Do you equip your "backup spotter" with a walkie-talkie?

I have a pair but have not been successful in getting t wife to push the button and speak she just holds the thing in her hand and yells. I had my sister do the same thing to me last summer.

I do not understand it. What is so hard about push the button and speak.

At night I have her stand near any obstacle and light up the ground next to it. Not sure why I still need to remind her not to stand between trailer and obstacle but that might have something to do with not remembering to push button to talk.