Simple home experiment to discover the joy of sound waves

While other kids may be concentrating on what they see, your kid might be focusing on what she can hear. Has your kid ever wondered how a musical instrument manages to generate such wonderful sounds? If yes, it’s time to introduce her to the science of sound, musical instruments, and even how humans respond to music. We are here with a simple, do-it-yourself (DIY) musical STEM experiment that will help your kid create their own musical instruments out of drinking straws.

What you’ll need 

Plastic or paper-made drinking straws
A pair of scissors
An electronic keyboard, or other musical instrument that can produce a scale of notes (optional)

How-to 

Here’s a step-by-step guide to the experiment. Help your kids follow these. 

Cut one of the two drinking straws so that it is half the length of the other straw.
One of the straws should be flattened about one inch at one end. To flatten it, you can use your teeth or pinch it between your fingers or fingernails.
Make two small, angular incisions on each side of the flattened end using scissors. When flattened, the end of the straw should resemble a "V" shape. However, the pointed tip at the end should have a short, uncut segment left.
Repeat this to the other straw so that both have small, angular cuts on one end.
Insert the cut end of one of the longer straw into your mouth. Position the cuts so they are just inside your lips. Then curve your lips down and inward a little and apply light pressure on the straw with your lips.
Blow the straw away. What do you think you hear? A tone should be produced by the cut ends vibrating. It's possible that you'll have to shift the straw about a little to get the best position for making your musical note. To produce a consistent, single note, it may require some practice and multiple attempts.
Now blow through the shorter straw using the same method. Again, you may need to try blowing through the straw a few times to make it produce a constant, single note.
Note what do you're hearing this time. What do you think of it in comparison to what you heard with the longer straw?
If you have a piano, electronic keyboards, or other musical instrument, compare the notes on the straws to the notes on the real musical instrument.

How were the sound waves produced?
Sound moves through the air in waves that are invisible to the naked eye. The frequency of a sound wave is the rate at which it causes the air it travels through to vibrate. The pitch rises as the frequency rises. Hence, the shorter straw produced a higher frequency sound wave than the longer straw, and the shorter straw produced a higher pitch. Since the shorter straw was half the length of the longer straw, the shorter straw generated twice the frequency of the longer straw.