In Harry Potter and the Deathly Hallows Ron enters into the the 'Chamber of Secrets' by mimicking parseltongue. How exactly could he enter into Chamber when he is not the one. Does the magic on doors not recognize whether the person is really s parseltongue or not?
What is certain is that by the time Slytherin was forced out of the school by the other three founders, he had decided that henceforth, the Chamber he had built would be the lair of a monster that he alone – or his descendants – would be able to control: a Basilisk. Moreover, only a Parselmouth would be able to enter the Chamber