Two cups and a bit of string would probably do if they shouted

(dribble, Thu 28 Jan 2021, 22:09, archived)

noone can hear you shout in space
it's got to do with vibrations at close proximity. science is fun!
( Woodkovsky ☹️➝🚻➝🚽➝😣➝💩➝🧻➝😁, Thu 28 Jan 2021, 22:54, archived)

Yeah, so cups against the helmets, and string pulled tight
and shout to compensate for the lossy transmission
(dribble, Thu 28 Jan 2021, 23:05, archived)