How does whistle make sound

When you blow across a bottle, the pressure in the moving air stream is decreased, and some air is "sucked out" of the bottle into the low pressure air stream. However, the extra air merging into the airstream bends the airstream away from the mouth of the bottle, which reduces the amount of "suction.

The air inside the bottle has a natural frequency of vibration, which depends on the size and shape of the bottle. This vibration is excited by the sudden pressure change at the mouth of the bottle, and after half a cycle of vibration it acts to suck some air back into the bottle.

That pulls the air stream you are blowing across the bottle back towards the mouth of the bottle, and the cycle repeats. The critical parameter here is the time it takes the blown air stream to travel across the mouth of the bottle , compared with the time for one vibration cycle of the air inside the bottle. If the two time intervals have the correct relationship, the oscillations can build up in amplitude.

This explains why if you blow gently low velocity , you produce no sound at all, and if you gradually blow harder, suddenly the sound starts. Depending on the geometry of the whole system, if you blow very hard the sound may "jump" to a different higher frequency. In fact it is possible to adjust an organ pipe so that it will successively produce a sound at with 3 or 4 different pitches, depending of the wind pressure and therefore the air velocity used to blow it.

The vortices are simply by-products of the oscillating air stream hitting the edge of the bottle mouth. The "wrong" explanations start from the correct observation that simply blowing a jet of air through a nozzle can produce a pattern of vortices, which may repeat at a definite frequency. But for the geometry and blowing pressure of a typical whistle, the frequency of that vortex pattern if it exists at all is very different from the frequency of the sound produced by the whistle, and it's hard to invent a good reason why the vortices should cause the sound.

Air in a chamber resonates like a spring: It has mass and springs back when compressed or decompressed. As it resonates down, it deflects the air stream down into the opening, pushing the air down more.

As the air inside springs back, it deflects the air stream upward, so it's no longer pushing down. It also drags air away from inside by the Bernoulli effect, helping to pull the air inside up. Any vortexes formed are incidental. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Learn more. Most people know that elephants trumpet. But they also make other noises such as squeaking, chirping, rumbling and roaring sounds. Elephants trumpet when they are excited or stimulated. An elephant makes trumpet sound by pushing air through its trunk. How do you spell the sound An Elephant Makes? Elephants trumpet when they are highly stimulated. While most vocalizations are made with the larynx, a trumpet is produced by pushing air through the trunk.

Trumpeting elephants may be excited, lost, angry, playful, or surprised. Why does my car make a whistling noise when I press the gas? If you hear a whistling sound while driving, there are a few different places you can check out to find a probable cause.

The most common reason for this noise being made is a vacuum leak, due to worn or cracked hoses. What does a bad wheel bearing sound like? The most common symptom with a bad wheel bearing is a loud noise coming from the tire or wheel of the vehicle.

It will sound like metal grinding on metal and will get louder as the vehicle goes faster. The air escapes out the little hole in the end, making the noise you hear. The frequency of the sound is dependent on the length of the whistle. The longer the whistle, the lower the pitch will be. The ball inside the whistle is not necessary for the whistle to work but serves a purpose. A whistle without a ball has a flat tone that may get "lost".

In an American Whistle the ball rises and falls as it is pushed around by the turbulence. Hi Sep 28, Oct 3, That's okay, Hi. Some people can whistle and others can't. Feb 8, Thanks for sharing your thoughts, Ray! Vienna Oct 4, It's easy now I have tried thanks Wonderopolis for all your help.

Oct 5, Thehelper Jul 21, Jul 21, Keep practicing! Wonderopolis May 4, Elizabeth Thompson May 21, I can't whistle! I'm almost 12, and I still can't whistle! I know 5 years olds that can whistle! Well I used to know how to whistle.

I say whistle too much :D Well anyways, everytime I try, It never works! Have a nice day :. Wonderopolis May 21, Julianne Apr 29, Dear Wonderopolis, People keep trying to help me whistle do you have any tips? Hello, Stephanie! But the good thing is that I can whistle so know anytime I hear that song I can whistle and think about this website and the video. Hi, stephanie! Wonderopolis Apr 29, Hi it's me again, Jaden I have a question for you: how did you make this website and why did you pick that song to do for this video?

I think that this wonder can realy help poeople whistle. Everyone can learn how to whistle just from looking at this wonder. People and kids everywhere can now whistle even if kids at school are on the website they can still learn how.

Thanks wonderopolis. I will always come here for info. Wonderopolis Apr 16, Kate Apr 12, Wonderopolis Apr 12, Wonderopolis Apr 8, A for effort, Mjscott!

We hope you'll keep trying, so then you can whistle while you Wonder! Belyndise Apr 8, I don't know how to whistle. But this kind of helped!! Wonder Friend Sarah Apr 8, Hello wondermans! I'm Sarah from team cassie a couple years ago. I'm in 6th grade, almost done and I'm loving it!

I like your wonders, your 88 away from your th wonder! Also I love your website. A fun way to learn is what I think! You all must love the concept of wondering! Annie Apr 8, I whistle so much! I enjoyed this wonder wonderopolis!!! I think tomorrow's wonder of the day is about dinosaur fossils.

Cassidy Apr 8, I can't whistle but I'm going to keep trying. I can't wait to find out what tommorow's Wonder is! Alexandra Apr 8, Sofie Apr 8, I've tried to whistle before, but I can't. Zitar's Class Apr 8, Whistling is really awesome to do!

Our guess for tomorrow's wonder is how are fossils made? Miss Fleenor Apr 8, We did not know that both your tongue and lungs help you to whistle. Krysten We already know that many people can make music from whistling. Emma Anyone can whistle Cameron We know that it takes lots of practice, because some of us still are not able to whistle.

Neleh We learned that a whistle is a high, shrill tone. Malkam Some whistles are with our fingers, and some are not. Deanna Allison Apr 8, How can I print out a specific wonder and the accompanying activities? W's Readers Apr 8, We are wondering who invented whistling and when it was first recorded? What is the age most kids learn to whistle? Is there a record of the loudest or the longest whistle? How do you whistle with your fingers in your mouth?

I loved this wonder it helped so much now I know how to whistle even better! Can't wait til the next wonder. Berkleigh Apr 8, This was a cool wonder! I have tried to whistle, but I can't. And yes, like Blakeleigh said, our brother can whistle, and he sounds like some kind of bird when he does it. And our older sister can, too. Thank you for today's wonder! Devan Apr 8, Thanks so much, Devan, we're glad this Wonder made you smile! That's still a whistling talent, Tanner!