I don't know about The Wave,but the cleats defineately had a metallic sound to them when he was going up the walkway. It could have just been an echo in the enclosed part of the walkway.
Bubba and many others (McIlroy, Imada, ZJ) wear a metal-softspike hybrid made by Champs. It is basically the stinger spike that is stock on our FJ ICON with a metal spike coming out of the middle.
Golferdrmjr will like Bubba's comment on why he uses them, "I like the sound."