> I have doubts that every phoneme of every world language can be discriminated by adults after the early-childhood language acquisition Based on my own experi

> I have doubts that every phoneme of every world language can be discriminated by adults after the early-childhood language acquisition Based on my own experience of emigrating to a country using a different language than my native tongue, I think it can be done over time, but my understanding is that we use a different part of the brain for languages learned late in life.