What I found better than calls, at least with my wife, is Zello - a walkie-talkie-over-IP-app. What seems to work for me is that the talk over it feels natural.

What I found better than calls, at least with my wife, is Zello - a walkie-talkie-over-IP-app. What seems to work for me is that the talk over it feels natural. Like you're shouting something from other room. It is synchronous and asynchronous at the same time. I respond when I can, there is no call hanging, the conversation is stretched in hours and it naturally fills gaps when we don't see each other.