
It sounds like an encrypted RADIO system.
Money Heist Season 3, Episode 4

(MIMICS RADIO STATIC)
The Big Bang Theory Season 6, Episode 2

RAJESH: (OVER RADIO)
Hey, buddy, how's it going up there?
The Big Bang Theory Season 6, Episode 2

Give me your RADIO.
Money Heist Season 3, Episode 2

( screaming, gunfire
over RADIO )
Westworld Season 2, Episode 7