Each year, approximately 1 in 300 babies is born with a degree of hearing impairment. About 4,000 of these children are considered profoundly deaf, making hearing loss the most common birth defect in America, according to the AAP.
For these children, timing is everything. The earlier a hearing loss is detected, the more likely it is that interventions such as hearing aids, cochlear implants, and speech therapy will help that child build speech and language skills and be mainstreamed into regular education classrooms. "Cochlear implants and hearing aids can be fitted for babies as young as 6 months old," says J. Thomas Roland Jr., MD, codirector of the Cochlear Implant Center at New York University Medical Center.
The first three years of life usher in the busiest period of language development, with the early months being the most critical. In fact, baby's sense of hearing is fully developed at birth. By about the sixth month of pregnancy, your unborn baby is able to hear sounds, and after he's born, he will recognize his mother's voice. He may even seem to recall a song or other sounds he heard before birth.
Your newborn will react to a loud sound by startling -- jerking his arms and hands outward. And he'll respond by quieting down when you speak to him. Talk, sing, and coo to your baby, who craves the sound of your voice. Babies are most attracted to human voices, and they prefer high-pitched ones like Mom's. Use baby rattles and music to stimulate hearing, and expose her to everyday sounds such as cooking noises, vacuuming, and the sound of older siblings at play. By 6 to 7 months, your baby should begin babbling -- repeating simple sounds like "ga" or "da."
As she gets older, your baby will get better at tracking where sounds come from. In the first few months, she'll only look for a sound when it originates in front of her. By 3 months, she'll turn to a sound on her right or left side. Later she'll be able to look for a sound coming from behind her.
If your baby is not responding to sounds or not developing age-appropriate language skills, there may be a problem. Remember that every child is different and will reach milestones at his own pace. Nevertheless, consult with your pediatrician about any concerns, especially if your newborn wasn't screened for hearing loss at birth. Don't delay: One study from the University of Colorado found that children whose hearing losses were detected by 6 months of age had normal language skills when tested at age 3 compared to children identified later, who were behind.
Risk factors for hearing loss include family history and premature birth. Your child is also at risk if you had a virus such as measles, mumps, or rubella, or infection with toxoplasmosis, syphilis, or herpes during pregnancy. After birth, bacterial or viral meningitis and frequent and untreated ear infections can also raise your child's odds of a hearing problem.
About half of all cases of hearing loss are genetic in nature, with recessive genes largely to blame, says Cliff Megerian, MD, director of otology and neuro-otologic surgery at Rainbow Babies & Children's Hospital in Cleveland. That means Mom and Dad may have normal hearing, but if they both carry a recessive gene that causes hearing loss, their children could be born hearing impaired.