i have a question: why in the iron wire hung gar form (i think thats the name), doing some chi kung practice, the performer "laugh"?

i know about some "shouts" like "hei" or "fu/hu", but i cant find the explanation about the little laugh!

It could be due to the fact that "Qi" (breath) had passed through a sensitive spot in the nerves system, causing someone to laugh involuntarily.

dont know, if it can help, i post a link to a youtube video:
http://www.youtube.com/watch?v=cqkZ_PQi6NM

also, you can see this in 36th chambers os shaolin movie (gordon liu) intro.

I believe that is a kind of breathing method during the qi movements similar to other noises he made. In the video, I feel he was more concentrated on the breathing techniques and internal qi movements than the outer physical movements. The outer physical movements were only to help the qi movements, or more precisely to let the qi movements go through parts of his body to train his physical muscles, bones, etc.

I saw something like this a couple of years ago at a Martial Arts competition (well more like a meet up, convention) in St. Louis.
The Master was an American in his 40-50s and he did a spurt of laugh, as if he was releasing bits of air.

This seems to be what the laughing clubs are all about where people gather everyday just to laugh.
I don't think they are trained to raise qi or anything like that but the basic idea of moving the qi thru the body though laughter is still there whether they know it or not.

if a person is alive, there is a qi travelling in his/her body.
every movement has some effect to qi.some are bad for it, some are good for it.
laughter is opening person's chest. so it brings more oxygen in and shall be good for qi.
that's my opinion.
qi has three level, one is 气 in Chinese, the second is 氣, the highest is 炁 .
i think laughing qigong is just good for the lowest qi.
and it's just a kind of exercise for health, not relationship with martial art and daoist.
^0^

I understand what you are saying, but I disagree.
Even if laughing produces a lesser quality of Qi the other activities. Moving and creating Qi in you body is a good and healthy for your body and soul, where as doing nothing creates stagnation.

Remember the saying
Laughter is good for ones soul.

i agree that laughter is really good for one, body and soul.
but can it cure people from dangerous sick?can it tell us what will happen about weather in next minute?
when it is called qi gong, i think it should have some character of qi gong.
that is why i have said above!
what's your opinion?

There is a technique called laughing breath in some of the internal martial arts. It is supposed to vibrate the chi into the bones. Striking with laughing breath is supposed to increase internal damage to the strikee. (The Chinese name reputedly translate laughung breath. Sorry I can't remember the Chinese).

You see it in the chi gung form some shing yi systems use, in one version of tai chi chuan, and in some external systems.

My father did learn those techniques in his youth and talked about them sometimes, but I am not really sure which style he had learned from his master. His master was very old by that time (late 80's), and he was very young (pre-teen), so I doubt he really understood which school of martial art he was learning. I did meet some of the martial art masters who practiced the same way and told me about similar techniques in their practices.

If certain basic breathing exercises are done to massage the organs. The the act of laughing must have a positive affect on them.

If we step away from the metaphysical and look at the scientific.

Laughing is proven to increase the production of endophines.

It is also a fact that depression can cause a number of illnesses as well as exacerbate others.

Raising the level of anyone's emotional state is a positive step in healing.

These are facts.

If you also accept that there is such a thing as Qi, (even if it is just another name for endorphins.)

And there is actually a way to increase it and thereby increasing the endorphins. Then yes, I think it is possible to heal.

Whether this can be proven is questionable.

I do know that there are people who seem to steal Qi and that after being around them you feel drained.

I also have experienced being around people who seem to over flow with an abundance of Qi and just being around them makes you feel better.

I personally think that if a person learns to use it and develop it properly they can heal.

If a person really gifted with the power to control his Qi, He might be able to heal himself and perhaps others.

Instantly heal? I am not sure about that, but it is not without possibility.