Final answer:
The repeated knocking in the stage directions amplifies tension and unease, symbolizing the inescapable consequences of Macbeth's actions.
Step-by-step explanation:
The repeated knocking in the stage directions primarily makes the characters, particularly Macbeth, uneasy. This inclusion in the scene signifies increased tension and a foreboding sense that something is amiss. Macbeth, having just murdered King Duncan, is in a state of heightened paranoia and guilt, evident through his lines where every noise causes him alarm and he wishes the knocking could awaken Duncan. The knock serves as a physical reminder of the outside world and a moral reckoning for Macbeth, signifying the inescapable consequences of his actions. It drives home the theme that one cannot easily disconnect from their deeds.