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It doesn’t matter if it’s an aluminum or rubber balloon. They’re sold at party centers or you could rent a helium tank to fill up your own balloons for a special event. You’ll know a balloon is filled with helium if it floats. Helium is lighter than air, so it naturally rises. If a balloon stays down near the ground, it doesn’t have helium in it. If you don’t have a safety pin, a pushpin or sewing needle will work just the same. Use the pin to prick the balloon and create a really small hole, and then squeeze the hole shut with your fingers to keep the helium from escaping until you’re ready to inhale. If the balloon is inflated but not knotted, you don’t need to poke a hole in it. You can simply suck the air directly from the opening. Don’t just hold the helium in your mouth—breathe it in like you would a normal breath of air. Just 3-4 seconds should be enough to fill your lungs with helium.  It helps to exhale fully before inhaling so that you can get as much helium into your lungs at once as possible. Helium doesn’t have an odor, taste, or smell, so you really won’t be able to tell that you’re breathing in an element different from oxygen until you try to speak. As soon as you’ve finished inhaling, start talking! The helium-effect will only last for 5 seconds or so, so don’t wait too long. What you say is totally up to you! Have fun and come up with unique phrases or just repeat your name over and over again to hear how you sound. If you suck too much helium at once or for too long of a period of time, you can hurt yourself. So between each inhalation of helium, take a few minutes to breathe normally.

Summary:
Get a balloon filled with helium. Poke a small hole near the balloon’s knot with a safety pin. Put your mouth over the hole and inhale while squeezing the balloon. Say something funny to hear how the helium affected your voice. Wait 2-3 minutes between each helium-inhale to rebalance your oxygen.