I just think you may not understand.
Let me put it this way.
How many times have you spoken to someone who has a very different accent to your own?
You can hear what they are saying, but you can't understand what they are saying.
As my Mum got older, she was always asking people to repeat what they were saying and yet she always heard what I was saying because she told me once, always look at me when you are speaking so I can see your lips, and don't mumble, no problem.
Now I am the same. If my grandchildren are running about while they are telling me something, I've no idea what they are saying, Try this with your family member. Talk face-to-face with them at a reasonable pitch and speak clearly. You don't need to talk too slow or loud or over-exaggerate your mouth movements. If they still can't hear or understand you, it's possible you could be right about them needing an aid.