Why does your voice rise when you inhale helium?
541309
Your voice raises when you inhale helium, because it is less dense than the air that you breath normally.  Since it is less dense, the speed of sound is higher, this makes the pitch rise. Air is mostly nitrogen (atomic weight 7), which is 350% heavier than helium (atomic weight 2). So, about 350% higher.
790454
Your larynx (vocal cords) are relaxed and loose, which means they vibrate slower, which results in a lower sound.\n\nWhen you are tenser, your larynx tightens, which makes the pitch of your voice go higher.\n\nPay attention when you argue with someone; their voice will go up in pitch as they get more and more stressed out.
437338
Because sound waves can travel faster through helium than oxygen because helium is a noble gas. So when you talk through helium the sound moves faster making it sound higher in pitch. If performed incorrectly it could kill you!
738177
density of helium balloon is less than density of air( with 1 atmosphere pressure) so it goes up(just like wood floating water).\nbut density of air decreases by decreasing pressure(i.e. increase altitude) so in a certain altitude, density of air becomes equal to density of balloon then balloon cease to go higher.\n\nto get more info you can search "archimedes principle"\n\nI'm afraid you can not explain that to your kid! better to buy him a new balloon !\n\nmy source : studies in university
372306
Depends on how much helium you put into it, and how big your baloon is, and how and where you release it, and... it may well heep going up and up and up to the top of our atmosphere if you put enough in.
147009
Helium alters your vocal cords (temporarily, as I'm sure you discovered), causing the pitch of your voice to arrive.\n\nWhile it can be a lot of fun, repeated exposure to your larnyx isn't good for it.
1102413
b.c ur whisper turns into loudness
762603
When the person speaks, the helium in his lungs go into his mouth and out of his mouth and into the immediate space in front of it.\n\nWhen you hear his voice, it will have gone through a substantial amount of helium before going through air :)
907929
The sound waves generated in helium gas have less momentum due to the lighter molecular weight of helium. Then when they hit the air going out to the ear, they can move those heavier nitrogen and oxygen molecules around as fast. This results in a decrease in th distance between compression waves, which then sounds like a higher pitch.
197126
This is common, and has happened to me as a vocal student before , a FEW times, when I was not supporting correctly! Always remember to speak AND sing from the diaphragm area.
613176
Hiccups are a result of spasms of the diaphragm. The diaphragm is the dome-shaped respiratory muscle seperating the chest from the abdomen. It aids in breathing by moving up and down, sending air in and out of the lungs. Find a picture to get a better idea of how this works. Hiccups are an involuntary (meaning we don't make them happen or continue to happen, they do so on their own, just like breathing and our heart beating are involuntary) rapid closing of the vocal cord that causes the sound you hear, "hiccup!" Common causes of hiccups include eating too fast, indigestion and laughing a lot, thereby inhaling and exhaling air irratically.
167
Hiccups are sudden, involuntary contractions of the diaphragm muscle. As the muscle contracts repeatedly, the opening between your vocal cords snaps shut to check the inflow of air and makes the hiccup sound. Irritation of the nerves that extend from the neck to the chest can cause hiccups.\n\nAlthough associated with a variety of ailments (some can be serious such as pneumonia or when harmful substances build up in the blood for example from kidney failure), hiccups are not serious and have no clear reason for occurring.
387542
because air builds up inside us. It happens if you eat quickly or talk fast because you aren't getting enough air or you are getting air randomly so your body doesn't have chance to use it properly. Then it gets stuck and it comes out as hiccoughs
137886
Sound travels faster through water because the particles in water are already touching each other (in gases the particles are all spread out). [the other answers have dealt with this in more detail]\n\nHelium is less dense than air becuase helium molecules weigh less than regular air molecules (a molecule of helium is two helium atoms, so its atomic weight is 2x 2 = 4. Air is mostly nitrogen, with molecular weight 2x 14 = 28).\n\nHowever, the molecules in helium are almost exactly as close together as the molcules in air. In fact, in any gas, one mole of molecules takes up the same amount of space - 24 litres at standard temperature and atmospheric pressure.\n\nSo, sound can travel faster through helium because the particles are the same distance apart as air, but they are lighter so it is easier to get them moving.
156918
Helium is an inert gas that is lighter than air and can be inhaled briefly without risk of death. Sound is produced by vibration, the movement of air around our vocal chords. Because helium gas is lighter than the usual oxygen/nitrogen blend, it changes the resonant frequency of the human vocal tract, causing a faster vibration and a higher-pitched, cartoon-character sound.
440595
The diaphragm almost always works perfectly. When you inhale, it pulls down to help pull air into the lungs. When you exhale, it pushes up to help push air out of the lungs. But sometimes the diaphragm becomes irritated. When this happens, it pulls down in a jerky way, which makes you suck air into your throat suddenly. When the air rushing in hits your voice box, you're left with a big hiccup.\n\nSome things that irritate the diaphragm are eating too quickly or too much, an irritation in the stomach or the throat, or feeling nervous or excited. Almost all cases of the hiccups last only a few minutes. Some cases of the hiccups can last for days or weeks, but this is very unusual, and it's usually a sign of another medical problem.
737720
No, in my head, I sound really cool - till I open me gob and sound like a drunken rat on helium!!!!!