Looking for Suggestions for an Intercom

I'm looking for a better, more private solution to an intercom I have between the house and my barn. I have Ethernet run out there, and I currently use the "drop-in" feature on some Amazon echo devices. I'm looking to get away from the Amazon devices entirely (maybe implementing the pine speaker they announced?)

I don't have a lot of requirements, though VoIP would be preferred over a radio style, since it's a metal barn and blocks a lot of signals. I'm good with some self hosted solution, and ideally there's a dedicated device, as I don't want to use my phone or computer for it all the time. I'm probably missing some obvious solution, but figured I'd try to get some ideas together.

Thoughts?