You can describe someone's voice or words as honeyed when they are very pleasant to listen to, especially if you want to suggest that they are insincere. 甜言蜜语的
adjective [原级]甜如蜜的;多蜜的;逢迎的;亲昵的
His gentle manner and honeyed tones reassured Andrew. 他温和的态度和甜蜜的语调消除了安德鲁的疑虑。