The things that go in one ear and out the other do not hurt as much as the things that go in one ear, get all mixed up, and then slip out of the mouth. (Googlebooks)
No matter how shocking they are, statistics will just go in one ear and out the other. (Google)
Just let the gossip go in one ear and out the other. In the event that you hear some alarming news that involves you in any way, shape or form; take it up with your boss or HR immediately. (Google)