The phrase "lifted a voice" indicates someone raising their voice to speak out or make a statement. Antonyms for this phrase might include "stayed silent," "soft-spoken," "mumbled," or "whispered." These terms describe someone who chooses not to speak up, or who speaks in a quiet, subdued manner. Other antonyms might include "repressed," "suppressed," or "kept to oneself," indicating that the person is actively holding back their words or feelings. Whatever the antonym used, it represents an opposite action to the act of raising one's voice, which can convey a sense of power, authority, or urgency.