Have you ever wondered what sound is? How you can hear the things around you? Well today we’re going to tell you how sound works, and some interesting activities you can do with this amazing sense.
First of all, what is sound? What’s happening when you wade through fallen leaves, or listen to birds singing?
When you make a noise, you send vibrations through the air in the form of a pressure wave. All the air molecules bump into each other in turn. Then they bump into our eardrum and cause it to vibrate. Our brain interprets that as sound.
Let’s use an elastic band as an example. When you pluck an elastic it makes a twanging sound and you can see it vibrate. The tighter you pull it the faster it vibrates, the closer together the peaks of the waves are, and the higher pitched it sounds. Pitch is basically how high or low a note sounds. For example, a safety whistle is a very high pitched noise, whereas thunder has a very low pitched noise.
Some animals can take this sense and use it in amazing ways. For example, bats use sound, instead of sight, to see in the dark.
Bats send out a very high pitched noise (so high pitched that humans can’t even hear it) that bounces off objects and comes back. They can tell how far away an object is by how long it takes for the sound to come back to them.
A really easy activity to do with the noises around you is to create a sound map. All you need for this project is a piece of paper, a pencil, and about ten minutes.
First, find a place to sit. This could be a balcony, a backyard, or a local park. Anywhere will be fine. If it’s raining or snowing then you can do it sitting on your couch, but try to get outside if possible.
Once you have a spot, get out your piece of paper and your pencil. Draw yourself at the middle of the page if you want, or just a dot to represent you. Then draw all the sounds you hear around you. You can draw what you think made the sound, or write how you hear the sound. What ever you feel comfortable with.
Home Made Music
Have you ever wanted to make a musical instrument? Well now you can! Here are some very simple instruments you can make at home. For this next project all you need are a few things most people have around their house.
1. Musical Comb
Materials: comb, wax paper.
Instructions: wrap the paper around the comb and tape in place.
How to use: place the comb just touching your lips and sing into it. You should hear a buzzing tone. You can change the tone by changing the pitch you sing.
2. Water Glass Xylophone
Materials: several identical water glasses, water, chopsticks (optional).
Instructions: fill the glasses with varying amounts of water.
To use: tap the glasses lightly with the chopsticks. See how different amounts of water produce different notes.
3. Shaker Bottle Maraca
Materials: any small plastic container with a secure lid, any small grain (eg. rice or lentils), a funnel or a rolled cone of paper.
Instructions: fill the container most of the way with the grain (using the funnel to prevent spills). Screw on the lid.
To use: shake the container.
4. Elastic bands
Materials: several elastic bands of various sizes, any container you want (eg. jar lid or drinking cup).
Instructions: stretch the elastics around the container.
To use: pluck or strum the elastic bands.
We hope you enjoyed reading this and making your own sound maps and musical instruments
Lily O. & Zaira S. are members of the High Park Rangers youth volunteer stewardship program.