Sentence:  In the prison of the 'tween decks reigned a darkness pregnant with <WSD>murmurs</WSD>. The sentry at the entrance to the hatchway was supposed to "prevent the prisoners from making a noise," but he put a very liberal interpretation upon the clause, and so long as the prisoners refrained from shouting, yelling, and fighting--eccentricities in which they sometimes indulged--he did not disturb them. 
Meaning of the word marked with <WSD> tags:  Soft indistinct speech.