The answer "He sleeps and does not listen" should definitely be accepted., but there is a problem with this sentence. It has been deleted from the course, but obviously it still appears. This means we can't edit it and add new translations. I reported it to Duo yesterday, but I have no idea how soon it can be fixed.

The ghost sentence thing hasn't been solved, and I don't think it will be before the holidays are over.
He doesn't sleep or listen, I'd prefer Han varken sover eller lyssnar (lit. He neither sleeps nor listens).