It is normal for babies to actually hear while they are still inside mother’s womb. Their hearing is so sharp that they can distinguish among different variety of phonemes when they are only 2 month old. However, it narrows down to their native language at about 6 to 8 months, which is exactly a time when they start trying out to make their first sounds.
The basic anatomical structure for vision is always present. The first vision is blurry, they only see what is right in-front of her face. However with age progression it changes. Between 2 and 3 months of age, they can coordinate their vision with both of their eyes. Thus when they reach 7 and/or 8 months of age their visual senses are good as adults, making it easier for them to crawl.
Also the color perception for babies improves by the time they are 2 months old, along with color they start sensing boundaries to most of the things they see.
Taste and Smell
Babies have main three senses of taste that is overly-developed are sweet, bitter and sour. Their facial expression are reflexive yet similar to adults.
However, they can smell and sense sweetness very well, that is how they can find their mother’s breast-milk for their nourishments.
That is why mother’s diet during pregnancy is also important. The food which mother consumes in large quantities, would be a food of choice for the baby; so Mom’s choose wisely.
By putting the babies sense of taste and smell, and vision. It should be simple to understand how babies, by the time they reach their 3 months, they prefer their mother’s face, her voice, and even her smell to any female stranger. But this would be for a different subject, to follow.