What is the definition of Settled Sounds?

"Settled sounds" refers to the background noises that seem to have taken up permanent residence in our ears, like the distant rumble of a sleeping bear or the constant hum of a vacuum cleaner from another room. They're the unassuming companions of our daily lives, soothing yet slightly unsettling because they're always there, never asking for anything in return.

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Here's an edgy example sentence: "The settlement sounds of the old, creaky door echoed through my mind like a sinister lullaby, promising doom and eternal silence."