I found this interesting information about infants development stages
From Ann Logsdon,
Developmental Milestones – Your Baby’s First Six Months
Baby’s Sensory Development – Responding to Sounds and Hearing: Within the first few weeks after birth, your baby will begin to respond to sounds in his environment by tracking them with his eyes and turning his head toward them. He will show recognition of familiar voices and will show enjoyment when hearing favorite songs. He will show a startle reflex when hearing unexpected, loud noises.
Crying is a baby’s first communication. His crying signals his discomfort. As we respond to his crying, the baby learns that his crying brings him what he needs. At a very basic level, he is learning that communication is a two-way process. During this period, the baby will babble and begin making delightful sing-song sounds. He is learning to control his voice and form sounds with his facial muscle structures and tongue. Mouthing objects such as teething toys helps develop muscle coordination and precision that will be needed for later speech development. Now if we don’t respond to the baby’s crying needs, the baby becomes insecure and mistrustful, if we do show love and affection to the baby then the infant well – handled, nurtured, and loved, develops trust and security and a basic optimism.
During this period, a baby is beginning to learn to communicate. As he expresses his needs by crying and gesturing. For example, he may turn his head and reach for people and objects. He may turn his head away from foods he does not like. He is learning to express himself in basic ways. He will develop clear signs of pleasure, as in happy babbling and smiles. He will show discomfort and frustration through crying. He will begin to show preferences for certain people and discomfort with others. Through these exchanges, the infant will learn to trust caregivers who meet his needs and mistrust others.
Babies love and learn from repetition, so don’t worry about doing the same things over and over. Repetition, in fact, is the best way for your baby to learn. If as adults takes us on average 20 times for us to pick up a new habit, imagine what will it take for a baby, so repetition is a key factor in the baby’s growth.
Always respond to your baby’s communication. Speak softly, sing to him, and gently touch and pat him for comfort. To calm a baby, rock him gently, hold him, and speak calming words in soft tones. Respect your baby’s need to sleep and turn away from stimulation.