There are multiple countries, particularly in Asia, where slurping while eating certain dishes is considered polite. For example, in China and Japan, diners who are consuming noodles or noodle soups can often be heard loudly slurping as they eat.
In these contexts, the slurping noise is seen as a sign of approval and enjoyment. A diner who does not slurp as he or she consumes a bowl of noodles is not signaling that the food is to their liking, and may therefore be seen as insulting the chef. To avoid this faux pas, travelers should listen to their fellow diners and follow their example.