"I'm pregnant and have tickets to a rock concert, but I'm concerned about my baby's safety. Can loud music harm his hearing? Is there any danger to listening to loud music in my car?"

A night on the town with friends can be a great way to kick up your heels before your evenings become booked solid with baby duties. But will booming bass and screaming vocals be bad for your baby in utero?

Probably not. At almost all concerts, the music isn't loud enough and doesn't last long enough to cause any damage to a fetus. Still, you might want to take a few precautions.

Babies begin detecting limited noises around week 16 of pregnancy. At about 24 weeks, your baby's outer, middle and inner ear — including the cochlea, the snail-shell-shaped tube in the inner ear where vibrations are converted into the nerve impulses we perceive as sound — are well-developed, and baby's ear is mature enough that he will likely turn his head in response to voices and noises.

The sounds inside your uterus, of course, are muffled — and not just by the physical barrier of amniotic fluid and your own body. In his fluid-filled home, a baby's eardrum and middle ear can't do their normal job of amplifying sounds. So even sounds that are quite loud to you won't be to your baby.

Of course, that's only true as long as the sounds aren't excessive and don't last too long. What experts are particularly concerned about is prolonged and repeated exposure to very loud noise from, say, an eight-hour-a-day shift in an industrial workplace. The National Institute for Occupational Safety and Health advises that pregnant women avoid routine exposure to noise louder than 115 decibels (think of the noise a chainsaw makes). Studies indicate that regularly experiencing that level of noise raises the odds of a baby suffering some hearing loss, especially at higher frequencies. Repeated exposure to very loud noise can also increase the risk of premature delivery and low-birth-weight babies.

Frequent brief exposure to extremely intense sound, at 150 or 155 decibels (ever stand right next to a screaming jet engine?), can cause similar problems for fetuses. But you'd have to sit in front row seats, next to the amps — and be at a really loud concert — to get close to that intensity (you'll know because your own hearing will be fried).

Still, it's not a bad idea to play it extra safe during your pregnancy. So position yourself toward the back of the concert hall, away from the speakers. You'll enjoy the music just as much — and you'll be certain your baby's ears are safe. As for music in your car, if you drive often and like your radio loud enough to shake other cars, you might want to turn it down a bit.

Have fun,
Heidi Murkoff