Sometimes, the world you live in has its own verbal tics. Maybe the environment is a bit TOO empathic, or the animals a bit TOO skittish. But usually, it's the writer driving a Running Gag so far into the ground they pull it back out covered in fossils. Regardless of the whys and wherefores, the Hair-Trigger Sound Effect is a special class of Running Gag.
It isn't rare for certain words, phrases, or even actions to have a sting associated with its use. A smiling hero's teeth might glint, or a magical sword might be sharp even to the ears. But this sting doesn't always go away. Sometimes, it stays on WELL past the need. And that is where the Hair-Trigger Sound Effect comes into play. It isn't the fact that lightning flashes when a character mentions murder. It's the 18th time they do it. Bonus points if they realize they can control the weather, and occasionally use it to light up a room.
This trope is commonly used via a dramatic sting. It's not at all surprising for characters to notice it, or even notice when it DOESN'T happen. And if the fan base is really up on their game, you better believe they'll chime in when they hear the magic word.
Note that this is targeted primarily at the comedic use of this trope. There are times where an over-zealous sound editor abuses a Signature Sound Effect (though this does not prevent it from becoming accidentally hilarious). And words considered magic by nature of the plot are similarly not applicable. Just because thunder rumbles when you say the magic word for "storms" does not make it unusual.
Compare Left the Background Music On for when characters can hear the sting, or Terrible Ticking if only one poor bastard can hear it. The occasional Incessant Chorus may also get involved if they have a contract to complete. Otherwise, this will probably be the Signature Sound Effect from hell.
See also Overly Long Gag, which this trope is a common form of.
- Mickey, Donald, Goofy: The Three Musketeers: Every time Pete mentions the opera, the camera cuts to a poster of the opera and a few snippets of opera music play. Eventually, Pete admits that "that ditty's starting to grow on me."
- Sausage Party: Any mention of Firewater (*screech*) is met by the call of a distant eagle.
- The Curse of the Were-Rabbit: To kill the Were-Rabbit, you need... a bullet. (Dramatic Thunder)
- Young Frankenstein: The Trope Codifier. Horses are very uncomfortable with the idea of Frau Blücher *WHINNY*
- The Rocky Horror Picture Show: While not an in-universe example, there isn't a single well-seasoned veteran of the midnight showings that can let either Brad *ASSHOLE!* or Janet's *SLUT!* name go by without proper response.
- The Adventures of Rocky & Bullwinkle: There's a handsome-but-not-particularly-bright security guard. There's an Audible Gleam every time he smiles.
- Kill Bill: The Pai Mei training montages. Every single movement is accompanied by a cheesy whipping sound effect. Even the Bride's ponytail makes it making it literally a hair-triggered sound effect.
- The Hitchhiker's Guide to the Galaxy: The Astronomic Zoom from the beginning of the film. FIFTY-FIVE jump cuts. FIFTY-FIVE dramatic stings.
- Wet Hot American Summer: Any time a prop is thrown off screen is foleyed with the sound of a clay pot shattering.
- Mother: Played with in a subtle, unnerving way. Every scene in which the point of view is within Him's study, there is a soft, chime-like tone. There are three exceptions: first, when the Man and Woman break the crystal, the chime momentarily disappears; second, the chime does not sound when the mother is giving birth; and third, the same chime sounds as the exclamation point is drawn during the title card.
- The Gamers: Every time the Darknessnote is mentioned, another character will invariably question its name, and yet another character will affirm what the first character had said.
- GrailQuest: The Ghost Grunweazel (Do do do dooon!) in the book The Realm of Chaos is otherwise The Scottish Trope, as people avoid saying its name. Considering that every time the Ghost Grunweazel (Do do do dooon!) is mentioned, this sinister echo happens, it is understandable. The first time Pip hears it, he's quite freaked out.
