>>291214796
>What is a viseme?
A viseme is any of several speech sounds that look the same, for example when lip reading. Visemes and phonemes do not share a one-to-one correspondence. Often several phonemes correspond to a single viseme, as several phonemes look the same on the face when produced.

>Also what should I do here?
you should select your blendshape that describes a given viseme.