Babies typically like to listen to classical music and lullabies.
Babies are usually born with their auditory systems fully wired up, and they're more sensitive than adults, so anything louder can hurt them.
Furthermore, due to the high-fat composition of a fetal brain, stimuli that it may not react strongly to in later life (such as noise) may produce considerable overstimulation in utero.
The degree of this overstimulation depends on how stimulating the stimulus is on top of being louder.
Some people find soothing sounds will act as white noise for infants when they sleep in an unfamiliar place or environment, but without those calming noises babies might feel frightened if their sense of hearing is keener than ours.