This problem can be solved much more easily: get a pair of good noise cancelling / in-ear headphones (Sony, Sennheiser et al.) and there's no need for high levels of volume anymore. For example, I listen to music for hours every day and I've never had to crank up the volume more than 50% on my Creative Zen because I have good headphones. (If you stood behind me and screamed or fired a gun and I wouldn't hear a thing.) Perhaps some consumer education is in place?