Stroke and phone calls

Not sure quite why this is, but when friends phone why is it that several of them decide they have to speak "down" to me as if I was stupid? This happens time and time again and is very annoying. As far as I can tell my intellect is fully intact and I am very far from stupid! Maybe it is because my voice still sounds odd (a bit) and I have to speak more slowly to be understood? It must be even more of an issue for others with physical impairments much worse than mine.

If you are a friend phoning me please treat me absolutely normally. I am NOT an idiot and do NOT want to be treated as if I am.