i belive what they used is called a vocoder...it will morph any 2 sounds together..ie that guy with a synth...or kid rock with a synth on his newest single.. do a search on the site for " vocoder" and youll find a previous post of mine asking what one was..someone pointed to a software plug in for one...
"i'm blue em dobble dee obble die, em dobble deeee obble die, em dobble de obble die..." repeated ad infinitum, with a techno beat in background. how that made top 40 is teh guess of anyone....