Final answer:
The onomatopoeia 'hums' in Macbeth creates an uneasy mood, suggesting a subtle, underlying tension reflective of the characters' disturbed state.
Step-by-step explanation:
In Act 3, Scene 6 of The Tragedy of Macbeth, the onomatopoeia of 'hums' contributes to an uneasy mood. This auditory imagery is subtle and does not evoke the violent or overtly ominous tones that would suggest aggression or horror. Instead, 'hums' may imply a continuous, underlying disquiet that permeates the scene, reflecting the tension and anxiety that the characters feel in the wake of the dark events unfolding.
It's the sort of sound that can be both mundane and foreboding, depending on the context - and in the context of Macbeth, it underscores the sense of something not being right, akin to the quiet but relentless buzz of a disturbed hive.