How do you un-ring a bell?

Question

How do you un-ring a bell?

Answer 1

You can't - it's the law of Karma. Once you set something into motion, it has to run its full course, whether it be a word, or a sound.  

Answer 2

Gnir?

Answer 3

In Dr.Phil's words, "Once you say something, you can't un-ring that bell".