Ask a Southeastern Idaho Scientist

That is a very interesting question. Sound travels at different speeds in different mediums. In a gaseous medium sound travels faster in lighter gasses, and the faster the sound travels, the greater the frequency or higher the pitch of the sound. Since helium is about seven times lighter than air, sound travels about two times faster in helium than in air. When you breathe helium, sound travels faster in your throat and mouth making the pitch higher so you sound like “Donald Duck”. Conversely, breathing argon (a heavy gas) makes a lower pitch sound or “Goofy” voice.

As a Pharmacist, I am concerned about the safety of breathing helium. Helium is chemically inert and will not harm you. However, helium will displace oxygen in your lungs eventually depriving your brain of oxygen, which may make you faint. I have heard of people breathing helium from the tank instead of a balloon. The pressure of the tank could cause the tiny air sacks in the lungs to rupture causing severe problems. Lastly, helium used to blow up balloons could be contaminated with other chemicals that could be harmful. All in all breathing helium is not a good idea.