I've seen earrphones shaped for kids' ears, a few that limit decibel levels, and I've told you how you can set volume limits on iPods.

AirDrives makes earphones that fit a child's ear—outside it, really—while still allowing her to hear surrounding sounds. The earphones leave the auditory canal unplugged. Still, the sound is good. An easily adjustable wire goes over the ear to help the earbud sit and fit right.

The adult version is good for runners, cyclists—anyone who wants to enjoy music and listen to podcasts or books but not totally tune out what's going on around them. These are not shut-out-the-world, airplane-travel airbuds. But they deliver good sound for music lovers who want to be safe while avoiding hearing loss.

Decibel levels in the AirDrives go no higher than 80 decibels, under the OSHA's standard 85-decibel maximum for all-day (8-hour) listening. Other earbuds can go as high as 110 decibels.

The kids earphones are made of light plastic and sell for $70, while the adult AirDrives are $100.