Oh, BTW, let me share how announcements used to be during my childhood.
During the 90s refurbishment of the Portuguese railway network, stations were fitted with a DTMF receiver and decoder in order to issue announcements both locally and from remote access, through telephonic wiring. This DTMF system allowed for railway workers to communicate with each other, between them and the passengers, both locally and in a centralized control tower, and from passengers to the regulator as well.
This system eventually started being replaced around 2007 and has been almost completely extinct, being only used in places refurbished in the 90s where centralized control still hasn't reached.
I made the following video with the two usual codes used to terminate a connection with the station's announcement system, which were still audible to the passengers.
It has been replaced by this:
My current favourites are Japanese and are the following: Gota del Vient, JR-SH1-1, JR-SH2-3, JR-SH3-3 and JR-SH5-3