We know that fetuses can hear before birth because newborns:

Question

Quizplus · Accepted Answer

Research has shown that newborns have a preference for sounds that were presented repeatedly before birth, indicating that they had heard and remembered those sounds while in the womb. This suggests that fetuses are able to hear and process sounds before birth. Aversion to loud noises is not necessarily an indication of fetal hearing, as this reflex may develop postnatally. The ability to fall asleep while hearing lullabies may be more related to the calming effect of the music rather than fetal hearing. Finally, there is no evidence to support the idea that newborns respond more to sounds that were not presented before birth.

We Know That Fetuses Can Hear Before Birth Because Newborns