From D&D Wiki
traditionaly I think Harpies have played a SONIC based attack of a debilitating screech they eminate .
I have played a harpy and still do . and I have tried to read what I can find in christian/ greek and other ancient mythos on them .
I have never read anything related to any siren like qualities or lureing . Harpies were cursed to only be able to eat what they steal or earn .. as a curse from the gods ( sisters to goddess Iris , rumored illegitimate offspring of Zeus )
(( or the off spring of Satan and his various consorts )
any way the piont i s,, Sonic attacks , demoralisations , speed and theivery are generaly held constants in a Harpy character , that and they are exclusivly female.