what is an automated intercom system?

Question

How can this be designed?

Answer 1

I am guessing a bit what you mean by "automated"....
Most intercom systems require you to push a "Talk / Listen" button. An automated intercom could have a VOX (voice operated relay/switch) that "hears" that you are saying something, and automatically switches from "listen" to "talk".
That exists.
A higher definition would be that it does not react to any noise/talk, but needs a specific (and unusual) word to be activated (like in Star Trek: "Computer...!....").