I got a Voice Modem at some point toward the end of the 90's. I played around with it and wrote an answering machine for it in bash. It announced a synthesized welcome message with date and time, and gave options for control of some elements of my home automation via DTMF (after authenticating). It was clunky, but it worked well.I came across it a few months ago while clearing out some old junk. I did not think twice about tossing it into the trash.