High frequency pulsating electronic signal:
-
Morse code, welcome
-
Geiger counter
-
Morse code, SOS signal reception
-
Electronic signal
-
Radio Setup
-
Morse code, SOS signal transmission
-
Radio noise
-
Low-frequency rumble, high-frequency squeak
-
High frequency pulsating electronic signal
-
Radar, location alert
-
Low frequency electronic signal
-
High frequency squeak
★★★★★