I remember riding next to a fellow on a Vitus 979 back when they were popular. He was a big fellow on what must have been a 59 or 60. The sounds coming out of that bike were horrifying. I'd have gotten off and walked, were it mine, but he told me it had always done that and that he'd put tens of thousands of miles on it. Never saw him again. Wonder if he lived.
I think a lot of the newer frames/materials are just very resonant. The oversize/odd shaped aluminum tubing especially. I had a brief relationship with one of GT's "Edge" aluminum bikes. Full aero tubes -- looked kind of like it had been run over by a steamroller -- that functioned exactly as a sounding board: every noise, no matter how slight, was amplified tenfold at least. Among the many reasons I got rid of it (thanks, Wes!) was all that damned racket.
Noel Hoffmann
Huntington Beach