...from: http://www.apple.com/sound/ http://www.apple.com/pr/library/2006/mar/29ipod.html
Apple Provides Volume Limit Setting for iPod
Sound travels in waves, produced when an object — such as a stereo speaker — pushes on the air around it, causing small changes in air pressure. To describe sound waves, acoustic experts refer to concepts such as frequency and amplitude. [...]
Sound and Your Ears You can hear because your ears convert the vibrations of a sound wave in the air into signals that your brain interprets as sound. When the vibrations of a sound wave enter your ear, your eardrum and a set of tiny bones in your ear (the well-known hammer, anvil, and stirrup) amplify those vibrations. In your inner ear, these amplified vibrations move tiny hair cells that then convert the vibrations into nerve impulses sent to your brain. Your brain then interprets these nerve impulses as sound.
If you expose your ears to excessive sound pressure, you can harm those small hair cells in your ears. And if harmed, those hair cells can lose the ability to transmit sound to your brain. As a result, you could experience noise-induced hearing loss. Symptoms can include distorted or muffled sound or difficulty understanding speech.
While you can experience noise-induced hearing loss as a result of a one-time exposure to an extremely loud sound — like a gunshot — noise- induced hearing loss can also occur as a result of repeated exposure to loud sounds over time.
CUPERTINO, California—March 29, 2006—Apple® today announced a software update for the iPod® nano and fifth generation iPod, allowing customers to easily set their own personal maximum volume limit. The software update also gives parents the ability to set a maximum volume limit on their child’s iPod and lock it with a combination code.
“As the leading provider of digital music players, Apple continuously brings iPod customers innovative and easy to use solutions,” said Greg Joswiak, Apple’s vice president of Worldwide iPod Product Marketing. “With the increased attention in this area, we want to offer customers an easy to use option to set their own personal volume limit.”
The new software update 1.1.1 is available immediately as a free download for the iPod nano and the fifth generation iPod from www.apple.com/ipod/download. The new Volume Limit feature works with any headphone or accessory plugged into the iPod headphone jack as well as the iPod Radio Remote. For further information on safe listening with iPod, please visit www.apple.com/sound.
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Press Contacts: Tom Neumayr Apple (408) 974-1972 tneumayr@apple.com
Natalie Kerris Apple (408) 974-6877 nat@apple.com