duration is 10 min/level and effects 1 creature/level. What happens with a second cast? First spell ends?
It does not say. Though the first creature is likely to hear the Verbal component of the casting of the second spell.
From your previous thread: If the caster speaks Goblin well enough and knows enough about this group of goblins and has a good "Bluff" roll, there is no reason why the spell could not be used to "create confusion."