Why does our voice go higher when we breath in helium?

Question

When you breath in helium it makes your voice go higher and I want to know why.

Answer 1

It is because helium is lighter than air.

Air is about 8/10 Nitrogen which is seven times havier than helium. This means that a compression (sound) wave propagate faster through helium than it will through air.

Here is full explanation:
http://www.physlink.com/Education/AskExperts/ae36.cfm

Answer 2

When we talk air passes out from our lungs through our vocal chords and is caused to vibrate and you hear the words. When you mix helium with air the resulting mix is less dense so as you breathe out the timbre of your voice is altered. The spped of sound in a less dense helium/air mix is higher than in just air. You are increasing the speed of sound of your voice when breathing out this less dense mixture and this increase in speed will affect the frequencies that make up your 'voice'.
If the frequencies are affected the timbre is affected too. A more dense gas may have a very wierd affect.
Strictly speaking although most people say it is the pitch that changes, it is the actually the 'timbre' which is changed, as your vocal chords produce the same shapes and therefore the same pitch.

Answer 3

Because sound is really just waves in the air (like 3-dimensional waves in the ocean), it can travel faster or slower depending upon the density of the medium (stuff) through which it travels.

As we all know from helium balloons, which rise when you let them go, helium is much less dense than air. So, if you fill your lungs with helium, and then try to speak, your vocal chords will vibrate at the same rate, but the vibrations (sound waves) will travel away from your vocal chords much faster than in air, increasing the frequency of the waves (i.e. if the waves move faster, you will encounter more waves in the same time than if they were moving more slowly: you will encounter them more frequently).

Since our ears perceive higher frequencies as higher pitches, speaking through helium raises the pitch of your voice, even though your vocal chords feel like they're making the same sounds they usually do.

Answer 4

Helium is less dense than air (Not quite that same as lighter).
This allows your vocal chords to vibrate faster as they are less damped. A musical instrument would also change pitch in a similar way.

Answer 5

(apparently!) if you breathe Xenon, it has the opposite effect.

It's down to the density of the gas!

Answer 6

I dont know, i think it could be the Devils work!

Answer 7

shrinks your vocal chords