Now I really don't know if this works, but I have heard that simply pressing your helmets together (Ooh Matron!) and shouting can let you hear a surprising amount.
As I say I have not tried it but it's got to be worth a go, especially if it isn't too good, as in
"Can we look at that shoe shop?"
"Sorry love I cant quite hear you"
"That looks like a nice pub"
"So it does" Blast given the game away!
