I'm glad you have so much ingenuity!
I have a vision of you trying out different voices with a text-voice machine.
You could give everyone a shock by selecting 'Steven Hawkings', or 'Darth Vader'.
Actually, have you tried to get an OT to give you a text to voice machine?
They were giving them out on my MS ward when my legs first stopped working (don't worry, I don't want the old legs back - I would have to go back to work for a start). It was 15 years ago, so I expect that they have come a long way since then.
And blind people use text-voice the whole time - then you could have 2 way phone calls.
Does that help?
Your GP should be able to connect you with OT or a charity website like sense might be worth a look.
Sorry if you have already explored this route and found nothing to match what you need.
My other thought is all those people that I would love an excuse NOT to talk to like those annoying calls about ppi and trying to say that they can help you with your recent accident/computer crash etc etc. Alas I have to deal with them and you don't.
And all those times I say really embarrassing things - I heard about a chef who had an accident and was having his fingers sewn back 'we are just waiting to see now how much sensation he will get back'. I said, really, 'well, fingers crossed'.
With my 'yes/no' relative I realised that he still had all his body langugae and sense of humour. I do a lot od work with ASD and we see research that says non-verbal language is 60-80% of human communication. It was so clear with him, and quite reassuring - he could still make it clear that he loved to hear news of/from the kids, and all the things that he appreciated. I suppose it was just so clear that he still really loved and cared for everyone, and the rest somehow seemed much less important.
Take care