In what way does the bell toll not only for duncan but also fr the tragic hero?

The bell which is L. Macbeth's signal that all is clear to stab Duncan 30 times. This is also the act that will change Macbeth forever. Macbeth calls it a "knell" that will summon Duncan to "Heaven or Hell". It pretty much does the same for Macbeth. Not only does God hate it when some guy kills his King but it also sets Macbeth down his bloody road to psycho killer town.