Duct Tape reduces vibration!

At a recent race I was oogling a friend's new Merckx Team SC. Gorgeous
blue purple with full Record, including carbon cranks. I asked him about
the carbon wrapped chainstays, an advertised feature, and he replied
that they were for vibration damping, saying that having the tubes
externally wrapped with something did this. He demonstrated the effect
by knocking on the top tube to produce a sound, then wrapped his palm
around the tube and knocked again, resulting in a muffled sound.

I then asked if duct tape wrapped around the bike would have the same
effect.

Silence.

Wayne