For all those riders addicted to music on the bike, this is interesting. http://www.ipodnn.com/articles/05/12/20/earbuds.hearing.loss/ "A Northwestern University professor and audiologist claims that the earbud-style headphones which ship with Apple's iPod and other MP3 players can cause serious, permanent hearing loss. "Insert earphones can boost the signal by as much as six to nine decibels. That's about the difference between the sound of a vacuum cleaner and a motorcycle," said Dean Garstecki, a professor at Northwestern. "It's a significant difference." The earbud-style headphones which rest inside the ear can lead to permanent damage after just an hour of high-volume music in the 110-120 decibel range, equivalent to the noise level of a concert, according to the professor. Garstecki says the large storage capacity of iPods also contributes to problems: "not only do you have a signal that is likely to be more intense, you're likely to be using this device longer than people have been using CD players and Walkmans in the past. This increases the likelihood of hearing loss down the road." The professor said that rock and rap music are the most dangerous, since they're typically played at a higher volume than other genres, such as classical or jazz, according to a report from InformationWeek. Garstecki recommends listening no more than an hour a day, switching to over-the-ear headphones, and turning down the volume on iPods to six or lower to minimize hearing loss. MacNN in mid-August reported the results of a study in Australia conducted by the National Acoustic Laboratories, suggesting that up to 25 percent of people will have hearing problems caused by listening to their iPods at "excessive and damaging" levels."