I currently have both children at home given the situation in the UK at the moment. My eldest is set work from school which occupies him (and me with cajoling him to get back to it and helping him understand what he is supposed to be doing), but not the whole day. So we are back to trying to find things to do to pass the time- their baths get earlier and earlier!!
I was looking at Pinterest the other day and came across a post from DadLab looking at the science of sound. You can find the post I saw here.
This immediately appealed to me because my boy loves science and it’s another route into getting him interested in music and making music. Long term readers will also know that we love making DIY musical instruments and this fitted beautifully with that as the sounds made we’re just like a slide whistle.
A slide whistle looks like a recorder, but it has a thin pole that goes through the middle of it. To play the slide whistle you blow into the mouthpiece and move the metal pole up and down. This changes the pitch that is played, like this
Now, the DadLab video is pretty self explanatory about how to make this whistle, but here is a step by step guide. To make the DIY slide whistle you will need:
- A straw, more than one if there are a few of you doing this together.
- A pair of scissors (a grown up will need to use the scissors for this as it would be extremely difficult to do, if not impossible, with safety scissors)
- A glass or cup of water, pretty full.
Cut through the straw about 1/4 to 1/3 of the way down the straw. You don’t want to cut all the way through, leave about 1/4 of the straw still attached.
Put the straw into your glass of water. The cut part of the straw should not be submerged into the water. I had quite a full glass of water when I did this with my two. My 3 year old can largely be trusted not to always knock a glass over, but I must admit to hovering right over her when she went anywhere near the glass! You do need plenty of water in the glass/cup to demonstrate the effect, so if your little one is very clumsy (that would be me still!) then perhaps you should just demonstrate this or use a plastic cup sat in the middle of a tray.
Your straw should bend a little where you have cut it allowing the air to escape. Blow through the straw gently and as you do, listen carefully to hear the pitch change from low to high and back again just like a slide whistle.
When my children had a go, they had great fun not only making the sliding sounds but also just blowing bubbles in the water. Our table was quite soggy within a few minutes!! As it was just water that I used it was easy to clean up with a tea towel afterwards.
When playing it we talked about whether the heard a low or high sound when the straw was at the top of the glass or the bottom of the glass.
Sound is made from waves and generally the further a sound wave has to travel, the lower the sound it makes. If the sound wave has a shorter (or thinner) distance to travel, then a higher note is produced. You can see this is musical instruments – a large double bass with very long strings will sound lower than a violin that has shorter strings. So with this slide whistle as the straw is at the top of the glass the air, and so the sound, can travel all the way to the bottom of the glass making a lower sound. When the straw is moved to the bottom of the glass, then the air only has a short distance to travel down the straw, and so it makes a higher sound.
This was a fun experiment, and a very quick and easy DIY instrument to make.