> You can train an infant to recognize a signal (a sound, a light for instance) and associate it with a pleasant or unpleasant experience.
And pre-birth, baby cries have distinct accents: https://www.scientificamerican.com/podcast/episode/babies-al...
But there’s more than one type of memory, and learned associations are not the same as episodic memory.
The reason we don't have memories from our first months of life is because, it seems, when we learn to speak the previous experiences become somehow inaccessible to our cognition (but they're still there).
It doesn't seem impossible that people who learn to speak early have more early memories.
But of course, there is always the possibility that the memories are those of the adults who repeated them so frequently that the children began to treat them as their own.