Whenever I hear kids in stores talking about Dragonforce and the like as "noisy music", I smile to myself knowing that artists like Whitehouse, Merzbow and Masonna, who are total noise artists (imagine tuning in an FM radio, and you're close) exists, and are far louder and noisier. It's human nature, we just have to compete and that is what your friends are doing; just telling you they know of harder music, just like I was thinking back then.
Don't let your friends bug you man, and don't stop being their friend just 'cos of jibes like that! I get total shit from everyone where I work and friends in general for the music I listen to (even though I listen to their music as well as the other artists I like), and I don't let it bother me. If anything, I'm proud of the tunes I decide to inflict upon my ears, be it total noise, any types of metal, a forty minute jazz freakout, tibetan opera or Linkin Park remixes.