TPC
An artifact from when I worked as a long distance telephone operator, back when you heard the coins drop into the box (a higher sound for a dime, a quarter sounded "deeper" than a nickle), clips for the cords, and mechanical timers, pencils for bubbling in the number of minutes, headsets, cords, uncomfortable chairs, and this ....
Because this subsidiary also served some small portion of the local area, every once in a very great while I heard a voice I recognized.