Helium Speech

"A mouse in the wainscotting! Well squeaked, mouse!"

- The Doctor, Doctor Who, The Robots of Death

Because helium is lighter than air, when you inhale it and try to talk it causes the vocal cords to vibrate at a higher frequency, resulting in reedy, duck-like voices which can be used to great comic effect. This can be tried in real life, although it should be noted that helium displaces oxygen in your lungs, so breathing it too long can be harmful.

Gasses that are heavier than air, such as sulfur hexafluoride and xenon, have the opposite effect, resulting in a temporarily evil- or gruff-sounding voice, but this rarely appears in fiction probably because the gas is less widely known. They're also a lot more dangerous; for obvious reasons, it's easier for a heavier-than-air gas to build up in your lungs than a lighter-than-air gas. Unless you're standing on your head.

Because it is easy, plausible in many settings, and can be very funny, helium voice often shows up in fiction.

It should be noted that contrary to popular belief, helium actually changes the timbre (as in the quality) of one's voice, not the pitch. Regardless, those who favor the easy and cheap way of getting things done or just didn't do the research still go for artificially pitch-shifting the characters' voice in spite of this tidbit.

Anime and Manga

 * An episode of Pokémon involved Team Rocket using the rather smart plan to disrupt the voices of an Officer Jenny and the other Trainers using helium, so their Pokémon wouldn't recognize their commands. Then they used voice changers to imitate the Trainers' usual voices.
 * It fails because the Pokémon are able to tell who their real Trainers are in the end.
 * The Cowboy Bebop episode "Waltz For Venus" features an expedition to the titular planet, whose atmosphere consists largely of helium when the series takes place. Naturally, it has the expected effect on the characters' voices.
 * In episode three of Wandaba Style, The Professor's latest experiment involves the girls of MixJuice and Satellite Girl Kiku#8 taking a blimp filled with experimental helium into the stratosphere. On the way up, they end up losing most of their air supply, and Kiku replaces it with "extra" air. Unbeknownst to any of them, the air was actually some of the helium, which they find out when they're giving a concert.

Commercials

 * Used in this his Twix commercial.

Film
"Note to self: Forget about having kids."
 * Police Academy 4 has characters switching helium and oxygen bottles to play the trick on Harris.
 * Which would actually be rather dangerous since inhaling helium for too long can be deadly. But then that's really not important, now is it?
 * To be fair, it was for a demonstration of an EMT oxygen mask, so actual harm would have been difficult.
 * My Best Friend's Wedding
 * Robin Williams has this in Club Paradise when he went diving.
 * The Martians in Mars Attacks!!.
 * In Hot Shots! Part Deux! the President of the United States, played by Lloyd Bridges questions while diving why he brought helium instead of air - with the voice shift at an appropriate point of the Inner Monologue.
 * Also, in the first movie, a character injures his groin on the tail of a plane, and squeaks "I'm okay."
 * Used to get the voices of the Toy Story Martians, rather than artificially speeding up the voices.
 * Turned on its head in the first Alvinandthe Chipmunks movie: there's a scene where Alvin inhales helium, but since his voice is already high-pitched, it becomes low-pitched instead.
 * A definitive You Fail Physics Forever moment, even if it is funny.
 * In Flubber, Robin Williams' character's flubber experiment causes a helium gas tank to leak open and you know what happens after that.
 * Sneakers: Carl does this during a party at the team's HQ, much to the amusement of the other hackers.
 * Broadway Danny Rose: Woody Allen with a helium voice. Heh heh.
 * Max Keeble's Big Move had Robe trying to pass the time waiting for Max to arrive for his going away party by blowing up balloons to get the desired effect. As soon as he does get it, he shouts "Yee-haw!" in a very high-pitched voice, and sounds this way for the remainder of the scene.
 * In Dirty Work, Mitch sounds like this, after his father crushes his balls.


