to me it's a general sound: the syndrum
that "be-ooo! be-ooo!" sound.
OMG how I hated them.
Once I saw a very good drummer demoing them at Manny's on 48th St. on a mixed acoustic/syndrum kit. Every now and then he would smack his tom - his real acoustic tom and "WHOOMPH!". It was thrilling.
I had been already waiting years
for electronic drums to arrive and when the Syndrum came out, I realized I would have to wait a few MORE years!
Of course today, these things are worth a small fortune. And I believe at least one company makes sample packs of them.