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Why does helium - which is what this balloon is filled with - make your voice sound high? |
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Kate's voice was very high-pitched because she'd been breathing a special mixture of helium which is safe. Never breathe helium from a balloon - it's very dangerous. |
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Did you know that helium is also used by divers? At great depths, the air which we all normally breathe becomes poisonous. It could actually kill you! |
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So divers breathe a special mixture of helium and oxygen which is safe. This does cause a problem - the divers sound like Donald Duck! |
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So why does helium make a voice sound so squeaky? Well, it's the same reason that makes a helium-filled balloon float. |
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Because of the way your voice works, the quicker the sound of your voice travels through the air, the higher it sounds. Helium allows your voice to travel very fast, which is why it sounds so high. |
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It's the same with these two jars. One is filled with water, one with gel. |
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When they are tipped over, the ball in the water travels much faster than the gel. That's because the water is much thinner than the gel. |
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Helium is much thinner than air, so your voice can travel much quicker and it sounds very high. But if we were to breathe in a gas that was thicker than air, our voices would get lower. Oo-er! |
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Divers breathe so much helium that their voices sound very high. Which is where this gadget comes in useful - it's a helium speech unscrambler. It loads the sound of a divers voice to make it much easier to understand. |
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Just by pressing a few buttons, it makes a divers voice sound normal. It lowers the sound of the voice to make it perfectly clear to understand. |
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