 * "When I killed you brother, I talked... JUST...LIKE...THIIIIIIIS"

Literature
"Where fields once grew, a road runs through, and buildings hide the sun, Where grass of green could once be seen, are only gray and brown. My childhood home, while I did roam, became a place of sadness. Now I return, my heart does yearn for times of light and gladness."
 * In the latest Star Wars Expanded Universe novel (Fate of the Jedi: Outcast), Luke Skywalker's teenage son Ben removes his oxygen mask on a planet with a lot of helium in the atmosphere. He then goes on to sing a song to the annoyance of his father.
 * Here's the song:


 * A very sad song. Until you imagine it in a helium voice.
 * The Eye of Argon is often read aloud this way.
 * The title character of Stepsister From Planet Weird is from a shapeshifting alien race that lives off helium. When her Earthling stepsister walks in on her sucking the helium from a party balloon as a snack, the alien tries to explain herself and is surprised that her human form suddenly has a high, squeaky voice.

Live Action TV
"Randy: (inhales balloon air) (in helium speech) We represent the lollipop guild, the lollipop guild, the lollipop-- Darnell: Randy, those aren't helium balloons. Randy: (Normal voice) Aw, too bad."
 * In Farscape, Rygel will, if nervous or angry, fart helium. Anyone in close proximity to him will start speaking in a high-pitched voice.
 * MythBusters not only does this during experiments where helium is involved, but they've also used Sulfur Hexafluoride, a gas six times denser than air to get the opposite effect, with a "Don't try this at home!" warning from Adam right before he starts inhaling the stuff. Watch it here.
 * And while it did make his voice almost demonic in how deep it sounded, it would later be revealed that the Sulfur Hexafluoride displaces the gas in the lungs required to - you know, breathe - and that a potential side effect of breathing it in could very well be death.
 * Parodied in Will and Grace, a character with a high pitched voice doesn't sound any different.
 * One episode of Friends has Chandler inhaling helium and singing "I Will Survive".
 * Doctor Who uses this for a non-comedic purpose in The Robots of Death. After the villain controlling the robots orders them to kill the humans (except himself), the Doctor gets Leela to open a cylinder of helium so that robots won't recognise the villain's voice and kill him. The Doctor is unaffected by the helium though, due to his Bizarre Alien Biology.
 * On Genius, Dave Gorman and guest Neil Innes couldn't resist giving this a try when someone suggested Helium-filled bubble wrap.
 * The Day Today uses the trope to particularly hilarious effect in a report on Sinn Fein.
 * Art Imitates Life - The Day Today mastermind Chris Morris, as a junior in radio, released helium into The BBC's air vents just as the news was about to be broadcast.
 * Once on The Price Is Right, announcer Rich Fields inhaled helium before reading the prize copy as part of a Showcase skit. He then did it again for his signoff.
 * There was also an episode of Wheel of Fortune where, on a set decorated with balloons, neither Pat Sajak nor Vanna White could resist.
 * The most recent season finale of Eureka, after the teaser, involved Jack, Zane, Fargo, and Tess speaking like this as a result of leaking liquid helium coolant.
 * In The Big Bang Theory episode "The Vengeance Formulation", when Sheldon appears on the National Public Radio talk show Science Friday, his enemy, Barry Kripke, fills his office with helium.
 * In the episode "The Launch Acceleration", Leonard shows Penny how the sulfur hexafluoride he uses in his experiments causes deep voices.
 * One death in 1000 Ways to Die (#226, to be exact) involved a teenage couple breaking into a large helium-filled basketball due to this trope. By the time they realized they couldn't breathe, they were in no state to find the seam again.
 * Presumably based on this 2006 Darwin Awards story.
 * Wayne Brady of Whose Line Is It Anyway? was known for pulling this off without actual helium.
 * The Eureka episode "What Goes Around Comes Around" has a particle accelerator that's cooled by liquid helium. Naturally the cooling line breaks and everyone becomes squeaky for about half a scene until they can shut the line off.
 * Top Gear once tested how well the roofs of old convertibles had held up by putting the presenter in their vehicle with an open tank of helium. James and Jeremy's roofs were in good condition and held in the helium, resulting in them getting squeaky voices. Richard's heavily-modded convertible allowed the helium to leak and didn't change his voice at all, much to his disappointment.
 * In My Name Is Earl:


 * On Cheers, Norm and Cliff sing "Lollipop" this way at Rebecca's bridal shower until Frasier stops them.
 * On Ellen, Ellen DeGeneres decided to put deep-voiced American Idol winner Scotty McCreery to the test. The results, or lack thereof, were amusing.
 * In one episode of Late Night with David Letterman where the theme of the night was audience voting, the audience voted to have Dave's and his guest's voices electronically modified to sound as if they had inhaled helium. Dave's guest (Jane Pauley) refused to talk after that.

