Apple has registered a patent for a device enabling future iPods and iPhones to calculate automatically how long a person has been listening and at what volume before gradually reducing the sound level.
The move follows three years of meetings between the RNID and Apple. The charity has also campaigned to raise awareness of the link between loud music and hearing loss.
"The RNID is delighted that Apple has invested in developing technology that will protect its users' hearing," said Brian Lamb, executive director of communications. "We hope other manufacturers will follow suit and that mobile phones will be included in any new developments."