While in womb, babies begin learning language from their mothers. Babies only hours old are able to differentiate between sounds. You may be surprised that the basis for their language skills is laid in the womb. The baby can hear their parents speak, particularly the mother. It sounds a bit muffled, but baby hears it. They learn to recognise certain speech patterns and the voices of their parents, siblings etc.

So a little human is in a cushioned well, for almost 9 months. That little human hears sounds, voices, shares food(major portion), sleep (kind of) with one person for the entirety of those 9 months.

Then the little human comes out and with whatever little vision he has at that point, is finally able to give a face to that voice.