I wrote yesterday's post without thinking through the known facts about prenatal hearing. I was concerned, rather, with the assumption of many young parents that their baby has not heard anything yet.
Heartbeats, breathing, digestion, all those sounds of life must have been intensely magnified in that environment, not to mention the music that the mother listened ot, perhaps even danced to, while pregnant.
It is adult assumptions that are off, not the infant's hearing.