its not really suppose to be a distinctive "Fus ro dah".
Well, it IS though, for some race/gender combos. My Dark Elf Female shouts it distinctly. There's a pause between "Fus" and "Ro Dah" (same deal with the other shouts I've learned, even "Oh" and "Da Viing") but otherwise it's clear and distinct.
i can hear the deathlords yell fus ro dah but it's a disarm shout for them...i dont notice much difference with my nord and altmer shouts but i dont shout alot
Fus Ro Dah doesn't ever disarm. That's a different shout entirely, one which is known to some Draugr by default (and when facing an unarmed opponent, those same enemies use Fus Ro Dah instead), typically, as you said, Deathlords, but I've also seen Draugr Scourge use it.