Ng's point is that babies don't need to be explicitly taught the concept of phonemes. They learn them from the intrinsic structure of the language (same with s

Ng's point is that babies don't need to be explicitly taught the concept of phonemes. They learn them from the intrinsic structure of the language (same with syntax). Training with text is roughly analogous with pointing at things and saying what they are called. While the concept of phonemes is certainly valid, the specific mappings created by linguists could be considered ad hoc. E.g. English has a huge number of pure vowels. Maybe there is some order order to English vowels them that is hard to capture in the representations linguists use, but easy in these models.