I believe you’re thinking of France’s minitel (wikipedia) . I never used or saw it myself. Living in a neighboring country, i did see quite some adds mentioning it on their tv stations. Trente-six-quinze-minitel! Club Dorothée FTW! :)

Best match I could find: https://en.m.wikipedia.org/wiki/Public_address_system

We called it the PA. Back in the day when I was involved in organising and setting up parties and small concerts. (each about once a year). Not very accurate (looked it up just now) , but you might hear it referred to as such.

We’ve even been doing that for thousands of years!