Simple suggestion here gents. Make it so that people can send emotes through your radio that way you can send messages over comms such as:
John Doe coughs and spatters into his mic, only for it to cut to static.
or
John Doe breathes heavily into the mic, “Gentlemen, we have to get moving before the infected burst.”
or
John Doe says, “That sounds like a great idea, Captain” with the obvious scent of sarcasm on his breath.
YES, YES PLEASE.
Usually when I need to add an emote into comms, I just put it between brackets
Example: “(Cough cough) I’m sure this is a good idea…”, but having an actual way to input it I think would be better
It won’t be long after that for you to get:
You hear a faint purr in the background.
Wont also be long until you get people making shitting and farting noises over comms
We might need a new law for this 
I am pretty sure it would fall under hooligalism, funny unreasonable danger to marine’s life NJP time.