This argument could go on forever, because everyone has a different definition of 'training.'

At one extreme, training could be defined as learning from a music teacher with a music degee. At the other extreme, merely hearing someone hum, whistle or sing a tune counts as training.

I learned about that second def. in a Chinese restaurant. There, members of the staff, many newly-arrived in the U.S., sang 'Happy Birthday' to a baby girl. It was awful. (It was also charming.) They knew the words, but some had never internalized the intervals in do-re-mi-fa-so-la-ti-do.

That made me realize that Westerners are all trained to duplicate certain intervals.   Even those who have never heard The Sound of Music.