Buddhist monks can waste their time wondering what the sound of one hand clapping is if they want, but as for me and Marvel Comics, we want to know what the sound of one hand crushing a demon alien's spine is. The answer:
That's "Fwak-tchh", from which (which as all linguists know) derives our modern "Fracture". Marvel, educating the mind and the blood lust at the same time for well over forty years.
(Images ©1993, Marvel Comics UK Ltd., "Battle Tide II")