Amid concerns of hearing damage for iPod owners - and to protect themselves against litigation-hungry users - Apple has filed a patent that will allow future iPods and iPhones to automatically calculate how long a person has been listening and at what volume before bringing down the sound to a level it deems safe for hearing.

Although only listening volumes below 70 decibels are considered safe, iPods can currently reach volumes of over 100 decibels. The new volume control system will also be able to calculate the amount of "quiet time" between when the iPod is turned off and when it is restarted, allowing the volume to be increased to a safe level. It is unclear at this point, however, if the automatic volume control feature will be user selectable or mandatory.