Did you know that infants prefer their mothers' voices to that of other females? And that they will change their behavior in order to solicit her voice?
A fetus can also distinguish its mother's voice from that of other females before it is even born?
Scientists discovered this byÂ listening to the fetuses' hearts. Fetuses at term were played recordings of their mothers reading a poem, as well as recordings of a female stranger reading the same poem. The fetuses' hearts accelerated when they heard their own mothers' voices, but actually decelerated when they heard the voice of the female stranger. The recordings lasted two minutes, but the effects on the fetuses' hearts went on for several minutes beyond the recordings.
That experience in the womb seems to affect newborn preferences and behavior. Not only that, but fetuses' recognition of their mothers' voices proves that fetuses are capable of learning. This all leads scientists to believe that the process of learning language may begin before birth. Perhaps that infants are so quick to pick up on language shouldn't be surprising. They've had some experience with language before they were born. In fact, their speedy grasping of language may not be due to some innate ability hardwired into the brain. It may be due instead to information the fetus began accumulating in-utero.
"Fetus Heart Races When Mom Reads Poetry; New Findings Reveal Fetuses Recognize Mother's Voice In-utero" (Science Daily)