Your baby can hear you --- even from inside your womb. From the sound of your voice, the gurgles of your digestion and your gasps of air to thunder, barking dogs and other loud, startling noises in your home, your baby can make sense of a lot of the outside world. Although some of the noise of is muffled by amniotic fluid, you should exercise as much caution as possible if you work or are frequently in a loud environment. The doctor will check your baby's hearing when she is born. However, you should play soothing music and sing to your developing baby. Your baby will remember the tune.
Hearing in Fetal Development
The bones and tissue that make up your baby's ears are in place by the 16th week of gestation. By 24 weeks, they're complete. Around this time, babies in utero can blink and be startled by stimulation. Perception of sound matures as your baby develops. Your baby will go from being startled by noise to be stimulated by them. Eventually he will be able to recognize and distinguish some of them. In addition, the volume of the sound required for your baby to hear and respond gets progressively lower until 42 weeks, when his hearing will be as keen as an adult's.
NOISES STARTLE AND SOOTHE
At some point during your second trimester, you'll begin to notice your baby's reacting to certain noises. When a familiar voice comes around, like Dad's or Grandma's, she may poke or kick, an indication she recognizes the voice. According to Dr. Sears, your baby may jump at the sudden onset of sound, so if you drop a pot or go to a concert, your baby should react at this stage of development. From six months onward, your baby's sense of awareness of the world outside the womb grows exponentially. This is because her brain cortex is developed enough for thinking. Dr. Sears says your baby has a discriminating ear at this point; she may kick violently in response to loud, thumping rock music but may be calmed by smooth, classical tunes.
Babies Make Sense of Noises
Dr. Sears says that not only can developing babies identify and respond to them, noises can be use used to teach your baby when to kick. The AskDrSears.com website cites research in which vibrators were placed on mothers' belly following a noise. The babies learned to kick in response to only the vibration. In other words, they learned to associate the noise with the sensation. In addition, researchers reporting in the September 1994 issue of "Archives of Disease in Childhood," your baby's growing sensitivity to sounds as he matures may promote language development later on.
Caution
Dr. Gerard M. DiLeo, an obstetrician and gynecologist writing on Babyzone.com, says most babies, even those exposed to Mardi Gras while in the womb, usually don't develop hearing problems as a result of being exposed to loud noises. However, he says, you should err on the side of caution and avoid prolonged exposure to loud noises. When your job demands it, your baby should be checked for noise-induced hearing loss. Sometimes, the hearing problems could develop later in childhood and repeated exposure to loud noise can affect your baby in other ways. According to the American Academy of Pediatrics, children who couldn't hear high frequencies between the ages of 4 and 10 have been reported; they were more likely to have been born to women who worked in places with loud noise. In addition, the academy reports some evidence that such exposure may be related to congenital anomalies, increased risk of pre-term delivery and low birth weight