Music

 * Ween's Push Th' Little Daisies is popularly believed to invoke this trope. Also overlaps with Lyrical Dissonance.

Newspaper Comics

 * In one FoxTrot strip, Jason imagines himself floating to the ceiling after inhaling helium, only to express his disappointment (in curly letters) that it only makes his voice funny.
 * On The Far Side, some big dogs take turns inhaling helium balloons and barking like small dogs.

Other

 * There's a Mad Magazine gag where two men come across a vending machine labeled "A hit of helium - $1.00." The first man takes a hit and then speaks in a squeaky voice (represented by a lot of whitespace in his speech balloon). The second man, having only a quarter, puts his money in a machine labeled "Helium substitute," and a boot comes out to kick him in the 'nads, having a similar effect on his voice.
 * In the Robin Williams stand up routine Weapons of Self Destruction, he states that this is the reason why we need to invent cars that run on helium. Because there would be nothing funnier than two angry guys getting out of the car after a wreck and having them going "I'm gonna kick your ass... Crap, I think one of us has a gas leak."

Truth in Television

 * Truth in Television of course.
 * One professional use: Tony Shaloub in the Men in Black movies, as the head of his character is blown and grows back.
 * This trope often shows up in works set deep underwater, like the book Sphere (not the godawful movie). This is Truth in Television to some extent; the nitrogen in normal air becomes toxic at very high pressure, so deep divers breathe a gas mixture which has had some or all of the nitrogen replaced with helium.
 * However, films in such settings often purposely ignore the effect when it should be present. Having live actors breathe helium for every line would be distracting to the audience, not to mention being somewhat dangerous and ridiculously expensive.

Video Games
"I think we may have (shift) gas leak."
 * Rayman uses this practically in the opening of Rayman Raving Rabbids 2. You'll see.
 * Guybrush in Monkey Island 2: LeChuck's Revenge, shown through giving his dialogue lines a tiny font (the remake of the game has voice acting, so you get to hear it). Also used in The Curse of Monkey Island, which had voice acting as well.
 * Helium is an important element of several puzzles in one of the Sam and Max games, since it lets Sam sing high notes. Badly.
 * Used in the prologue of Ever 17. Before visitors can enter the underwater theme park of LeMU, they must go through a compression chamber and adjust to the change in air pressure via helium. Earphones are given to each visitor to make everyone's voices sound normal, but when Takeshi removes them and talks to an already high-pitched Coco...
 * The Science Vessel in StarCraft has this as one of their Stop Poking Me sounds:

"Really nice helium, heheheh."
 * In Conker's Bad Fur Day, if you use the first Context Sensitive Button for a second time after Conker's hangover is healed, he'll pull out a helium canister, which Birdy will snatch and huff (as if he was drinking a beer, actually):


 * In The Simpsons Game one of Homer's powers is inflating himself in which he'll say random dialogue in helium speech. "I'm slightly lighter then air".

Web Animation

 * Homestar Runner played with this trope a bit in the appropriately named SBEmail.
 * Later, we find that sucking up bandwidth has this effect on Strong Mad. Don't ask.

Western Animation
"Stewie: I'm a female! I have a high voice! I have reproductive organs inside of me, and I buy groceries!"
 * Happened unintentionally to Earthworm Jim in the animated series, with Peter Puppy being unable to stop laughing.
 * Used in Clerks the Animated Series; Silent Bob inhales helium and stands in silence for several seconds. Jay tells him in exasperation, "It's only funny if you talk, stupid."
 * In the third installment of Ice Age "deadly gas" turns out to be helium which, as mentioned before, can become deadly after extended periods. The characters' discovery leads to an Alvin and The Chipmunks impersonation and Hilarity Ensues. It is later explained that the deaths were because the victims died laughing.
 * Well, you can literally die laughing. Inhaling too much helium can displace the oxygen, suffocating you. Also, one elderly man died while watching Monty Python's Flying Circus. His heart rate upon death was estimated to be 500 beats per minute.
 * Happy Tree Friends: Cuddles pulls this in "A to Zoo" with a helium tank for inflating balloons. Of course, it's Happy Tree Friends, so eventually he manages to impale and inflate his eyeball with it, which later traumatizes Flaky.
 * In an episode of Sealab 2021 in which a Predator was running around the place killing people, Dr. Quinn had the bright idea to mess around with the station's atmosphere in an attempt to hinder the alien aggressor. This ended up pumping a lot of helium into the air vents, which resulted in the crew laughing uproariously over how one of them sounded like a Chipmunk... who is then killed by the Predator, the crew laughing at his high-pitched screams of agony.
 * A Family Guy cutaway shows Stewie doing helium at a birthday party:


