What Can My Baby Hear?
Hearing is fully developed at birth -- in fact, your baby was hearing sounds even before she was born. Newborns may startle when they hear a loud noise, or quiet down when they hear soothing sounds or white noise -- such as the sound of a fan -- that reminds them of what they heard in the womb.
Amazingly, babies will recognize their mother's voice even in the first few days of life. But they can't localize a sound or turn their head in that direction until about 3 to 4 months of age.
When and How Is My Child's Hearing Checked?
Most states have mandated universal hearing screening for all newborns, which will identify most serious hearing defects at birth. But because hearing loss can occur at any age, your pediatrician will still be monitoring your baby's hearing at each visit. For example, when a baby is 3 to 4 months, your pediatrician will use a bell or beeper, or just clap her hands, to see if he turns toward the sound. And that's when baby talk comes in handy, as your doctor observes how your child mimics the sounds she makes. Once your baby is 6 months, your pediatrician will follow language development.
Besides checking hearing at office visits, she'll order objective auditory exams if your baby has middle-ear fluid for three months or longer or chronic ear infections, or after he's had a serious infection that can lead to deafness, such as meningitis. Then baby might be tested using auditory brainstem response (electrodes are placed on the head to measure how sound -- transmitted through soft earphones -- is transferred from the inner ear to the brain). Conventional audiometry (a patient raises his left or right hand when a sound is heard in that respective ear) may be used, particularly if your child is older. At home, you can indirectly monitor your baby's hearing by observing his language development. First he'll coo, squeal, and babble. Then by age 1, he should be able to say one or two simple words. If you suspect he's not reacting normally to sounds, call his doctor.
Aside from newborn hearing screening, the American Academy of Pediatrics recommends periodic objective hearing screenings by pediatricians using conventional audiometry, beginning at age 4. At this age, kids are better able to cooperate because they can understand the directions they're told.
How Can I Use Sound to Get Her to Talk?
That high-pitched voice we all use instinctively when we speak to babies is just what they react to the most in those first weeks. But don't stop there. Talking to your baby is the single most important thing you can do to help her acquire language skills during the first two years. A baby's ears are tuned in to different sounds, and over time your baby will learn which sounds are more essential than others -- this is how speech develops. Babies also love music, which stimulates them and has a calming effect. Watching how your baby reacts to music is another fun way to tell if she is hearing well.
My number-one rule when it comes to questions about a baby's vision or hearing: trust her parents. Often they're the first to notice sensory problems with their infant. Working together is the best way to keep babies seeing and hearing the world around them. So, for instance, when you see your baby reaching for and grabbing objects -- signs of hand-eye coordination -- be a proud parent and tell your pediatrician at the next well-baby visit. These details provide a wealth of information. In this case, they tell the doctor about your baby's fine motor developments and her vision. Between office visits, smile, laugh, sing, and expose your baby to a world of sights and sounds.