You know all those loud noises you ignore, like a plane overhead or a truck hitting a pothole? Don't be surprised if they freak out your baby big-time, at least for a while. Yep, that same wee person who stares out at the world and sees a blur, and who's happy to drink breast milk or formula for every meal without begging for variety, does have one finely developed sense from birth: his hearing. "Even in newborns, it's at the same level as an adult's," says Diane Sabo, Ph.D., director of audiology and speech-language pathology at Children's Hospital of Pittsburgh.
a scary earful. But though your baby hears as well as you do, he doesn't yet have an adult's (or older kid's) vast mental catalog of sounds. So while you may shrug off, say, the din of applause because you can instantly ID it, "It doesn't mean anything to your baby-it's just loud," Sabo says. "And the only way he can show he hears it is by doing something physical, like raising his arms." Or, of course, crying.
soothing moves. Pick him up and say, "That was loud! But it's okay," and tell him what made the sound (if you know). If your baby is extra sensitive, help him acclimate by gradually increasing the background noise around your house -- play the radio softly for a few weeks, then try it a little louder. By age 2, your child will probably have enough life experience to handle many noises calmly (though we can't promise he'll adore his great-aunt who laughs like a hyena -- do you?).