I cut out the factory mufflers, and welded in some Cobra mufflers from Classic Chambered Exhaust. Not only is the exhaust note quieter, it has a more mellow sound. The factory pipes are not only loud, but harsh and "blatty". Tough on the ears, IMO.

Also, when driving down the highway, your exhaust note is generally not that loud or painfull. But wind, mechanical, and tire noise can really beat you up. Especially performance tires on concrete. That's the big reason for the ear plugs.