My granny and the speakerphone

I live with my grandmother. Since it's just the two of us in a two-story house built for five, frequently we have to talk out loud:

-SONNIE?
-YEAH?
-COME RIGHT DOWN, DINNER'S READY!!
-WHAT??
-DINNER'S READY!!
-OH. THANK YOU!!

Yelling is fun, but after seven years, it kind of gets tiresome. So the other day, I decided to finally buy a couple of wireless speakerphones I saw at the hardware store.



They're great. You just plug them into a wall socket and they're up and running.

Despite this apparent ease of use, I can't tell you how hard it's been to try to teach her to use the dang things.
Even though it's a very straightforward procedure (press the button to talk, release to listen), she manages to get it wrong most of the time. She forgets to push the button, or she forgets to release it. Of course, it's endearing to see her try.