I wear mine ALL THE TIME> I won't even do a 15 min ride without them. I'm a musician and can't afford to hurt my hearing any more. I use some walgreens Howard Leight Sleepers. Since they're meant for sleeping, you don't feel as much pressure as with regular ear plugs. It brings everything down in volume, but I can still hear everything, cars, engines, tires, horns, etc. They only drawback is when trying to talk from one vehicle to another at a stop light.
After I started wearing ear plugs, I noticed rides were more pleasing, and I was less tired when I would get to work. Something about the mind not being on the edge during the whole trip because of the excessive noise.
2003 Kawasaki Vulcan 500
16,484 miles when I bought it September 2011. 29,100 miles January 2014. All these miles have been enjoyable almost entirely thanks to this forum.