LOL! I remember those speakers perfectly well - they were there in my day too - but I just never heard them referred to like that.

Certainly, I remember that school-wide announcements were made. Also, the system could be used for communication between the office and an individual room as well. Especially ominous was being in the middle of class and suddenly the private announcement mode kicked in with, "Excuse me Mrs. _______, could you please send EMG down to the office!"

Down the hall I'd go, heart-in-throat wondering what I ever did wrong ....only to find out they just needed to verify that my address was correct in their records.

Here's a request to any school administrator who happens to be reading this - PLEASE have consideration and avoid scaring innocent young children unnecessarily! When they're being called down for innocent reasons, make that clear when making announcements like that!