The maker of the world's most deliriously successful music player offers these words of advice: "If you expose your ears to excessive sound pressure, you can harm those small hair cells in your ears." Whether this has anything to do with the class-action lawsuit filed in Louisiana alleging hearing damage from iPods is, of course, just so much irresponsible speculation. According to my colleagues at Stereophile, a recent poll indicates hearing loss among the young is a real problem. What is certain is that Apple has announced a firmware upgrade that sets a top volume level deemed safe with Apple's supplied iPod earbuds and other products with similar sensitivity ratings.