Why Inhaling Helium Changes Voice?

That's because helium is so much lighter than air. When sound waves speed up but their frequency stays the same, each wave stretches out. ... It's a gas that is much heavier than air, so when it is inhaled, it shortens sound waves so the lower tones in the voice are amplified and the higher ones fade out.

Is it safe to inhale helium from a balloon?

Breathing in pure helium can cause death by asphyxiation in just minutes. Inhaling helium from a pressurized tank can also cause a gas or air embolism, which is a bubble that becomes trapped in a blood vessel, blocking it. The blood vessels can rupture and hemorrhage.

Will your voice go back to normal after inhaling helium?

If you've ever breathed helium and heard the sound of your voice, you've probably noticed that the effect wears off quickly. That's because the effect only lasts as long as there's helium around your vocal cords. As soon as regular air replaces the helium, your voice returns to normal.