We've wondered whether this is why people grow up liking roller coasters. Why people grow up liking hot chilies or spicy curries may also have something to do with the fetal environment. By 13 to 15 weeks a fetus' taste buds already look like a mature adult's, and doctors know that the amniotic fluid that surrounds it can smell strongly of curry, cumin, garlic, onion and other essences from a mother's diet. Whether or not a fetus can taste, there's little question that it can hear. A very premature baby entering the world at 24 or 25 weeks responds to the sounds around it, observes Als, so its auditory apparatus must already have been functioning in the womb.
Many pregnant women report a fetal jerk or sudden kick just after a door slams or a car backfires.
Even without such intrusions, the womb is not a silent place. Sounds include the whooshing of blood in the mother's vessels, the gurgling and rumbling of her stomach and intestines, as well as the tones of her voice filtered through tissues, bones, and fluid, and the voices of other people coming through the amniotic wall. Fifer has found that fetal heart rate slows when the mother is speaking, suggesting that the fetus not only hears and recognizes the sound, but is calmed by it. Fetal Vision Vision is the last sense to develop. Just as the womb isn't completely quiet, it isn't utterly dark, either.