Talk-box WAS definitely overdubbed because if yoou've seen any other live performances (such as Live from London), Richie adds a few little "fills" during the intro and he does the mouth movement on the Crush DVD to play one of these fills........................and there's no change in the sound produced! I am a guitarist myself and I also own a talk-box so I know how the sounds are produced relative to mouth movement (its not rocket science ) and I can honestly say I don't think the DVD represents a live talk-box performance - sorry. The mouth movements don't match the sound produced in every place Richie's shown using it!