Hearing in first few days after birth

Unlike the infant's eye's which need a few months for full development, a newborn’s hearing apparatus is fully developed at birth. In fact, there is ample evidence that before birth the baby is using her hearing and reacting to outside sounds; she may move actively during a concert, or "jump" in response to the bang of a door. After birth the sound she hears is more amplified of course, but the womb is not an altogether silent place; sounds from the mother's organs reach the baby.

Hearing within a month

A constant sound for the unborn baby is the mother's heartbeat. This may explain why the newborn baby is often soothed by soft rhythmic sounds. Do they re-create the tranquility of her uterine home? She will often become very calm listening to the tick of a clock, the singsong thrumming of a music box, or the age-old soother, a lullaby combined with rocking. And the hum of a car in motion is well known to experienced parents for its almost miraculous calming effect on a nervous and complaining baby. It is interesting, too, that almost all parents, whether right or left-handed, hold their baby on the left side of the body where she can hear the adult's heartbeat. Either instinct or a few hours of experience seems to clue in the parent to the baby's preference for this holding position.

Human voice - what it means to babies

A baby has preference for human voice and this is demonstrated quite well during the first month. Why human voice is so special is still not clear but it is special nonetheless. The affinity may be because of time spent in the womb and the human voices heard during that time. This is evident when you speak to your baby especially in a high-pitched tone, the baby will turn her head and search for you and will carefully keep looking at you as speak out distinct syllables. It is also observed that babies are sensitive to loud noises. If you suddenly slam the door or take her in a crowded and noisy room, the baby will either shut-out as if she did not hear anything or she may begin crying displaying her uneasiness.

Sound preferences

Even when the baby is nursing or sucking on a pacifier she will inhibit her sucking to listen to a new sound, then after "taking it in" will resume her sucking. Babies become accustomed to most of the normal sounds in their household and so cease to react to them. It is seldom necessary to shush brothers and sisters (Don't wake the baby!") unless they're overly rambunctious.

At one month, not only do babies hear well, they also remember sounds. If you sing a lullaby or repeat certain names again and again, the baby will remember the sound and will respond appropriately next time she hears it.