Why Does Helium Change Your Voice?

"I've been talking down to a lot of you. And i want to take the time to let all of you know how good it feels to talk to you from a superior place." "When is this person whoever sends these fackin things going to realize i don't want any o f your up dates? All right, so that's fascinating. Who knew that? Ime?" The speed of sound at sea level in helium is 20 times faster than for air.