Compressed music is actually worse for your ears than uncompressed music that has a great dynamic range.
Take this "uncompressed scenario", your in the car or walking using ear buds with much back ground noise.
A song starts of quite so you turn up the volume so to hear it over the background noise, then BANG!!! the first transient hits your ear drums and car speakers and have just been blown out of the park.
(and this is where compression is a good thing because there are no surprises)
Cheers George