What are "troll-drums" ?

In reading a volume of writings by Nobel prize winners.  The sample used for Eugene O'Neill was his play "The Emperor Jones," in which background drumming is a prominent theatrical feature, as described in this commentary: 

The despot perishes on the flight from his glory, hunted in the dead of night by the troll-drums of his pursuers and by recollections of the past shaping themselves as paralyzing visions. 

Never heard of troll-drums, have difficulty adding a drum to my inner vision of trolls, can't quite derive the word from my understanding of "troll," and can't envision trolls in a Caribbean environment.
Can anyone clarify? May have missed an essential part of the folklore.