When I phone my Mum she spends ages trying to find the mute button and sometimes gives up completely - so we have to talk with the telly on, very loudly, in the background. She only needs to change between 2-3 channels, switch the sound up or down or off completely. The controls are far too complicated and she can't really see the writing on them any more.
She does have the sound up far too high, and we're trying to persuade her to get hearing aids.
The idea of a fixed setting - sort of "cruise control" - would be great. I wonder how you can set that...