A child, or at least someone looking back on a frightened time, describes living on high alert around a drunken, angry man. The speaker has trained their senses to pick up the smallest warning: a footstep, a door, a shift in the sound of the house. The title says it all. Survival depends on noticing the slightest change.
The first lines capture that tense watchfulness. The phrase "swaying between seething and swinging" works on two levels, since the man's unsteady body and his unstable temper move together, and the repeated "s" sounds make the line feel like a hiss building toward violence. Anger is always a breath away from action.
The surprise comes at the end. You might expect noise to be the scary part, but the speaker says silence frightened them most. Silence offers no clues. It could mean calm, or it could mean something is about to happen. The mood is hushed, anxious, and quietly chilling.