Is loud music bad for guinea pigs?

My roommate blasts his huge stereo all day, so bad that the house shakes. He had 2 piggys, but one "mysteriously" died. I'm worried that it might be the noise blasting into his poor little ears from only a few feet away. I've been telling him it's probably not good for his guinea but he doesn't believe me. Maybe if I approach him with facts I can stop him before it's too late for the other guinea left.