Suddenly Shouting

Two characters are carrying on a conversation. John Doe says something. Richard Roe responds in his regular voice, but then SUDDENLY HE'S SHOUTING!

Typically happens for one of three reasons:
 * Anger: Something John said just really infuriates Richard, or perhaps simply made an already bad mood worse. Often this is preceded by other visual cues of anger, such as a twitching eye, giving the impression that despite his feelings Richard is still trying to maintain some sense of composure before finally giving in and letting loose with an impassioned tirade.
 * Surprise / Fear: Richard is carrying on as normal, when suddenly a cold, dead hand settles on his shoulder, or someone sets off an explosive in his presence, or something else happens that he just didn't or couldn't expect. Often accompanied by an upward shift in pitch.
 * Drama: Richard is naturally a Large Ham and wants you to know that what he is revealing is quite important, no matter how mundane it may actually be.

Compare Careful with That Axe and Last-Note Nightmare, which apply a similar sort of logic to music. Sometimes overlaps with This Is Sparta or Ha Ha Ha No.

Advertising
""[...] ads where the announcer SHOUTS AT YOU AS THOUGH YOU ARE AN IDIOT and then reads, in very muted tones, what sounds like the entire US tax code.""
 * Lampshaded in a Dave Barry column on ads he and the rest of the world hates:

Anime and Manga
"Kyon: Okay, how is this happening right now? If your mouth gets any closer to her, someone standing off camera is gonna step into frame and KICK YOUR ASS, DAMMIT!"
 * In the Haruhi Suzumiya episode "The Adventures of Mikuru Asahina", when Itsuki attempts to kiss a drunk Mikuru:

Comics
"Jon: Be careful there, Garfield. Hanging on the drapes can be very painful. 'CAUSE I'M GONNA BREAK YOUR LEGS IF YOU DON'T GET OFF THEM THIS INSTANT!"
 * In an early Garfield strip:

"Jon: Some dirty, rotten, low-down, slimy, filthy, disgusting, gluttonous, hog STOLE MY SUPPER!"
 * He also does it again in this strip:

Film - Western Animation

 * Toy Story 3: "He was putting you IN THE ATTIC!"
 * "He's not a space ranGER!"
 * The Iron Giant: "What you currently have IN YOUR MOUTH IS ART!"

Film - Live Action
"Garry: I know you gentlemen have been through a lot, but when you find the time, I'd rather not spend the rest of this winter TIED TO THIS FUCKING COUCH!"
 * The Thing (1982). Garry (the station commander) was tied down in case he was one of the Things. He has just been proved to be human and not a Thing, but he's still annoyed.

"Austin Powers: WHO ARE THESE PEOPLE? Basil Exposition: The shouting is a temporary side effect of the unfreezing. Austin Powers: Yes... I'm having difficulty controlling THE VOLUME OF MY VOICE."
 * In the first Austin Powers film, when Powers gets thawed out:

""Again, something that could have been brought to my attention YESTERDAY!""
 * The Wedding Singer:

Live Action TV
"The Doctor: If there's one thing I do, it's talk, so if anyone's going to be silent, IT'S YOU!"
 * From Doctor Who, New Series 1 finale (paraphrased):

"Kenneth Rhys-Evans: That reminds me of a story that's in no way related. I was working with John Gielgud in a production of Troilus and Cressida, when I discovered I had no control OVER THE VOLUME OF MY VOICE!"
 * Mike Myers used this in the same manner as the Austin Powers example when he was on Saturday Night Live.

"Frasier: This morning you said you two met on a double date. Roz: Oh that's right, we did meet on a double date! Frasier: THIS MORNING YOU SAID NOTHING!!!"
 * Crowley from Supernatural does this a lot.
 * On Frasier, Frasier Crane is the master of this trope:

"Mal: "While this is touching, Yosaffbridge, I really- DROP IT, NOW!""
 * Firefly Mal has a particularly good unexpected one during a stand off with his "wife" in the episode "Trash".

"Host: Mr. Dove, I believe you're interested in shouting. Dove: (full volume) YES, I'M INTERESTED IN SHOUTING, ALL RIGHT. BY JOVE, YOU'VE CERTAINLY HIT THE NAIL ON THE HEAD WITH THAT PARTICULAR OBSERVATION OF YOURS THEN. Host: And what does your wife think? Mrs. Dove: (full volume) I AGREE WITH HIM! Dove: SHUT UP!"
 * "Scaring the little gIRL?! LADY!!"
 * Monty Python's Flying Circus had a panel show, "Interesting People" featuring Ken Dove, a man who likes shouting.

Manga and Anime
"Colonel Mustang: When I'm Führer, there will be changes. That day, all female officers will be required to wear... TINY MINISKIRTS!"
 * In Dragon Ball, Bulma uses type A for snark value when complaining about how recklessly endangering her companions are.
 * Fullmetal Alchemist:

Video Games
": Kuru ga ii...Yuriusu...BERUMONDOOOOOO!"
 * Castlevania Dawn of Sorrow: The final boss of the bonus mode,, does this when you fight him with the titular character.

"Look! Rhinos, RHINOS! Our enemies hide in METAL BOXES! The cowards, the FOOLS! We... should take away, their metal boxes."
 * This legendary line from Dawn of War Soulstorm:

Web Comics

 * This is trademark speech quirk in Homestuck. The other characters even complain about his volume fluctuations.
 * To be really evil, pretend you're telling a secret as Abel does here in DMFA.

Web Original

 * That Guy With The Glasses does this when something really pisses him off.

Western Animation
"King Voracious: That baby...Daddy was telling SUCH A NICE STORY!"
 * The Foxbusters: