According to the landlord's explanation, it's not called vibrato, it should be called air vibrato. In all wind instruments, not only the flute, but also the vibrato is very important, especially the slow, lyrical and singing music. This technique is particularly important, and its function is the same as that of kneading strings in stringed instruments. When practicing, you can consciously contract the abdomen, let the air flow alternate, and make the sound vibrate and sing like a string. Pay attention to playing.