A trick that can be used in a game with remote communication is to describe the action happening to one group of characters only by the sounds that another group of characters in a different location can hear. This can leave a lot to the imagination of the listeners. It can generate suspense or mystery, and might also potentially lead to incorrect conclusions.

It doesn't need to be radio either. You can separate an adventuring band in a dungeon with a sliding door and have ominous sounds drift through the now unopenable panel.

Transcript

Leia: Luke! We're heading to the Falcon! Get there as fast as you can!
Luke: {over radio} Not while there are camels still standing!
[SFX]: Whooom!
[SFX]: Sliiice!
[SFX]: Kabooom!
Luke: {over radio} Come on, you too! Oh, you want some of this?
[SFX]: Whooom!
[SFX]: Sliiice!
[SFX]: Kabooom!
Leia: Luke! Are you okay?
Luke: {over radio} I killed them. I killed them all.
R2-D2: Noooooo!!!