Warbling Whistles Are Weird 

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Presumably, the type of bird that would sound most like a “warbling whistle” would be a warbler, surely?

I love these 2D cut-outs, really makes the explanations more intuitive and easier to understand!

9 minutes in and you've explained 3 questions I've had my life. How do we whistle with our lips? The tea kettle. How does blowing a blade of grass work? Holding a blade of grass in the wedge of your thumbs.. The wedge method. And how do birds whistle, if they don't have similar equipment as us? The bird whistle is their belly. Madness

I have a whole new found appreciation for whistles now. My son LOVED learning about this and so did I! My son was using his whistle while watching this and got so excited when you finally addressed his sports whistle. Love how even the simplest things have an element of physics to them

You're a genius for coming up with these clear 2D representations.

I was about to ask Steve how a normal human whistle works, but then I got scared he would make a 2D transparent version of me!

I love how this video was barely even about the warbling whistle

There's also the scary aztec death whistle that makes a screaming sound, along with other whistles (like hunting ones)

6:00 reminded me of the "grass whistle" where you blow on a blade of grass that you hold tightly between your thumbs. Probably works the same way.

*When it comes to investment, diversification is key. That is why I have my interests set on key sectors based on performance and projected growth. They range from the EV sector, renewable energy, Tech and Health.*

I remember seeing these warbling whistles everywhere on markets in my home town. I absolutely love these things

Like a "normal" whistle, the second / outer hole on the kettle whistle has a wedge that is hit by the air stream - this edge goes all around in a circle.

Steve breaking out into a giggle at "corrogaphone" is hilarious.

A whirly tube is just a Helmholtz resonator. As it spins around, the air passes over the hole; but air does not travel throughout. Theoretically you could just attach a string to a bottle and swing it around and get the same noise as a whirly tube.

2:44 Another interesting bit is that many american WWII fighter planes make a whistling sound while they're in tight turns. This is the exact same effect as the corrogaphone as air is passing over the barrels of the M2 Browning 50. Cal guns.

There is a whole lot of literature about airflow an whistles in the organ building section, even cutaway slow-mo smoke airflow pictures on how the air curls and bends when hitting the organs flutes. Quite fun to watch and definitely interesting. Thx for your work, I really do enjoy your videos!

I literally never saw one of these before until today. I was visiting a museum gift shop with my fiancee and we saw a cute little purple jug and decided to buy it for a friend of ours as a souvenir, and then the guy who works at the museum goes: "Do you know what this is?" and proceeds to show us how to work it. We were blown away, like a couple of kids! Not 6 hours later, I come home to this gem of a video. 😁

4:19 - Boyoyoyoying! :D

I had one of these as a kid in the 70s I always wondered about these... I love the fact that you explain it easy enough for people like me to understand ..and yet don't dumb it down for more intelligent people. Sign of a good teacher .♥️♥️

I received one of those bird whistles at the beginning as a gift. I just assumed it was a poorly made whistle. Now I know to fill it with water. Thanks! :)

my 22 years of curiosity of how a whistle works finally cured

What a great explanation of whistles, I've wondered about this my whole life, and describing the effect with visuals really brought it to life for me.

Gotta love the 2d versions, they are definitely a great help explaining things. This is a neat whistle for sure

you should do a video about how boomerangs return, i understand they create lift through wings but what makes them lift at the front only to turn around

This honestly makes whistling with just your lips that much more impressive to me. We can just intuitively create different shaped cavities to produce different tones without even thinking about it, just adjusting the shape based on our ear and muscle memory.

Dude, you`re my man. I`m exactly like you, always trying to understand those seemingly mundane things, which are not mundane whatsoever, they are incredibly complex and beautiful. I`m a science teacher by the way, and I absolutely appreciate all the see through devices you put together. ( I have built a few myself in the past!) Thank you for this channel.

1:09 man really said ⤵️⤴️

Fascinating dive into the workings and fluid dynamics. Really enjoyed that. Can you use this knowledge to design an entirely novel kind of whistle, I am wondering...

