How do we make sounds that are both high and low?

How do we make sounds that are both high and low?

Professor Gizmo (Amazing Science Presentations) gives expert video advice on: How do we make sounds that are both high and low?; How do my eyes play tricks on me?; What is the difference between a solid, a liquid and a gas? and more...

How to make sounds high or low; this is a neat little topic to take look at. Think about a piano or a guitar (especially a piano); if you take a look at the longer strings on a piano, they're usually the lower notes and the shorter strings inside the piano, they are the higher notes, and we can show you that with a couple of items. This is a slide whistle. Now, we blow into the slide whistle, and there's a small chamber in here where the air vibrates. If we make that section where the air vibrates longer, it makes the note lower, and if I make it shorter, it makes the note higher, so it sounds like this [Professor Gizmo blows the whistle, pulls the slider down and makes a sound that starts high and becomes low]. You can see how the size of that space in there changes. It's easy to remember because both start with an L; longer is lower. Now this, is a little demonstration that you could do at home, that you would be very careful with, but it's just simply a straw. I like to call it this "the straw oboe". Now, I flatten this end out just slightly, and pull it between my teeth gently to flatten it out. Then, you take scissors and you cut a little wedge on both sides like this, and like this [he cuts the straw] and then you blow into this end [a noise is produced]; pretty low sound, right? Now, we can change that by changing the length of this tube; remember longer was lower, so if we make it shorter its going to be higher. [Professor Gizmo blows into the straw. As he is blowing he takes the scissors and snips off sections on the straw, making the sound higher with every snip. He accidentally snips his nose] Oh! You got to be careful.