@Mo Cuibin Maybe the singer added some linking while singing. That's why listening this clip can hear LA, NA or EA. But when listening to the whole song, since we know “啊” is pronounced as "A", we only hear the A sound and nothing else. Here's the whole song link(around the 1:11): https://www.skool.com/lme/to-my-chinese-studentsand-anyone-actually