The special sound effect that makes any conversation over Comm Links sound immediately military. A transmission usually starts off with a recognizable click, then follows the actual text, along with audible white noise in the background, then ends with another click. Both sides cannot speak at the same time (also known as half-duplex operation.)
Goes very well with Danger Deadpan voice, Military Alphabet, Reporting Names, Radio Voice, and Attack Pattern Alpha. However, it doesn't always have to indicate military: Voice with an Internet Connection often sports this sound effect, too, simply for the Rule of Cool.
Amping up the static is a typical way of having a message get Lost in Transmission.
This technique is actually a pretty realistic portrayal of modern Real Life voice transmission over frequency modulated radio systems, which for the most part are used by the military, police and emergency forces. The distortion is the reason the Military Alphabet was invented. The click at the start and end is the empty carrier wave while the person is not talking but has the transmit button depressed.
- Stormtrooper helmets in Star Wars do this, as well as the ship-to-ship communications of X-wings and other Rebel starfighters.
- Parodied in The Young Ones episode "Cash". The police recruiting sergeant (who bears a strange resemblance to Mussolini) tells Neil the only qualification he needs to join the force is the ability to imitate radio static when using his walkie-talkie.
- Spoofed when The Goodies are launched into space. While communicating with Graham at Mission Control, they keep saying "Beep!" at the end of every transmission.
- Quindar tones are also used in the Blake's 7 episode "Killer". Unfortunately this is a case of Technology Marches On.
- Sheldon in The Big Bang Theory insists on adding this verbally at the end of each sentence during a Skype-type videochat via laptop with Howard while the latter is in space.
- Used to prefigure any flashback or Gilligan Cut in Brooklyn Nine-Nine, evoking police radio static.
- This is part of what makes Counter-Strike predefined radio messages so awesome.
- All Terran units in StarCraft have this in their responses to orders.
- Ditto all units in World in Conflict.
- Most of the dialogue in Call of Duty 4 and later.
- Merc in Mirror's Edge.
- The Replica in F.E.A.R., who all speak over radio wiith electronically filtered voices. Project Origin actually shows why they only speak with filtered voices, as it turns out their "natural" voices sound like harsh, guttural, inhuman growling.
- Friendly NPCs also get this if you're beyond a certain distance from them while they're saying something.
- Most of the dialogue in the Ace Combat games, since it primarily takes place via radio communication between planes.
- All unit responses in Homeworld and its sequel, Homeworld 2.
- The Star Fox series uses this for the same reason as the Ace Combat example above.
- XCOM: Enemy Unknown: In the expansion Enemy Within this is the sound made during the EXALT (a clandestine paramilitary group opposing XCOM) turn in covert operations. It comes in contrast with the other-worldy alien gibberish that plays during 'ALIEN ACTIVITY'.
- In the Lilo & Stitch: The Series episode "Clip", when the duo try to sneak into Mertle's house, Lilo does the radio click thing with Stitch as though they're talking on walkie talkies (they weren't actually using them, just pretending they were).
- In an episode of Bonkers, the titular character refused to stop making this noise, even when he wasn't on the radio.
- In Static Shock Virgil and Richie use walkie-talkies they call shockvoxes constantly, from the moment Richie builds them. In the episode where Virgil's sister, Sharron, suspects he's Static, Richie obviously can't hear that Virgil has left and that Sharron is in the room because he's speaking into the shockvox. Sharron hearing Richie call Virgil Static sets off the rest of the episode.
- Parodied in Sponge Bob Squarepants where SpongeBob and Patrick pretend to be astronauts talking through radio, eventually just start alternating static noise.
- Starship Troopers: Invasion: Every time the Alessia sends an audio message to the troopers, it is preceeded by a digital tone. None of the Troopers' radios do this, nor do any video messages sent by anyone.
- Inverted on general-use FM walkie-talkies (FRS/GMRS, PMR 446, etc), where most of them by default include call tones ("Hey you!") and "roger beeps" (indicating end of transmission), but due to the way the squelch functions on such walkie-talkies work, the user never hears the static unless the walkie-talkie is put in monitor mode.
- Many professional and ham radios have an adjustable squelch control to keep constant static from being annoying. Weak signals may not be able to break through the squelch, so the Lost in Transmission trope can (and often does) occur.