Wow, I have never actually had whistles explained to me before. I just kind of intuited that the shape of the whistle part is important to make noise and the size of the body or cavity usually determines the pitch but I never investigated the mechanisms for why that is the case. It's fascinating that such "simple" devices can function by such a wide range of mechanisms and that even though they are quite distinct from each other, they all boil down to interrupting a stream of air in repetitive but semi-random patterns.

Thanks for this great explanation! I was wanting to make a whistle out of an antler and I found tutorials but nothing explaining how it works. This video helped so much.

i had some of those as a kid!! one of my old gramdmas that passed away when i was younger made me one after if gotten a couple from a school fair and said i liked them a lot (she made me blankets too, one of which i still use today)

I think the corrogaphone is actually the same as the bottle, just without a bottom. Both are air moving across an opening of a cylinder. You could cap one end of the corrogaphone and it should drop in pitch by an octave.

I 3D printed one for my kids and they love it. Really bad idea btw. They whistle in the cars and spill water everywhere 😂

I made a RU-vid video in 2019 where I was recreating bird songs with a synthesizer, I had to use a lot of FM (frequency modulation) to get the right sound, now I understand why! Haha I love this channel

Nice video! I just wanted to say (as you alluded to) you could view all of these whistles as variations of Helmholtz resonators with various shaped cavities and holes. If we adopt the low frequency lumped-element model for these, then a cavity acts as a gas spring and the hole has a column of air that acts like an inertial mass (inertance). The spring acts like a high-pass filter and shows up as a zeroth-order derivative term in the ODE. The column of air acts like a low-pass filter and shows up as the second-order derivative in the ODE. Putting those together we get an acoustic resonance from our makeshift bandpass filter, and this is directly analogous to inductor-capacitor circuits or the simple-harmonic-oscillator. This is obviously oversimplified but I think it provides great physical intuition about what is going on.

The BIC biro cap can act as a whistle. It has a single hole but has an interesting shape like a rocket engine. Produces a super high pitched tone!

I tried designing a whistle before. Failed miserably. Read a couple papers, tried a multi-physics simulation, could not get the desired behavior. What I did find out from failing matches what Mr. Mould said, the turbulence generates a wide band of frequencies (via pressure field disturbances), which changes depending on the qualities of the turbulence. However, this sound is too quiet, but when paired with a resonator (e.g., the green tube that's open on either end counts as a resonator), the frequencies that the resonator resonates with will be amplified and we hear the whistle. My guess is that all whistles are designed differently because turbulent flow is a pain to control (and 3D geometry can all sorts of crazy resonances), let alone turbulent flow generated from the blowing of people who are young/old and different lung capacities. As a result, most whistles aren't engineered so much as they are discovered by mistake or trial-and-error. Some people in the comments mention that musical organs are a great place to start if you want to learn more, which I totally agree with. The line between whistles and instruments is blurry (e.g., ocarina), but I found classical instruments to be far more "engineered" and easier to understand. I always found whistles to be cool because of the sheer variety and wackiness.

This guy has an amazing personality. Very charismatic and the right amount of energy.

I am a nerd and a hockey official, which means I automatically love videos about whistling. So glad you added the pea whistle I was so curious how it worked.

jaguar whistles are pretty interesting too, especially when played by someone who actually knows what they're doing (i.e. the hawkers at mexican tourist spots)

Fun fact that you certainly will find useful: That wedge shape that produces the sound (that can be found on edge-blown aerophones such as the recorder, pennywhistle, slide whistle, sports whistle or indeed the warbling whistle), is called a fipple. It's a fun word. Josh Plotner goes more in depth in his video "Everything is a flute."

After this video I don't know much about whistles because I was fascinated by the way you approach things.

By 7:50 I had completely forgotten this video was about warbling whistles in the first place and was very content to just learn about how whistles worked in general! Very well made video!

The shepherd whistle used in stockdog training is quite interesting too.

