1. ## Why Is Helium Make Your Voice High-Pitched?

I saw this State Farm commercial where there were a car accident and a gas of helium was release in an octane truck. And everybody what talking high-pitched. So my question is why is helium make your voice high-pitched?

2. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Bartmanhomer
I saw this State Farm commercial where there were a car accident and a gas of helium was release in an octane truck. And everybody what talking high-pitched. So my question is why is helium make your voice high-pitched?
Helium is lighter than air (you get the opposite effect with denser substances). Because of that sound travels faster through it, and it's to do with that.

I think it goes...

The same pitched sound in helium has a longer wavelength than the wavelength in air. A sound with the same wavelength has a higher frequency (or pitch).
This is because speed=wavelength*frequency.

When the waves are being formed they are formed at a given wavelength, which (as above) corresponds to a higher frequency.
At the helium/air boundaries the frequencies stay the same (because the point on the boundary has to be in both camps) and the wavelength changes (and it remains the higher frequency).

3. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by jayem
Helium is lighter than air (you get the opposite effect with denser substances). Because of that sound travels faster through it, and it's to do with that.

I think it goes...

The same pitched sound in helium has a longer wavelength than the wavelength in air. A sound with the same wavelength has a higher frequency (or pitch).
This is because of speed=wavelength*frequency.

When the waves are being formed they are formed at a given wavelength, which (as above) corresponds to a higher frequency.
At the helium/air boundaries, the frequencies stay the same (because the point on the boundary has to be in both camps) and the wavelength changes (and it remains the higher frequency).
Interesting. Thank you for the info.

4. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Bartmanhomer
Interesting. Thank you for the info.
You can see some more stuff here (which shows I wasn't quite right)
http://www.animations.physics.unsw.e...jw/speech.html

5. ## Re: Why Is Helium Make Your Voice High-Pitched?

First, that commercial is not serious. You can suffocate in a pure helium environment.

Now for why; well when I asked Google, the first results said;

When you inhale helium, you're changing the type of gas molecules in your vocal tract and increasing the speed of the sound of your voice. Some people think that helium changes the pitch of your voice, but the vibration frequency of the vocal cords doesn't change along with the type of gas molecules that surround them.
http://mentalfloss.com/article/21590...ce-sound-funny

6. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by LordEntrails
First, that commercial is not serious. You can suffocate in a pure helium environment.

Now for why; well when I asked Google, the first results said;

http://mentalfloss.com/article/21590...ce-sound-funny
I know the commercial wasn't that serious. It was funny. LOL! :bigrrin: Also thank you both for the information.

7. ## Re: Why Is Helium Make Your Voice High-Pitched?

Mythbusters did a nice bit with both helium and sulfur hexaflouride in one episode (so a light and a heavy gas). You can see it here.

8. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by tomandtish
Mythbusters did a nice bit with both helium and sulfur hexaflouride in one episode (so a light and a heavy gas). You can see it here.
Wow. Thanks for the video.

9. ## Re: Why Is Helium Make Your Voice High-Pitched?

As long as they stayed close to the ground and the helium was only a leak, not a full release, they'd most likely have a little bit of time to breathe safely without suffocating. You can breathe helium in small dosages, but in between huffs you should breathe normally to replenish your oxygen levels. They'd need to leave soon, though, since the oxygen levels in there would get pretty low fairly quickly.

As for why it make your voice sound higher, "When you inhale helium, you're changing the type of gas molecules in your vocal tract and increasing the speed of the sound of your voice. Some people think that helium changes the pitch of your voice, but the vibration frequency of the vocal cords doesn't change along with the type of gas molecules that surround them." (From google and my basic understanding of physics)
http://mentalfloss.com/article/21590...ce-sound-funny

10. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by TrashTrash
As long as they stayed close to the ground and the helium was only a leak, not a full release, they'd most likely have a little bit of time to breathe safely without suffocating. You can breathe helium in small dosages, but in between huffs you should breathe normally to replenish your oxygen levels. They'd need to leave soon, though, since the oxygen levels in there would get pretty low fairly quickly.
Except you wouldn't be able to tell if the oxygen levels were too low until you passed out, since the inhalation trigger in the body works off carbon dioxide concentration in the blood.

11. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Brother Oni
Except you wouldn't be able to tell if the oxygen levels were too low until you passed out, since the inhalation trigger in the body works off carbon dioxide concentration in the blood.
Which would still be going up if you were breathing helium, surely?

12. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by factotum
Which would still be going up if you were breathing helium, surely?
Actually no and this lack of detectability is is what makes inert gas asphyxiation so deadly.

During normal breathing, CO2 goes from your bloodstream to the air via the alveoli in your lungs. The primary mechanism for this is diffusion - the CO2 content in the air in your lungs is less than the CO2 content in your blood.

If you're inhaling an inert gas, the CO2 content in the gas is still less than the CO2 content in your blood, so you exhale CO2 plus the inert gas (helium in this case). However you're not taking on any oxygen, so the oxygen content of your blood stream drops and you fall unconscious.
This is in contrast to environments with high CO2 levels where CO2 is pushed into your bloodstream via diffusion along the concentration gradient, which we've evolved to detect - it's one of the quirks of evolution that we often develop a 'just good enough' response to environmental factors.

Since we're far more likely to encounter low oxygen environments in conjunction with high CO2 levels, we're built to detect that; the primary detection mechanisms is more acidic blood pH from the increased levels of dissolved CO2. This triggers the hypercapnia alarm response, which induces pain, panic and inhalation.

I've worked in several places which handle large quantities of liquid nitrogen (on the order of thousands of litres) and I've always been told if you see the low O2 alarm go off, RUN.

