Lately I found a good article, "The sound makes the experience," which approaches this problem from both cultural and technical aspects. It describes the reason to make noise as a very polite gesture to acknowledge cook how much you enjoy your meal. And then it describes the technique as follows:
For me, the best way to conceive of the proper slurping technique is like when you are eating a very hot slice of pizza. You take a small bite, and because it's hot, you start to suck in air while chewing. This allows you to eat the food while it is still very hot, while you are breathing in. This is the same manner in which you should eat soba in Japan.This helped me a lot. For Japanese like me, it is very difficult to teach this kind of basic skills because we all acquire them during our childhood and do not remember how we learned. Even worse, We can't understand why they can't do it.
This leads me to a conclusion that Japanized foreigners are better teachers than Japanese ourselves. I'll catch up those foreign media to learn how I should teach Japanese culture.
