Speaker 1: Welcome to brain Stuff, a production of iHeartRadio. Hey brain
Speaker 1: Stuff Lauren voblabomb here with a classic episode from our
Speaker 1: podcast archive. In this one, we get into the weird
Speaker 1: science behind a goofy party trick using the helium from
Speaker 1: a balloon to make your voice go squeaky. Hey brain Stuff,
Speaker 1: Lauren vogel bomb here.
Speaker 2: Today's question is why does helium make our voices go
Speaker 2: all squeaky? And to answer it we have to ask
Speaker 2: three other questions. What is air, what is helium? And
Speaker 2: what is your voice? Note here at the top we
Speaker 2: cannot technically recommend inhaling helium to play with your voice,
Speaker 2: and even if we did, you probably shouldn't take our
Speaker 2: medical advice. But if you're going to only pull from
Speaker 2: a balloon, not a helium tank, tanks contain compressed gas
Speaker 2: that'll pop your lungs, and only take short breaths and
Speaker 2: make sure you get some good old regular air in
Speaker 2: between goes so that you don't suffocate. Okay, So back
Speaker 2: to our questions. First up, air. Air is a gaseous
Speaker 2: molecule soup yep, it seems real thin, but it's chalk
Speaker 2: full of stuff when it's dry. Air is about seventy
Speaker 2: eight percent nitrogen, twenty one percent oxygen, nearly one percent
Speaker 2: are gone, and a wee bit of a bunch of
Speaker 2: other things carbon dioxide, neon, helium, methane, etc. It can
Speaker 2: also contain some water vapor, maybe zero to three percent.
Speaker 2: Your voice is the vibration of that air soup created
Speaker 2: by sound waves. When you speak, saying, or yodel, you're
Speaker 2: pushing air in your lungs out through your throat past
Speaker 2: your vocal cords. You can vibrate, loosen, and pull taut
Speaker 2: your vocal cords in a number of ways to make
Speaker 2: a number of different frequencies of sound. Because the vibrations
Speaker 2: are periodic, meaning that their motion is repeated after an
Speaker 2: interval of time called a period, the frequencies produced by
Speaker 2: your vocal chords are harmonic. The harmonic frequencies that your
Speaker 2: vocal chords create are called your voice's pitch. You can
Speaker 2: manipulate other parts of your mouth noise maker, your throat, jaw, cheeks,
Speaker 2: and tongue to manipulate the way those harmonic frequencies bounce
Speaker 2: around inside your head, that is, resonate before they leave
Speaker 2: your mouth. This gives more power to the frequencies as
Speaker 2: they add to each other, and it creates your voices. Timber.
Speaker 2: Timber is one of those great words that's defined by
Speaker 2: what it's not. It's not how loud your voice is,
Speaker 2: and it's not your pitch. It's any other quality that's
Speaker 2: different if two sounds, loudness and pitch are the same. Okay,
Speaker 2: all of that makes more or less sense. On to helium.
Speaker 2: Helium is an element that's mixed with little air to
Speaker 2: fill balloons because helium is less massive, a colloquially termed
Speaker 2: lighter than air, and thus makes balloons float in air soup.
Speaker 2: It also helps that helium is inert. It doesn't like
Speaker 2: reacting with other elements, so it's not likely to cause
Speaker 2: an explosion or catch fire or anything else that we
Speaker 2: don't like our balloons to do. And it stays a
Speaker 2: gas at a wide range of temperatures. But yeah, it's
Speaker 2: pretty light. How light are we talking? So light? Helium's
Speaker 2: standard atomic weight is just four point zero zero three.
Speaker 2: In comparison, nitrogen and oxygen are more than three times
Speaker 2: as massive, with standard atomic weights a fourteen point zero
Speaker 2: zero seven and fifteen point nine nine nine, respectively. So
Speaker 2: when you breathe in helium instead of air. You're filling
Speaker 2: your lungs and head cavities with these we atoms that
Speaker 2: get pushed around like all heck by sound waves like
Speaker 2: Oz's scarecrow in a mosh pit. The atoms that make
Speaker 2: up normal air don't oscillate as quickly because they're more massive,
Speaker 2: like the tin man in a mosh pit. The practical
Speaker 2: outcome of this is that sound waves travel through helium
Speaker 2: much faster than they do through air, about three times faster.
Speaker 2: Since the sound waves are traveling faster than usual, their
Speaker 2: resonances inside your head cavities occur at higher frequencies. Think
Speaker 2: of it like a pool table. If you started playing
Speaker 2: with ping pong balls instead of pool balls and hit
Speaker 2: them with the same that fly around the table, smashing
Speaker 2: all into each other at much higher speeds. That means
Speaker 2: that less resonance is happening at the lower end frequencies
Speaker 2: of your normal air driven voice, meaning the lower frequencies
Speaker 2: have less power to them, meaning that the sounds that
Speaker 2: emerge from your head cavities and out of your mouth
Speaker 2: are the higher frequencies. You sound squeaky like Donald Duck. Ducks,
Speaker 2: by the way, get their squeaky quack by virtue of
Speaker 2: having a much shorter vocal tract and less headspace for
Speaker 2: air than humans. Note that the helium doesn't change the
Speaker 2: wavelengths of the sounds emerging from your vocal chords. Doesn't
Speaker 2: affect your pitch. If you sing a particular note on
Speaker 2: regular air and then on helium, it will be the
Speaker 2: same note. It'll only change your timber, and specifically the
Speaker 2: timber of your vowels.
Speaker 1: Today's episode is based on a script I wrote for
Speaker 1: the brain Stuff video series back when that was a thing.
Speaker 1: Brain Stuff is production of iHeartRadio in partnership with how
Speaker 1: stuffworks dot Com and is produced by Tyler Clay. Four
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