Ever sit next to someone on the bus or subway who was listening to their iPod so loud you couldn't think? Maybe you've been in the elevator with someone whose iPod is louder than the John Tesh Muzak oozing out of the speaker overhead.

Some people just listen to music in their headphones so loud that it's annoying. If you've ever felt this way, Apple's new iPod update with a maximum volume limit setting, may be music to your ears.

Apple has sold over 40 million iPods since October 2001, so why are they just adding this volume limit feature now? Apparently this is in response to Rep. Edward Markey (D-Mass.) who asked the National Institute of Health to investigate hearing problems associated with the iPod.

Many MP3 players, like the iPod, can produce volume levels as high as 120 decibels. FYI- That's as loud as a police siren. Prolonged exposure to 90 decibels or more may cause some hearing loss, according to the Mayo Clinic's Web site.

Parents worried about their children's hearing can even assign a combination to prevent the max volume setting from being changed. If they attempt to turn the volume all the way up after you've set a volume limit, then they will see a lock icon in the Now Playing screens volume bar.

The iPod update with the volume limit software is available as a free download on Apple's website.