Dont you hate that noise people make when they eat crisps?!
That first bite, with their mouths open, the chewing - that seems to be louder than any other food item that you chew... and finally the constant rustling of the packet as they scramble greediliy for the final crumbs in the bottom corner!
Next thing, they will will be ripping the bag open and licking the salt/flavouring etc from the inside of the packet!!!!