Apple has released a software update which, along with fixing a handful of bugs, enables users to set a maximum volume limit for their iPods. The 28 MB update supports both Mac OS X and Windows XP/2000, but applies only to Apple's fifth-generation video-capable iPods and the iPod nano.
<http://www.apple.com/support/downloads/ ipodupdater20060323.html>
<http://docs.info.apple.com/article.html? artnum=303414>
After installing the update, users can configure a maximum volume setting for their iPod: once set, the iPod displays a padlock icon when it reaches the configured top volume. Users can assign a password-like combination to the setting, which will enable parents and others to set a maximum volume that another user of that iPod won't be able to exceed. Apple has also published a set of informational guidelines about sound levels and iPod use.
The update comes amid growing concerns that high music volumes from iPods and other portable music devices may be contributing to hearing loss, particularly for folks who use the devices for extended periods of time. iPods (and most other digital music players) aren't necessarily any louder than other consumer electronics devices with headphones, but users tend to listen to iPods in noisy environments, and crank up the volume to drown out the noise around them. The noisier the environment, the louder they want their music, and the greater the potential for hearing loss.
Apple is currently facing a lawsuit over claims of hearing loss caused by iPod use, and French concerns over hearing loss caused Apple to alter the design of iPods sold in France to lower their maximum audio output.