We Japanese have soup with a spoon, but no matter what, we can't help making a slurping sound. This tendency to slurp seems to be especially true of Japanese men.
Most women tend to pay more attention to proper dining etiquette.
When I'm eating with other Japanese, I don't pay much attention to this. To be honest, I hate having soup with a spoon because I don't feel satisfied having it with a spoon. Actually, the other day, I discovered the secret to skillfully having a bowl of soup. It happened while I was eating lunch in the company cafeteria. I found myself unconsciously staring at Martha, one of our American staff members.