You guys have no idea what you're talking about.

JJ Fad clearly stated what the term Supersonic means:

"You see, the 'S' is for super, and the 'U' is for unique
The 'P' is for perfection and you know that we are freaks
The 'E' is for exotic, and the 'R' is for raps
So tell those nosy people just to stay the hell back "

OK, this song was stolen from Fergie, (as noted), BUT, Fergie stole it first from JJ Fad, an all girl rap group from the 80's. they put out one album and disbanded after one year! (Yup, I had the cassett Tape - Im Def, lol)

"Supersonic", their hit of 1988, and their song "Eenie Meenie Beats" was re-worked by Fergie into her single "Fergalicious" -Wikipedia
http://www.videosift.com/video/JJ-Fad-Supersonic