 * The Simpsons's Sideshow Bob, while broadcasting his plan to destroy Springfield from inside the Duff blimp; Lisa figured out where he was from the squeaky voice, and when she tells him, he says "Pesky helium! Shoo! Shoo!" and waves his hands, and his voice goes back to normal.
 * Batman the Brave And The Bold: Batman teams up with the Metal Men, a team of periodic element-themed robots, to fight the Gas Gang, a team of slightly-less periodic element-themed animated gas clouds (one of them's named Chloroform) in the episode "Clash of the Metal Men". Helium's only power is to give people Helium Speech. Luckily for him, he's the kind of guy who thinks that gag never gets old. Truthfully though, when used on Batman, it's hilarious.
 * Robot Chicken depicts Alvin and The Chipmunks as having fairly deep voices until Dave floods the recording studio with helium in an attempt to asphyxiate them.
 * In Phineas and Ferb, one of Dr. Doofenshmirtz's evil plans involved filling the entire tri-state area with "Doofelium" making his high squeaky voice lower in comparison, because making his own voice lower would be too much of a hassle. Ended up affecting himself and yelling out his Catch Phrase ("Curse you Perry the Platypus!") in helium speech.
 * Happens once in Fanboy and Chum Chum when Boog's plastic bubble gets filled with helium, right as he's about to punch the titular characters. He notes that it's VERY hard to sound threating with his voice like that.
 * Noah gets one of these in Total Drama World Tour after a serious Groin Attack with a golden statue head.
 * Harold gets one in the finale after Courtney Groin Attacks him, hilariously, he does a literal speech while in Helium Speech mode.
 * The Looney Tunes short "Long Haired Hare". Bugs Bunny replaces an opera singer's throat spray with liquid alum; as he does warm up exercises singing Figaro, each time he says it his head shrinks and his voice becomes higher pitched.
 * In the Screwy Squirrel cartoon "Lonesome Lenny" at one point Screwy sticks Lenny's head into a bucket of alum and he says while his head is shrinking "Why did you put my head in the bucket George?, you shouldn't have put my head in the bucket George, why did you do it?" in a high pitched voice.
 * In an episode of Rocket Power Sam accidentally spreads the "Fiji Flu" to his friends where one of the side effects is having a very high pitched voice.
 * In an episode of Class of 3000, helium is released into the cooling vents as a practical joke. Those affected included Sunny Bridges, Kam, Li'l D, and Principal Luna.
 * Notably, it didn't affect Philly Phil, who thought his voice would sound weird.
 * Falsetto Jones, the villain of the week on Kim Possible, had an extremely high-pitched voice due to a freak accident involving helium (hence his name).
 * Alan the balloon from The Amazing World of Gumball.
 * An early Beavis and Butthead episode had the duo steal balloons from a vendor in order to get high from the helium, after they inhale it and comment how funny they sound they exclaim "Oh no, we're neutered!".
 * Donald Duck: Trope Codifier and he could be the Trope Namer. The Other Wiki even has him as the Trope Namer!

Real Life
"Travis Willingham: "My friends wanna know, 'When you go out of town, what do you do?' 'Oh, you know, eat cake...huff balloons...make a big dumbass out of myself...'" Vic Mignogna: "Don't call me small--(barely avoids headslamming the table) I'll break off your feet and stick 'em on your head!""
 * A new trend around anime conventions: getting voice actors to say their characters' famous lines after inhaling helium. Hilarity Ensues, usually.


 * Chris Sanders.
 * Inversion: sulfur hexafluoride.