13. ## Re: Why Is Helium Make Your Voice High-Pitched?

Ah, OK, that makes sense. Thanks!

14. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Brother Oni
I've worked in several places which handle large quantities of liquid nitrogen (on the order of thousands of litres) and I've always been told if you see the low O2 alarm go off, RUN.
Stupid question, why would they make the alarm visual and not audible (or both)?

15. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by tomandtish
Mythbusters did a nice bit with both helium and sulfur hexaflouride in one episode (so a light and a heavy gas). You can see it here.
I can do you one better. Every noble gas lighter than Radon.

16. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Peelee
Stupid question, why would they make the alarm visual and not audible (or both)?
GMP manufacturing environment, so PPE is mandatory before even entering the facility. In busy/loud kit areas, ear defenders are also mandatory, which you have to put in before getting cleaned and gowned up. Depending on the activity and drug, full hood respirators may also be required, so if you're fully kitted up, you're not hearing much at all:

Spoiler: The height of scientist fashion

That said, there is probably an audible component as well, but the alarm's never gone off when I was working, so I can't confirm it.

17. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Brother Oni

Spoiler: The height of scientist fashion
Now remember everybody, goggles might make you look cool, but they are also a part of proper safety attire.

18. ## Re: Why Is Helium Make Your Voice High-Pitched?

There are also gases that can make your voice super low because they're heavier than air. I believe hydrogen has the same effect voice wise as helium, but I wouldn't recommend experimenting with that gas unless you know you're fire proof.

19. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Magic_Hat
There are also gases that can make your voice super low because they're heavier than air. I believe hydrogen has the same effect voice wise as helium, but I wouldn't recommend experimenting with that gas unless you know you're fire proof.
Hydrogen would actually be significantly higher pitched than Helium, though you'd need a non oxygenated atmosphere to avoid the part where everything explodes. It basically all comes down to molecular weight, and the average molecular weight of air is 29ish.

20. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Knaight
Hydrogen would actually be significantly higher pitched than Helium, though you'd need a non oxygenated atmosphere to avoid the part where everything explodes. It basically all comes down to molecular weight, and the average molecular weight of air is 29ish.
So, pure hydrogen and no matches?

Isn't hydrogen somewhat reactive anyway? it's a metal as I recall, does it do nasty things in water?

21. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Knaight
I can do you one better. Every noble gas lighter than Radon.
Now that I think about it, there is an additional danger concerning heavier gases in that they will be more dificult to breath out when you are standing. Unless you spend longer time breathing heavily or change your orientation, they might linger on the bottom of your lungs for quite a while.

22. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Knaight
It basically all comes down to molecular weight, and the average molecular weight of air is 29ish.
Never thought about it before, but that means a pure oxygen environment would drop your voice a bit, wouldn't it?

23. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Peelee
Never thought about it before, but that means a pure oxygen environment would drop your voice a bit, wouldn't it?
Yes. Then you would die from oxygen poisoning (probably, the conditions for spontaneous combustion are an open question).

24. ## Re: Why Is Helium Make Your Voice High-Pitched?

If you replaced all the nitrogen of the atmosphere by helium, would it be both survivable and hilarious?

Oxygen concentration is left untouched

25. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Cikomyr
If you replaced all the nitrogen of the atmosphere by helium, would it be both survivable and hilarious?

Oxygen concentration is left untouched
At a guess, that'd be a good way to knock the oxygen concentration up a ton. Also thin out the atmosphere significantly.

I now await being told I'm wrong by a chemist or physicist.

26. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Cikomyr
If you replaced all the nitrogen of the atmosphere by helium, would it be both survivable and hilarious?

Oxygen concentration is left untouched
In a confined environment that might work. I remember (I think) that at one point they used helium and oxygen for diving. In an unconfined space, they would tend to seperate out, the oxygen low the helium high.

27. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Knaight
Yes. Then you would die from oxygen poisoning (probably, the conditions for spontaneous combustion are an open question).
Not at regular atmospheric pressure, you wouldn't--oxygen toxicity doesn't really start to get going until you get your partial pressure of oxygen up to about 1.6 atmospheres.

28. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by halfeye
So, pure hydrogen and no matches?

Isn't hydrogen somewhat reactive anyway? it's a metal as I recall, does it do nasty things in water?
Hydrogen is not a metal and does nothing special in water. Maybe you remember hydrogen embrittlement, where hydrogen atoms diffuse into metal and reduce its toughness?

Now that I think about it, there is an additional danger concerning heavier gases in that they will be more dificult to breath out when you are standing. Unless you spend longer time breathing heavily or change your orientation, they might linger on the bottom of your lungs for quite a while.
I remember some science show for kids where they showed the effect of both helium and a heavy gas on the voice. The guy had to do a handstand at the end to make sure he got all the heavy stuff out. Cannot remember what gas it was, though.

29. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by Iruka
I remember some science show for kids where they showed the effect of both helium and a heavy gas on the voice. The guy had to do a handstand at the end to make sure he got all the heavy stuff out. Cannot remember what gass it was, though.
Very likely the sulfur hexafluoride. This gas is a pretty popular choice for science shows, since it is dense enough that you can make little boats float on it as if on water. It is also pretty inert chemically to the point that it is used for medical purposes.

30. ## Re: Why Is Helium Make Your Voice High-Pitched?

Originally Posted by halfeye
In a confined environment that might work. I remember (I think) that at one point they used helium and oxygen for diving. In an unconfined space, they would tend to seperate out, the oxygen low the helium high.
Yeah, its Trimix if you replace some of the nitrogen with helium, and Heliox if you replace all the nitrogen. It has advantages in SOME deep diving situations (not all). It is also a LOT more expensive.

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