Morse code, SOS signal reception:
-
Brown noise
-
Location alert, Radar
-
High frequency signal
-
Police radio
-
Radio Setup
-
Electronic signal, energy buildup
-
Low frequency electronic signal
-
High-frequency squeak, Low-frequency rumble
-
Geiger counter
-
Horrifying throbbing low-frequency rumble
-
Interference Broadcasting
-
Morse code, SOS signal reception
★★★★★