I want to play Call of the Wild with a friend and be able to talk to him while we're hunting. How do I do this?
There are quite a few options available to you. I would say the most popular solution would be to make a discord server for you and your friends: https://discordapp.com/
I also am pretty fond of TeamSpeak, but you have to pay for it. A workaround I have found for this is to visit https://teamspeak-servers.org/ and look for servers with no people on them.
Steam also has a voice-over-IP function, instructions on how to use it from Steam:
To begin a voice chat with somebody, open a regular chat with them on Steam and click on the arrow button located at the top right of the window. From the drop down menu select Start voice chat. The person on the other end will be alerted by a ringing sound and a Steam notification.