Originally Posted by Burning Down

Babies also react to musical tones, and that stretches all the way back to when they are in utero. A couple of years ago, I was assisting with a longitudinal research project in music psychology, where we studied how fetuses interpret musical tones and songs. We had 20 pregnant women in the study, and at 5 months along we did the first test by playing Twinkle Twinkle Little Star and asking the women to note movement of the fetus - they all moved when the music played and stopped when the music was off. Then at 8 months, the women came back for the same test and most reported more movement of the fetus. At that point in pregnancy, the fetus can hear more sounds and can also feel sound vibrations.

Then we waited until all the babies were born, and at 3 months of age 19 of them came back (one woman had unfortunately learned that her baby was completely deaf. She moved in the womb only because she could feel the vibrations). So we played the same version of Twinkle Twinkle again, but this time with an altered note. The babies were happy and laughing until the wrong note - all the babies just froze up with a confused look, and one actually cried a bit, lol. By that age, babies are capable of a basic interpretation of the sounds around them, based on what they heard while in the uterus. So that's why they were all confused by the wrong note.