- Pee-wee's Playhouse: While it changed Once per Episode, and was clearly invoked, you better believe that at some point, the whole house would go berserk when someone said the secret word. *AAAAAAAAAAAAAAAAAAAAAAAAAH!!!!!!!*
- Roseanne: Every time someone says the word "audit" during the tax episode, a dramatic fanfare plays. All the characters stop and look around for the source. After this happens one too many times, Roseanne screams, "I think we should get out of this house!"
- How I Met Your Mother: In the episode "Spoiler Alert!", the revelation of particular pet peeves, or spoilers, is always accompanied by the sound of shattering glass.
- Monty Python's Flying Circus: For the love of god, whatever you do, don't say anything about the fact that you're not expecting the Spanish Inquisition. *DRAMATIC STING* Goes even further, as it is accompanied by inquisitors jumping out of nowhere.
- Sesame Street: EVERY time the Count laughs, thunder follows.
- Borderlands 2: While there are a number of guns that can talk or have unusual effects, only the gun known as "The Bane" truly utilizes this trope. For every bullet fired from this (fully automatic) weapon, the player is greeted with the loudest, most irritating sound effect in the game. You actually get the thing after a long questline full of people considering it an Artifact of Doom and only figuring out why once you get it.
- Pimp Lando: Dow Jones's full name is "Dow Jones *villain music*"
- Britanick: In "The Dinner Party", every dark revelation is followed by a musical sting. At least until near the end, when the definition of "revelation" gets a bit out of control.
- The Venture Bros.: Any mention of the covert organization SPHINX *Sphinx!* will inevitably be echoed, if not by a member of SPHINX *Sphinx!*, then by a disembodied chorus.
- The Boondocks: During one episode, Huey discovers that his grandfather's date is a Mortal Kombat-style ultimate fighter who regularly takes part in a competition known as the Kumite *HIYA!*. Considering the Kumite *YAAA!* is a no-holds barred death match, anyone who claims to have fought in the Kumite *YOOHA!* is to be greatly feared.
- Muppet Babies: Gonzo played The Weirdo, and everytime his name was mentioned, Rowlf played a Musical Sting on the piano. Eventually, Gonzo got tired of it and asked Rowlf to knock it off.
- American Dad!: During "Deacon Stan, Jesus Man", saying Karl Rove's name *howl* elicits a wolf howl on every occasion. The characters can all hear it.
- Archer: Lampshaded and discussed when combined with Insistent Terminology during the Grand Prix episode regarding Benoit.
"BALLS! What, I can't NOT say it!"
- Animaniacs: One episode has the Warner siblings facing a terrifying troll, whose very mention is always accompanied by an organ sting.
- Earthworm Jim: Every mention of Bob the Killer Goldfish's home planet, La Planet de Agua is accompanied by a Latin guitar riff and a shout of "ARRIBA!"
- One episode of The Emperor's New School has the Condor Badge which has an intense sting follow after every mention. Kuzco takes notice and spends time saying Condor Badge and having the sting loop over itself.
- Freakazoid!: Bleeding over heavily into real life, the villain Candle Jack would kidnap people who mentioned him. In this instance, the silence itself would be the accompanying effe—
- OK K.O.! Let's Be Heroes: Whenever K.O.'s friend Dendy makes her first appearance in an episode, she is often accompanied by a stock clip of a crowd of children cheering.
- Phineas and Ferb: In "Bowl-R-Rama Drama", there's a trumpet fanfare every time Baljeet mentions "the World's Most Pointless Book of World Records". It's revealed Buford is actually playing the fanfare on a horn.
Baljeet: Is that absolutely necessary?
Buford: Why? Does it bug ya?
Baljeet: Well, yes, a little.
Buford: Then yeah, it's necessary.
- Scooby-Doo and Guess Who?: Happens as a Running Gag in "The Feast of Dr. Frankenfooder." Whenever guest star Alton Brown or another character says "Frankenfooder", Dramatic Thunder crashes and a wolf howls. At one point in the episode, Alton says it when near an open window, and a wolf suddenly appears in said window making the howling.
- As per the rules of The Game, which you've now just lost, you are required to announce the fact that you lost The Game, making this an enforced trope.