In literature, "mutter" is often used to convey speech that is soft, indistinct, and laden with unspoken emotion. It frequently appears when characters express reluctance, anxiety, or irritation, speaking under their breath in a way that suggests hidden depths of feeling, as when a character mumbles incoherently in stress or uncertainty [1, 2]. Authors also employ the term to capture moments of subtle disdain or secretive commentary—indicating that the character’s words, though barely audible, are loaded with meaning [3, 4]. Beyond dialogue, "mutter" can evoke the ambient, almost elemental sounds of an atmosphere fraught with tension or melancholy, thereby enriching the narrative’s overall mood and inviting readers to sense the undercurrents of emotion that lie beneath the surface [5, 6, 7].