Adults everywhere: *Exists* Steve: So I started wondering how this everyday thing works, and it's not as simple as you think. Adults everywhere: No way, I thought we settled this when I was like eight. Steve: *Accidentally creates an experimental quagmire for practical scientists everywhere*

I've always wondered about whistles, but never have it much thought. Rather fascinating. Great episode!

I got one of those in China town ten years ago. We had no idea what it was; it sounded plain but looked cute. Was in my closet and I almost gave it away-- then today your video came up completely random. The brown whistle looked like mine but it is white porcelain and coloured at the wings/crest in blue and pink. This is so cool, it made the sound crisp and clear!! Wow!! I'm going to keep it.

How would using a liquid with a different viscosity affect the whistle's function? Would it still work with something like honey?

love the clear excitement all throughout the video! that's a true scientist right there.

Your work is comprehensively detailed and overarching.💮👍

Steve. Thanks for making rheee videos. Its time, work, effort. Especially this type of content. Thank you. Much respect and appreciation! I love videos like this and the great personality and attitude you put into everything. Thank you.

Fun fact, the word for the regular whistle type is sometimes called a *'fipple'* . I wonder how well those other types of whistles work on wind instruments with holes. I might try 3D printing some and see what happens.

I’d love to see a follow up video explaining how actual birds make their “whistles” (or calls), as well as how humans whistling with just our mouths works

Always love the enthusiasm of your posts

I've had a ceramic one of these since I was 11 years old, bought from a market in Hobart Tasmania. I've always wondered how it worked, thank you! 🐦

When I was a kid my mom had an oversize plastic sports whistle that she would blow to call us home. We had a grade school across the street from our house, large brick building and school yard that we played on. We couldn't hear her (dad could whistle quite loudly) but we could definitely hear the plastic whistle on the other side of the building.

It's taking you an inhuman amount of willpower to avoid the word "fipple hole". The "standard whistle" is called a fipple.

Weird and fascinating! Glad I happened upon this channel. Science behind it is really cool.

aaaaa i love this video. Your explanations are lovely :D they made me understand how the different types of human whistling work: one by making only the tonge move, another by moving only your lips, and another one by moving both to make the pitch u want.

The wedge is a 'languid', the kettle whisle works the same as the ref whistle, exceot that the languid is a tube, note the front disc hole is turned inwards to make the languid. The space between the discs is the resonant chamber A flute with an open end will be twice the frequency of the same flute with a blocked end.

The bird looks like it's chocolate in the thumbnail

great video! thanks Steve. I'm guessing this is similar to how woodwind instruments work. Opening and closing holes to change the resistance and geometry of air in the tube. Enjoying this series of sound objects!

Oh hey i haven't thought about this kind of whistle for a pretty long time, i remember me and my siblings each getting one of these at the county fair when i was around 3 or 4 years old and i absolutely loved it

"In other words, boioioing." -Steve Mould, 2022

Thanks for all this enlightening information! Maybe some time you can try to explain why my eyes appear to glow like a fox's when I look into a steamy bathroom mirror.

Thank you so much for these videos, I also LOVE a good analogy, and the water whistle at 10:20 really demonstrates the power of analogies. After having made a couple analogous, transparent, hydrodynamic models that we can dissect, we can picture in our minds how that whistle probably works, and make educated guesses based on the sound and geometry of previous models that we've seen in action and factually understand the mechanism in motion! (Knowing written theories is great and all, but until I've seen a black hole merger waveform, or a 2d cut-away of a physical model, I can never really be sure if that's how the universe actually works, or how it's been interpreted as working)

10:29 "I reckon that video will be out in, maybe, like, 3 weeks? 4 weeks?" Two months.

