8 weeks old

Your baby can tell the difference between familiar voices and other sounds, and he's becoming a better listener. He can also show you that he's in tune with his environment. Notice how he looks to see where certain noises are coming from.

An ongoing conversation (although seemingly one-sided) can help your baby develop his sense of place. He may even watch your mouth as you talk, fascinated by how it all works. You'll be amazed by his ability to communicate with a growing repertory of coos (musical, vowel-like sounds), smiles, and unique cries to express his different needs.
At this point, your baby will begin to move beyond his early preferences for bright or two-toned objects toward more detailed and complicated designs, colors, and shapes. Show your baby — and let him touch — a wider variety of objects. Good choices include plastic cookie cutters, soft balls, and stuffed animals.