What is the Physiology of the Cartoon Helium Voices being left on my Voice Mail?

[Cacia]

...I am worried for my friend.

I heard that you can get an AGE from huffing He. :no

WASHINGTON, Aug. 28,1996-- A healthy 13-year-old boy experienced a potentially fatal ending to some party fun when he inhaled helium gas directly from a pressurized tank. After inhaling the gas at a party, the boy became unconscious, and had a seizure for ten minutes. When emergency physicians saw the boy in the emergency department, they discovered that he had suffered a cerebral gas embolism -- a temporary stroke caused by air bubbles in the blood stream -- in addition to lung damage caused by rapid, uncontrolled lung expansion.

:11doh: True?

 

[do it easy]

What kind of person would huff on helium and leave messages on people's voicemail?

It sounds like this kid had a lung overexpansion injury- probably from the helium entering his lungs too quickly at high pressure.

 

[Rick Inman]

Put your lips up to a 2800psi tank and crank open the pressure and you're asking for trouble.

That's why we do it real slow...

 

[dlndavid]

I prefer N2O

 

[do it easy]

As far as the voice change when breathing helium, the gas is less dense so the vocal cords vibrate faster and the voice sounds higher pitched. Of course, there is a danger of asphyxiation if there is no O2 mixed in with the helium.

 

[spt29970]

Put your lips up to a 2800psi tank and crank open the pressure and you're asking for trouble.

That's why we do it real slow...

This almost certainly has nothing to do with the gas being helium, just being pressurized. That's why we use a regulator!

 

[Cacia]

the gas is less dense to the vocal cords vibrate faster so the voice sounds higher pitched.

ahh ha. I wondered about that. Ya'll are faster than Mr Google.

 

[spt29970]

As far as the voice change when breathing helium, the gas is less dense so the vocal cords vibrate faster and the voice sounds higher pitched.

This is a common misperception. The vocal cords don't change their vibration appreciably in the presence of helium.

The perceived tone of a voice is actually quite subtle. The thumbnail view is this. Your vocal cords make a buzzing noise which consists primarily of a fundamental frequency and a series of harmonics. These frequencies are set by the length and tension of your vocal cords. This buzzing noise excites resonances in your vocal tract. These resonances are set by the shape of the vocal tract (which you can change with muscles to vary pitch), and the speed of sound in the gas. Think of these resonances as being like the tones generated in an organ pipe.

When you breathe helium, you don't change the vocal cord buzzing appreciably, but you do dramatically alter the resonances in your vocal tract because the speed of sound in helium is much higher than in air (due to the reduced density as "do it easy" suggested). The net result is that the resonance are much higher frequency.

Summary: Vocal cord vibration doesn't change, but resonances in the vocal tract do.

For more details, there is an excellent reference at
UNSW Resources (PHYSICS!) - Physics in Speech

 

[do it easy]

Thanks for clearing that up

 

[SteveAD]

the key is the phrase "directly from a pressurized tank" if someone wraps their lips around the tank valve and cracks it open, it doesn't matter if the tank contains air, 02, He, or acetylene, if you blow high pressure gas into your lungs you can get barotrauma which could result in a CGA or AGE. Breathing any gas thru a demand regulator, the only concerns would be suffocation if breathing an inert gas (like He) with insufficient 02 or poisoning, if the gas is inherently toxic.