First of all: thank you for making me understand all these fascinating things Secondly: you seem like such a likeable guy. Seriously, it's contagious how happy you are about little whistles :)

I am so glad I found this channel. Every video there is at least one little nugget on information that solves a little mystery in my brain. Thanks so much for the amazingly well presented information. You always manage to go from ground level, to complex theory and take the audience with you the whole way. Never boring and never too complex

omg, ive been waiting for this video since i found your channel !! this is amazing

When I was very young, a older cousin showed me how to make a whistle out of a cellophane candy wrapper. Basically, you just unfold the wrapper flat, hold it taught with both hands in front of your mouth, and blow directly into the leading edge. It's incredibly loud and I believe it functions like a reed in a wind instrument. Would this not be an example of basic wind-splitting on a wedge? I assume the leading edge of the cellophane acts like a wedge does, but instead of the air flow switching back and forth from the top and bottom of the wedge based on vortices, the wedge itself deviates at a resonant frequency based on the elasticity of the cellophane.

6:25 Yes, an audible sound is louder than an inaudible sound. Good job Steve 😁

Would be very interested to see the interaction with using a more viscous liquid in the whistle!

Thanks for the video, the warbling whistle made a great gift for my bird-loving mom

Water whistle is EXACTLY like a sports whistle, but with a HUGE number of balls which are connected to each other in such way that it prevents them from bouncing out of the resonating chamber

I had to watch this episode on heaphones. My dogs were going crazy :D Anyway, awesome job again! I love to watch your movies. Because of them I know what I've missed at school - great teacher.

I don’t think I’ve ever thought about how a whistle works before But now I’ve found out it’s actually very interesting

It's 2am and I'm watching a dude explain whistles to me

You are great. Thank you for the good quality content !

All the time, I had this bird whistle in my house, but I never tried blowing it with water...this is so awesome!

The local after-bar pizzeria has these T-shaped water bottle caps with holes on both sides, and when you pour water from one hole it makes a bird chirping sound from the other one. It's been the wonder of many friday nights, now I know how they work!

What a fun video :) Thanks Steve! Youre starting to remind me of that guy who reviews all the old fashioned toys on RU-vid, and is always so enthusiastic about them haha 😊

A beautiful explanation and humble enough to agree that there are other factors that are working, which is true!!

0:01 - Yo Steve, Make this your permanent intro!!!!!

Lovely to see how much joy Steve gets from something so simple as playing with whistles.

The corrugaphone works just like blowing on the bottle. Instead of blowing over the hole, the tube moves its hole over static air giving us the same effect. Great video and explanations!

Now I want an explanation of the Aztec "death whistle" 4:08 Why does a stream of air have momentum? The particles in the stream, sure, but their momentum is mostly forward and maybe slightly up. But if the airstream is fast enough, most particles with some upward momentum will already have moved forward when the airstream is in the middle. So there would be only a tiny bit of momentum at high flow rates. Or am I missing something here? Edit: Ohh, my point just means that the faster the airstream, the higher the frequency or otherwise there would be no oscillation as the particles move away too fast.

this is truly eye opening! ive always wondered how these whistles work in particular how my 7th grade recorder worked, what a great video

I have a collection of helmholtz resonator flutes in the form of various ocarinas. Their frequency is determined by the speed of the airflow, total surface area of the holes, and volume of air inside the resonator. Which is quite a number of variables compared to a recorder.

This unlocked a old memory of my grandparents giving me one of these

Steve, thank you! You had me at harmonics and resonance! You've done it again, helping me better understand principles. Thank you for sharing the answers you find through curiosity. I sure appreciate the quality of your content.

that eye flutter 0:13

I've always wondered about whistles, thank you Edit: That was amazing! Thanks!

Your such great science videos gives me great knowledge in science. And this video was very informative for me. Thank you for such a knowledgeable video.

I used to love these as a kid! Thanks for once again making me ask questions and answer them!

The master at explaining anything! love these breakdowns of simple household objects!

Thank you for the content! Amazing

The whistle demos are for some reason hilarious 😂

6:01 , you may have gotten it to whistle if you had enclosed it within a 2D space like you did with the other whistles. Very much surprised me that you didn't try that...