Microphone far away has potential, hmmm. Maybe the stream. Useless, but pleasant.
I thought about a CB radio, but it would need to be switchboarded, and then why not use it directly?
Also planning to install a cellular module with external antenna on a RPi for internet, could wire the cellular module's analog voice to the telephone line as part of that. But if I have internet, people can just message/email me if calls aren't going through.…