I've had many discussions about this topic with other people before and my opinion for slurping while eating Soba noodles is to bring out the aromas, just like when you do wine tasting.
Some people told me that it is also to give compliments to the chefs, but I couldn't quite agree with it.
That is true- Japanese people are well known for their politeness and humbleness.
While there are so many taboos for using chopsticks and other things, why do we "slurp" that is a taboo of western culture? It is OK only when you eat noodles and soups, not while chewing.
There should be a better reason than just "to give compliments to the chef". I still quite like my theory of Soba though, it does not apply to Udon, Ramen and soup.
So I searched:
There is a functional reason- As Japanese people eat soup and noodles while they are with how they eat that ends up making some sound, it bring down its temperature.
More importantly, It is not about you should "slurp" or not "slurp". Japanese have a culture of "enjoying the sound" while eating as well as tasting on your tongue, smelling the aromas with your nose and watching with your eyes. Japanese culture is not black- and- white. It is full of ambiguity, just like Japanese colors. This can also be said in Japanese words, attitude, philosophies, and our sense.
This is the theory that I found and I could agree with.
I'm not sure what you think from this.
"Eating does not consist of only manners and taboos."
If you have this in your mind, slurping sounds that a Japanese person making next to you while eating noodles may become a little less unbearable?