The suit, filed on Tuesday in US District Court in San Jose, California, charges that the iPod music player can produce sounds of up to 115 decibels even though some studies suggest that listening to music at that level for 28 seconds a day can cause damage over time. The suit, filed on behalf of John Kiel Patterson and all other iPod buyers, seeks monetary damages to compensate for the hearing loss suffered by iPod users, as well as a share of Apple's iPod profits.
The suit also seeks to force Apple to offer a software upgrade to limit the iPod's output to 100 decibels as well as provide headphones designed to block out external noise.
"Millions of consumers have had their hearing put at risk by Apple's conduct," the suit states.
An Apple representative declined to comment. The company has faced other suits over the iPod, including one over complaints that the devices scratch too easily. Apple reached a settlement in another case, related to the battery life of early iPods.
The latest court action follows several news articles quoting hearing experts who warn that prolonged digital music player use at high volumes may put people at risk of hearing loss.
Apple does caution customers in its iPod user manual, with a section labelled "Avoid Hearing Damage."
"Warning: Permanent hearing loss may occur if earphones or headphones are used at high volume," Apple states in the manual. "You can adapt over time to a higher volume of sound, which may sound normal but can be damaging to your hearing. Set your iPod's volume to a safe level before that happens."
The suit charges that the warning from Apple is inadequate because it fails to advise people what constitutes a "high volume" or a "safe level."
Apple was forced to limit the output of iPods to 100 decibels in France, although the suit claims that Apple has not done so in the US and that even that level is "still not safe."
Patterson's suit cites National Institute for Occupational Safety and Health data that sets a safe exposure limit for noise of 85 decibels for eight hours a day. For each 5-decibel increase, the safe exposure time drops by half, the suit says.
The suit was brought by lawyers at Hagens Berman Sobol Shapiro, one of two firms that filed the iPod scratching suit.
