No. 8 Thinker

How About a Sound Sandwich.

For this sound experiment you will need the following:

• Two large popsicle sticks

• 1 large and two small rubber bands

• Scissors

• 2 bendy straws

The first thing you are going to do is cut the short end of the straws, half a cm before the bendy part. Then you are going to get the large rubber band and stretch it over one of the popsicle sticks from one end to the other. Once you have done that, you need to get one of the small pieces of straw that you have cut and sandwich it between the two popsicle sticks. It should be towards one end of the popsicle sticks and have both ends sticking out either side. You will use one of the smaller rubber bands to keep the ends together. Then you will do the same thing at the other end with the other small piece of straw, and use the other small rubber band, twisting it around the end of the popsicle sticks to hold those ends together. Make sure that the rubber bands are on the outside of the straws.

When you have done that, you are ready to play your instrument. Bring the sound sandwich to your mouth so the popsicle sticks are horizontal, and blow through the thin space in-between the popsicle sticks. You will find that your air will vibrate the larger rubber band and produce sound. You could use smaller rubber bands and hear what different sounds would be made.

How to See Sound

For this experiment you will need:

• Cling film / Plastic wrap

• 100’s & 1000’s (Sprinkles)

• Scissors

• Bowl and plate

To start off with, you need to get a good length of cling film so that it stretches over the bowl. What you are trying to do is create a drum. In this experiment, the cling film acts like the skin of the drum. You need to ensure that the cling film is stretched nice and tightly over the bowl. Once you have done that, get the 100’s and 1000’s, press lightly with the tip of your finger in the middle of the cling film, and pour some of the 100’s and 1000’s onto the cling film. When you slowly release your finger, the sprinkles should remain gathered in the middle.

Time for the exciting part. If you talk directly in front of the bowl so your voice travels across the cling film, you will notice that the 100’s and 1000’s begin to move. You will find that the vibrations of the sound are moving the 100’s and 1000’s. You might think that it is your breath that is moving them – think again! Start to hum and see what happens. Does the pitch of your hum change the movement of the 100’s and 1000’s? Move your head closer then further away to see if the movement of the 100’s and 1000’s changes.

This is a simple experiment to demonstrate how sound travels.

Water Xylophone

For this experiment you will need the following:

• 4 glasses or mason jars

• Water

• Food colouring (optional)

• Wooden sticks

To start, fill the glasses or mason jars with different levels of water. It is important that each one has a different level for best effect. The more water that you add the lower the sound and the less water you add the higher the sound. Test out the sound of the different glasses as you fill them, by using the wooden sticks and tapping the glasses. You can add the food colouring to each glass. You might like to try and match the food colour the best sound.

You would have noticed that when you tap the empty glasses or jars, they made the same sound. By adding the different amounts of water, you begin to notice the changes in noise, sound and pitch.

Create a paper cup and string phone.

You need: 2 paper cups, a sharp pencil, string

Start by cutting a piece of string, you can decide on how long you would like it, however, 15 metres is a good start. With the pencil poke a small hole in the bottom of each cup. Push the string through each end and tie knots at each end, which will stop it from pulling through the cup. With your buddy, move into a position holding the cups at the distance of the string, making it tight. Take turns at talking into the cups. To hear what is being said, put the cup to your ear and listen.

How does this work? When speaking into the cup, it creates sound waves, which are then converted into vibrations. Vibrations move along the string, which is converted back into sound waves at the other end so that your friend can hear what you said.