Radio!
Money Heist Season 3, Episode 8
RAJESH: (OVER RADIO)
Hey, buddy, how's it going up there?
The Big Bang Theory Season 6, Episode 2
(MIMICS RADIO STATIC)
The Big Bang Theory Season 6, Episode 2
It sounds like an encrypted RADIO system.
Money Heist Season 3, Episode 4
(DISTANT RADIO CHATTER)
Westworld Season 3, Episode 8