How Inhaling Helium Changes Your Voice

Is this dangerous??

"The pitch of your voice is related both to the shape of your throat and to how fast the vocal cords vibrate'" says Dr Jennifer Anderson, director of the voice-disorders clinic at St Michael's Hospital in Toronto.

"When the vocal cords vibrate, the air in the throat and mouth is set into motion. The shape of the throat creates different sound peaks, called resonance peaks."

Speed of sound also determines pitch. In normal air, sound travels at 360 meters a second. In helium, which is lighter, sound travels at about 900 meters a second.

With helium, the vocal cords vibrate faster, and the resonance peaks in the throat are about 2.5 times higher, Anderson says. "These combined factors contribute to the cartoon-like voice effect when you speak with a lungful of helium".

However breathing in helium is not entirely safe because it replaces the normal balance of oxygen and nitrogen in the lungs. In large enough amounts, it can force the oxygen out of the lungs, causing suffocation and other damage. In rare cases, helium bubbles may form in  blood vessel, causing a stroke

Facts of Life,Rd