What’s That Sound? The Science of Silly Body Noises

Max Velocity

Hey there, Curious Sparks! It’s Max Velocity racing in for another episode—and this one might make your ears wiggle with laughter. Let me ask: Have you ever been sitting super quietly, maybe during storytime or, I dunno, smack-dab in the middle of your school library, when all of a sudden there’s a big GRRRRR coming from your belly? I mean, it sounds like there’s a bear hibernating in your gut, right? That wild noise actually has a real science-y name—get this, it’s called a ‘borborygmus.’ I know, it sounds like some kinda spell from a wizard story, but it’s just the super-fancy word for those stomach rumbles.

Max Velocity

So, what in the world is causing that rumble in your jungle? Well, inside your stomach and intestines, your muscles are always pushing food, liquids, and even air through your digestive tract. It’s sort of like a conveyor belt at a car factory, but way squishier! As your tummy muscles squeeze and move everything along, there’s gas in there too—yeah, we all have some air and gas swirling around our bellies. When the muscles squeeze, the gas mixes in and…boom! There’s that rumbly sound. Sometimes you’re just hungry—and other times, honestly, just thinking about pizza or cookies can set things off!

Max Velocity

Speaking of hungry, there was this one time I was in the library right here in Inventon—totally quiet, not a peep, everyone reading—when my stomach decided to audition for a monster truck rally. I tried to ignore it, but it growled even louder! Some kids looked over and instead of being embarrassed, I figured, why not make this a science moment? I told them about borborygmus, and we ended up giggling about all the ways our bodies make noise. Hey, if your belly’s gonna talk, might as well let it tell a cool science story!

Max Velocity

And you know, our bodies definitely don’t stop at stomach rumbles. Let’s talk burps. Oh yeah, the honorable belch! Why do we burp, anyway? Well, it all starts when you swallow. Every time you eat or drink, especially if you’re gulping down your sandwich too fast or slurping that fizzy soda, you’re sneaking a little air into your stomach. Your body’s not really interested in keeping all that gas around, so—plink!—out it comes as a burp.

Max Velocity

The science behind a burp is kinda like when you open a shaken-up soda. The fizzy bubbles rush out, bringing gas with them. A burp is mostly made of nitrogen and oxygen, but if you’ve chugged a fizzy drink, carbon dioxide usually joins the party. Oh, and here's a wild fact: we're not the only burpers in town! Cows are basically the world champions of burping. No joke, they burp tons of gas every day because they eat so much grass—it’s a total burping bonanza in the barnyard.

Max Velocity

Now, I gotta share this—remember a couple episodes ago when we explored the science of sound? Well, sound is super important for burps, too! Once, back in the Inventon workshop, I tried making homemade soda by mixing a little too much baking soda and lemon juice…and, well, let’s just say what came out was way more burpy than I expected! My burp echoed like a marching band tuba, and everyone burst out laughing. Science projects that fizz are the best, and they remind us how cool—even goofy—our bodies can be!

Max Velocity

Alright, you knew this was coming. The silliest, noisiest, and sometimes stinkiest body sound of all: farts. Yeah, I said it—because science is all about being curious, even about the stuff that makes us giggle and go “eww!”

Max Velocity

So here’s the secret: farts come from tiny bacteria living in your gut. These little guys are party animals! When you eat, especially things like beans or broccoli, these bacteria munch on bits of food you can’t digest. As they eat, they break down that food and release gases—things like methane and hydrogen. Some of those gases slip out as, well, farts.

Max Velocity

Ever noticed how farts all sound…different? Some are squeaky, others are rumblers or the silent but, uh, deadly kind. That happens because the size of the gas bubble, how fast it moves, and even what you had for lunch all change how the sound comes out. It’s like a secret symphony—everybody’s got their own tune! And actually, if you remember when we talked about sound waves in “Sounds Around Us,” farts are just another sound your body can play.

Max Velocity

I’ll tell you, I once pulled a classic whoopee cushion prank at a birthday party (don’t judge!), and everyone cracked up. But then I explained how real farts are made—yup, bacteria and gas and all that—and suddenly, the giggles turned into a science lesson. Best birthday party ever, if you ask me!

Max Velocity

So next time your body makes a silly noise, don’t be embarrassed! Ask yourself, “What cool science is happening inside me right now?” Every sound has a story, and every question could spark your next adventure. Thanks for hanging out with me today on Curious Sparks—I’ll catch you next time for even more wild wonders!